Community Policing Grants: COPS Grants Were a Modest Contributor to Declines in Crime in the 1990s
Published: 2005-10-14T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: Between 1994 and 2001, the Office of Community Oriented Policing Services (COPS) provided more than $7.6 billion in grants to state and local communities to hire police officers and promote community policing as an effective strategy to prevent crime. Studies of the impact of the grants on crime have been inconclusive. GAO was asked to evaluate the effect of the COPS program on the decline in crime during the 1990s. GAO developed and analyzed a database containing annual observations on crime, police officers, COPS funds, and other factors related to crime, covering years prior to and during the COPS program, or from 1990 through 2001. GAO analyzed survey data on policing practices that agencies reportedly implemented and reviewed studies of policing practices. GAO assessed: (1) how COPS obligations were distributed and how much was spent; (2) the extent to which COPS expenditures contributed to increases in the number of police officers and declines in crime nationwide; and (3) the extent to which COPS grants during the 1990s were associated with policing practices that crime literature indicates could be effective. In commenting on a draft of this report, the COPS Office said that our findings are important and support conclusions reached by others.
section_title: What GAO Found
paragraphs: About half of the COPS funds distributed from 1994 through 2001 went to law enforcement agencies in localities of fewer than 150,000 persons and the remainder to agencies in larger communities. This distribution roughly corresponded to the distribution of major property crimes but less so to the distribution of violent crimes. For example, agencies in larger communities received about 47 percent of COPS funds but accounted for 58 percent of the violent crimes nationwide. From 1994 through 2001, COPS expenditures constituted about 1 percent of total local expenditures for police services. For the years 1994 through 2001, expenditures of COPS grants by grant recipients resulted in varying amounts of additional officers above the levels that would have been expected without the expenditures. For example, during 2000, the peak year of COPS expenditures by grant recipients, they led to an increase of about 3 percent in the level of sworn officers--or about 17,000 officers. Adding up the number of additional officers in each year from 1994 through 2001, GAO estimated that COPS expenditures yielded about 88,000 additional officer-years. GAO obtained its results from fixed-effects regression models that controlled for pre-1994 trends in the growth rate of officers, other federal expenditures, and local- and state-level factors that could affect officer levels. From its analysis of the effects of increases in officers on declines in crime, GAO estimated that COPS funds contributed to declines in the crime rate that, while modest in size, varied over time and among categories of crime. For example, between 1993 and 2000, COPS funds contributed to a 1.3 percent decline in the overall crime rate and a 2.5 percent decline in the violent crime rate from the 1993 levels. The effects of COPS funds on crime held when GAO controlled for other crime-related factors--such as local economic conditions and state-level policy changes--in its regression models, and the effects were commensurate with COPS funds' contribution to local spending on police protection. Factors other than COPS funds accounted for the majority of the decline in crime during this period. For example, between 1993 and 2000, the overall crime rate declined by 26 percent, and the 1.3 percent decline due to COPS, amounted to about 5 percent of the overall decline. Similarly, COPS contributed about 7 percent of the 32 percent decline in violent crime from 1993 to 2000. From 1993 though 1997, agencies that received and spent COPS grants reported larger changes in policing practices and in the subsets of practices that focus on solving crime problems or focus on places where crime is concentrated than did agencies that did not receive the grants. The differences held after GAO controlled for underlying trends in the reported use of these policing practices. From 1996 to 2000, there was no overall increase in policing practices associated with COPS grants. In its review of studies on policing practices, GAO found that problem-solving and place-oriented practices can be effective in reducing crime.

section_title: Letter
paragraphs: Provisions of the Public Safety Partnership and Community Policing Act of  1994, Title 1 of the Violent Crime Control and Law Enforcement Act of  1994 (VCCLEA), authorized appropriations of $8.8 billion for fiscal years  1995 through 2000 for grants to states and local communities to increase  the hiring and deployment of community police officers and to promote  nationwide the concept of community policing—an approach to policing  that involves the cooperation of law enforcement and community  residents in identifying and developing solutions to crime problems—as an  effective strategy to improve public safety.  To administer the grants, in  October 1994, the Attorney General created the Office of Community  Oriented Policing Services (COPS).
According to its Director, the COPS Office was responsible for “one of the  greatest infusions of resources into local law enforcement in our nation’s  history,” and in a report to Congress the former Attorney General linked  increases in COPS-funded officers to declines in crime. By the summer of  2000, the former Attorney General reported, the COPS Office had awarded  more than $7.6 billion in grants to more than 12,000 local law enforcement  agencies—primarily municipal, state, and county police and sheriff’s  departments whose officers have general arrest powers—and funded over  105,000 community policing officers.  The report claimed that the funded  officers led to an increase in the number of police officers that was well  above what would have been expected in the absence of the passage of  VCCLEA, and it cited research that showed that increased police presence  led to reductions in crime. As evidence that these officers led to  reductions in crime, the report showed that the average number of violent  crimes per police department declined as the number of COPS-funded  officers increased.
A study funded by the COPS Office and released in 2001, which attempted  to control for some of the other factors that could influence crime rates  and also be correlated with the distribution of COPS funds, concluded that  COPS grants contributed to the reduction in crime in the 1990s. You  previously asked us to review this study, and we reported that its  methodological limitations were such that the study’s results should be  viewed as inconclusive.
In response to our assessment of the results of the study that we reviewed,  you asked us to undertake an independent evaluation of the impact of  COPS grants on the decline in crime that occurred during the 1990s. This  report provides results from our evaluation of interrelated questions about  COPS funds, officers, crime, and policing practices. Specifically, regarding  COPS funds: (1) From 1994 through 2001, how were COPS obligations  distributed among local law enforcement agencies in relation to the  populations they served and crimes in their jurisdictions, and how much of  the obligated amounts did agencies spend?  Regarding officers and crime:  (2) To what extent did COPS grants contribute to increases in the number  of sworn officers and declines in crime in the nation during the 1990s?  Regarding policing practices: (3) To what extent were COPS grants during  the 1990s associated with police departments adopting policing practices  that the crime literature indicates could contribute to reductions in crime?
To address our reporting objectives, we created and analyzed a database  consisting of 12 years of data on local law enforcement agencies for the  years 1990 through 2001. We included data from the Department of  Justice’s (DOJ) Office of Justice Programs (OJP) on federal law  enforcement grant obligations and expenditures (including COPS grants);  the Federal Bureau of Investigation’s (FBI) Uniform Crime Reporting  (UCR) Program on crime and sworn officers; the Department of  Commerce’s Bureau of Economic Analysis on local economic conditions  such as employment rates and per capita income; and the National Center  for Health Statistics and U.S. Census Bureau’s estimates of demographic  characteristics of local populations—such as their age, race, and gender  composition. The UCR crime data that we used are data on crimes  reported to or known by the police and reported to the UCR Program. The  crimes in the UCR are based on the FBI’s crime index. The index crimes  include the violent crimes of murder and non-negligent manslaughter,  forcible rape, robbery, and aggravated assault as well as the property  crimes of burglary, larceny-theft, motor vehicle theft, and arson. The FBI  reports that there is limited reporting of arson offenses to the UCR  Program by law enforcement agencies. We therefore excluded arson  crimes from our analysis.
Prior to developing and using the database to address our objectives, we  assessed the reliability of each data source, and in preparing this report,  we used only the data that we found to be sufficiently reliable for the  purposes of our report. We also assessed possible biases in our estimates  of the effects of COPS funds on crime arising from our use of UCR data on  reported crimes. We concluded from our analysis that our estimates of the  impacts of COPS funds are likely to understate the effect of COPS funds  on crime. (See app. I for a more detailed discussion of our approach,  methods, and database construction.)
To describe how COPS grant funds were distributed and spent, we  analyzed data on COPS obligations to and expenditures by local law  enforcement agencies, comparing them with several characteristics of the  agencies that received COPS funds, such as population size and crime  levels.
To assess the possible relationships between COPS expenditures and  changes in the number of officers and rates of crime, we analyzed data on  the agencies that reported complete crime and officer data for at least 1  year from 1990 through 2001 using a two-stage regression model of these  relationships. In the first stage, we estimated the relationship between the  variation in the timing and amount of agencies’ expenditures on COPS  grants that were for hiring officers and changes in the number of officers.  In the second stage, we estimated the relationship between changes in  COPS expenditures and changes in crime rates using fixed-effects  regression models. We used the results from these two sets of regressions  to calculate the amount of the change in crime (from the second stage)  due to changes in officers (from the first stage). As the relationship  between officer levels and crime rates may reflect a complex causal  relationship, we used COPS hiring grants as a statistical instrument to help  to identify the relationship between officers and crime. In both sets of  regression models, we used agency and year fixed effects to control for  unobserved sources of variation among agencies (within a given year) and  within agencies (over time). We also included variables to measure  agencies’ pre-1994 trends in the growth of crime rates and officers. These  controls allowed us to compare agencies that had similar, pre-COPS trends  in these variables, thereby reducing further the differences among  agencies that are not due to COPS expenditures. To control for economic  factors that may be related to crime—such as employment and income— we included measures of local economic conditions, and to control for  changes in the composition of local populations that could be correlated  with crime, we included measures of age and race composition of local  populations. Finally, to control for changes in state-level practices that  could affect crime rates, such as changes in state incarceration rates or  state sentencing policy, we included state-by-year fixed effects in our  regression models. (See app. VI for additional details about our regression  models.)
To address the relationship between COPS grants and changes in policing  practices, we analyzed data from two surveys of nationally representative  samples of local law enforcement agencies on policing practices that they  reportedly implemented in various years from 1993 to 2000. The first  survey—the Policing Strategies Survey—was administered in 1993 and  1997 to provide information on the development and implementation of  community policing. The second survey—the National Evaluation of  COPS Survey—was administered in 1996 and 2000. We identified and  analyzed practices that are associated with problem-solving, place- oriented approaches to policing, community collaboration efforts, and the  use of crime analysis. We assessed changes in the levels of reported  practices between agencies that spent COPS grants over particular periods  with those that did not receive or spend COPS grant funds. To control for  the underlying trends in reported policing practices, we estimated fixed- effects regression models of the effects of COPS grants expenditures on  changes in reported policing practices.  To assess the possible relationship  between policing practices and crime, we analyzed systematic reviews of  the effectiveness of policing practices in reducing crime to identify the  types of policing practices that have been judged to be effective in  preventing crime. (See app. VII for details about the surveys and our  analytic methods.)
In addition, we reviewed relevant economic and criminological literatures  that addressed issues related to estimating models of the effects of federal  grant funds on crime rates. We spoke with officials at the Department of  Justice about the operation of the COPS program, and we also spoke with  researchers about our approach and methods. We reviewed our approach  and methods with a group of experts in the field of policing and crime. The  group consisted of criminologists, economists, statisticians, and criminal  justice practitioners, and was convened for us by the National Research  Council of the National Academies to enable participants to offer their  individual views as experts in the field.
We conducted our work between January 2004 and August 2005 in  accordance with generally accepted government auditing standards.
subsections: section_title: Background
paragraphs: Established in October 1994 by the Attorney General to implement the  administration of community policing grants under VCCLEA, the Office of  Community Oriented Policing Services announced it first grant programs  in 1994. Prior to its establishment, in December 1993 the Department of  Justice awarded community policing grants to hire officers under the  Police Hiring Supplement.
The COPS Office distributed grants in a variety of program funding  categories. Hiring grants, which required agencies to hire new officers and  at the same time to indicate the types of community policing strategies  that they intended to implement with the grants, was the largest COPS  grant program category in terms of the amounts of grant funds obligated.  The hiring grants paid a maximum of $75,000 per officer over a 3-year  period (or at most 75 percent of an officer’s salary) and generally required  that local agencies cover the remaining salary and benefits with state or  local funds. From 1994 through 2001, more than $4.8 billion in COPS  obligations (or about 64 percent of COPS obligations over this period)  were in the form of hiring grants. The Making Officer Redeployment  Effective (MORE) grant program, which provided funds to law  enforcement agencies to purchase equipment, hire civilians, and redeploy  existing officers to community policing was the second largest COPS grant  program, obligating more than $1.2 billion. Additional COPS grant  programs provided funds for specific innovations in policing and for a  variety of other purposes.
Each year the COPS Office was required to distribute half of the grant  funds to agencies in communities whose populations exceeded 150,000  persons and half of the grant funds to agencies in communities with  populations of 150,000 or fewer persons.
In the applications for hiring grants, the COPS Office requested agencies to  indicate the types of community policing practices that they planned to  implement with their grants. The various practices related to community  policing included practices such as identifying crime problems by looking  at records of crime trends and analyzing repeat calls for service, working  with other public agencies to solve disorder problems, locating offices or  stations within neighborhoods, and collaborating with community  residents by increasing officer contact with citizens and improving citizen  feedback. These types of policing practices also corresponded with  general approaches to policing. For example, problem-solving policing  practices may rely on crime analysis tools to help to identify crime  problems and develop solutions to them.  Place-oriented practices attempt  to identify locations where crime occurs repeatedly and to implement  procedures to disrupt these recurrences of crime. By collaborating with  community residents, agencies attempt to improve citizen feedback about  crime problems and effectiveness of policing to address these problems.
In 2000, DOJ reported that COPS-funded officers helped to reduce crime  and reported that the drop in crime that occurred after 1994 was more  than what would have been expected in the absence of the passage of  VCCLEA and the creation of the COPS Office. The report suggested that  COPS had achieved its goal of funding 100,000 officers, and through  increases in officers and the practice of community policing, the COPS  program was credited with reducing crime. However, while COPS may  have funded 100,000 officers, it was not apparent that the funded officers  had resulted in new officers having been hired. Researchers at the Urban  Institute reported in 2000, for example, their estimates that by 2003, the  COPS program would have raised the level of police on the street by the  equivalent of 62,700 to 83,900 full-time equivalent officers. They also  indicated that it was unclear whether the program would ever increase the  number of officers on the street at a single time by 100,000.
The COPS Office-funded study of the effect of COPS grants on crime in  over 6,000 communities from 1995 through 1999 that had received COPS  grants concluded that COPS grants were effective in reducing crime. The  study also reported that COPS grants that encouraged agencies to  implement a variety of innovative strategies to improve public safety had  larger impacts on reducing violent and property crime than did other  COPS grant types. However, a study released by the Heritage Foundation,  which was based upon an analysis of county-level data, was unable to  replicate the findings of the COPS Office-funded study.  Specifically, the  Heritage study found no effect of COPS hiring grants on crime rates, but it  did find that the COPS grants for specific problems—such as gangs,  domestic violence, and illegal use of firearms by youth—were associated  with reductions in crime. In addition, we questioned whether the sizes of  the effects of COPS grants on crime that were reported in the COPS  Office-funded study were large enough to be significant in a practical  sense and whether they could accurately represent the expected returns  on the investment of billions of dollars.
Assessing the contribution of COPS funds to the decline in crime during  the 1990s presents challenges for evaluators. Nationwide, crime rates  began to decline in about 1991, before the COPS program announced its  first grant programs in 1994 (fig. 1). Hence the factors other than COPS  grants that were responsible for precipitating the decline in crime could  have continued to influence its decline throughout the 1990s. Researchers  have pointed to a number of factors that could have precipitated the  decline in crime, including increased use of prison as a punishment for  violent crimes, improved economic conditions, and the subsiding of  violence that accompanied the expansion of drug markets. To the extent  that any of these factors are correlated with the distribution of COPS  grants, they could be responsible for impacts that have been attributed to  COPS grants.
Prior studies of the impact of COPS grants on crime have correlated COPS  funds with crime rates, controlling for other factors that could influence  crime rates. The authors of the prior studies describe various mechanisms  by which COPS grants may affect crime, but their statistical models do not  explicitly take these mechanisms into account in estimating the effects of  the grants. By identifying and explicitly modeling mechanisms through  which COPS funds could affect crimes—such as increasing the number of  sworn officers on the street who are available for patrolling places or  contributing to changes in policing practices that may be effective in  preventing crime—the possibility of a spurious relationship between inputs  (such as COPS funds) and outcomes (such as crime) can be minimized.  (For additional background information, see app. II.)
section_title: Results
paragraphs: Our analysis showed that from 1994 through 2001, COPS obligated more  than $7.32 billion to 10,680 agencies for which we were able to link Office  of Justice Programs financial data on COPS obligations to the records of  law enforcement agencies. About $4.7 billion (or 64 percent) of these  obligations were in the form of hiring grants.  About half of these funds  went to agencies serving populations of 150,000 or fewer persons and  about half was distributed to agencies serving populations of more than  150,000 persons. This distribution roughly corresponds to the distribution  of index crimes across the two size categories of jurisdictions. However, in  relation to violent crimes, the share of COPS funds distributed to larger  jurisdictions was smaller than the share of violent crimes that they  contributed to the national total. For example, agencies serving  populations of more than 150,000 persons contributed about 58 percent of  all violent crimes reported to the UCR during this time period while  receiving about half of all COPS funds. To be specific, the smallest  agencies—those serving populations of fewer than 10,000 persons— received an average of $1,573 per violent crime reported to UCR. Agencies  serving populations of more than 150,000 persons received about $418 in  COPS funds per violent crime.
By the end of 2001, the COPS grantee agencies in our sample had spent  about $5 billion (or 68 percent of the $7.3 billion obligated to them) from  1994 through 2001. Annually, the total amount of COPS expenditures made  by grantees increased each year from 1994 until 2000, and then declined,  while the number of agencies that drew down COPS funds peaked in 1998  at about 7,600 and declined to about 6,000 in 2001. From 1994 through  2001, a total of about 10,300 agencies spent COPS funds.  The maximum  number of agencies spending funds in any given year occurred during  1998, when about 7,600 agencies spent funds. From 1998 through 2000, the  amount of COPS expenditures per person in the jurisdiction served by an  agency increased from about $4 to about $4.80. COPS expenditures  amounted to an annual average of about 1 percent of total expenditures  for police services by local law enforcement agencies from 1994 through  2001.  This contribution varied by year.  For example, in 1999 and 2000,  COPS expenditures were about 1.5 percent of total local police  expenditures. (See app. III for a further discussion of COPS obligations  and expenditures.)
For the years 1994 through 2001, we infer from our estimates that COPS  hiring grant expenditures contributed to increases in sworn officer levels  above the levels that would have been expected without these funds. The  additional number of sworn officers stemming from these funds varied  over the years, and it increased from 1994 though 2000 and declined in  2001 (fig. 2). For example, for 1997 we estimate that COPS funds  contributed about 14,000 additional officers in that year—or about 2.4  percent of the total number of sworn officers nationwide—and for 2000,  COPS funds contributed about 17,000 additional officers—or about 3  percent of the total number of sworn officers nationwide. For all years  from 1994 through 2001, we estimate that COPS expenditures paid for a  total of about 88,000 additional officer-years over this entire period, where  the total number of officer-years equals the sum of the number of officers  due to COPS grant expenditures in each year. An officer-year refers to the  number of officers in a given year that we could attribute to COPS  expenditures, and the additional officers in a given year attributable to  COPS expenditures represent a net addition to the stock of sworn  officers. Using the results from our regression estimates of the effects of  COPS expenditures on the level of sworn officers, we set the values for  COPS expenditures to zero to predict the level of officers absent COPS  funds. The difference between this number and the actual number of  sworn officers yields the number of officers due to COPS expenditures.  Our analysis also shows that apart from the COPS hiring and COPS MORE  grants, other COPS grant types did not have a significant effect on officer  strength. (See app. IV for more detailed information about the results of  our analysis of COPS expenditures on officers.)
We estimate that the COPS grant expenditures contributed to the  reduction in crime in the 1990s independently of other factors that we  were able to take into account in our analysis. Other factors that could  have contributed to the reduction in crimes in the 1990s that we took into  account included federal law enforcement expenditures other than COPS  grants, local economic conditions and changes in population composition,  and changes in state-level policies and practices that could be correlated  with crime, such as incarceration and sentencing policy. Specifically, from  our model of the effect of changes in sworn officers on crime, we estimate  that a 1 percent increase in the number of sworn officers per capita would  lead to a 0.4 percent reduction in the total number of index crimes.  Through their effects on changes in officers in a given year, COPS  expenditures led to varying amounts of declines in crime rates over the  years from 1994 through 2001. For example, the 2.4 percent increase in  sworn officers due to COPS expenditures in 1997 was responsible for  about a 1.1 percent decline in the total index crime rate from 1993 to 1997,  while the roughly 3 percent increase in officers due to COPS expenditures  in 2000 was responsible for about 1.3 percent decline in the total index  crime rate from 1993 to 2000.  Put into another context, the total crime  rate declined from 5,904 per 100,000 persons in 1993 to 4,367 per 100,000  persons in 2000, or by about 26 percent. Of this 26 percent drop, we  attribute about 5 percent to the effect of COPS.  From our analysis of  violent crimes, we estimated that declines in the violent crime rate due to  COPS expenditures also varied with the level of officers due to COPS  funds. The declines in violent crime rates attributable to COPS increased  from about 2 percent in 1997 to 2.5 percent in 2000, where both of the  amounts of decline attributable to COPS expenditures are based upon  comparisons with the 1993 violent crime rate (fig. 3). We further estimate  that at its peak in 1998, COPS accounted for about a 1.2 percent decline in  the property crime rate.
Our estimates of the impacts of COPS expenditures on the broad  categories of crime are supported by our findings from our crime-type- specific regression models. We find significant reductions due to COPS  expenditures for the crimes of murder and non-negligent manslaughter,  robbery, aggravated assault, burglary, and motor vehicle theft. Our  analysis of larceny indicates that while the relationship between COPS  funds and larceny is a negative one, it is not statistically significant, nor is  the effect of COPS on rape statistically significant. Further, we estimated  the effects of COPS grants on the total crime rate under various  assumptions about lags between the receipt of COPS grants and  expenditures of COPS funds. The estimates for the amount of the decline  in the total crime rate that we report here—for example, the 1.3 percent of  the decline in crime from 1993 to 2000—are among the smallest effects  that we estimated from our various models.  Under different assumptions  about lags associated with COPS expenditures, the amount attributable to  COPS could be as high as 3.2 percent.  Interestingly, the 1.3 percent  decline in the index crime rate that we attribute to COPS expenditures in  2000 is on the same order of magnitude as the contribution of COPS  expenditures to total local spending on police.  In 2000, for example, COPS  expenditures accounted for about 1.5 percent of total local police  expenditures. We further find that factors other than COPS expenditures  account for the majority of the decline in the crime rate. (See app. IV for  more detailed information about the results of our analysis of COPS  expenditures on crime.)
Our regression analysis of the Policing Strategies Survey data for 1993 and  1997 indicate that receipt of a COPS grant and the amount of per capita  COPS expenditures by agencies were associated with increases in the  agencies’ reported use of problem-solving and place-oriented policing  practices but not crime analysis and community collaboration policing  practices (fig.4). According to our review studies of the effectiveness of  policing practices, problem-solving and place-oriented practices are  among those that the crime literature indicates may be effective in  reducing crime. With problem-solving practices, police focus on specific  problems and tailor their strategies to them. Place-oriented practices  include efforts to identify the locations where crime repeatedly occurs and  to implement procedures to disrupt these recurrences of crime. Crime  analysis includes the use of tools such as geographic information systems  to identify crime patterns. Community collaboration includes attempts to  improve or enhance citizen feedback about crime problems and the  effectiveness of policing efforts to address them. In our regressions, we  controlled for the underlying trends in the reported adoption of policing  practices, agency characteristics, and local economic conditions.
Our analysis of the National Evaluation of COPS Survey—which measured  practices in 1996 and again in 2000—showed that while COPS grantee  agencies increased their reported use of all policing practices combined,  these changes were not statistically significant in regressions that  controlled for the underlying trends in the reported adoption of policing  practices, agency characteristics, and local economic conditions. (See app.  V for more detailed information about the results of our analysis of COPS  expenditures and policing practices.)
section_title: Concluding Observations
paragraphs: While we find that COPS expenditures led to increases in sworn police  officers above levels that would have been expected without these  expenditures and through the increases in sworn officers led to declines in  crime, we conclude that COPS grants were not the major cause of the  decline in crime from 1994 through 2001. Other factors—which other  researchers have attempted to sort out—combined to contribute more to  the reduction in crime than did COPS expenditures. This is not surprising,  as COPS expenditures—while a large federal investment in local law  enforcement—made a comparatively small contribution to local law  enforcement expenditures for policing.
Nevertheless, our analysis shows that COPS grant expenditures did reduce  crime during the 1990s. Our models isolate the effects of COPS  expenditures from the effects of other factors.  We cannot identify another  variable that is correlated with changes in COPS expenditures, officers,  and crime rates in local communities that would explain away our  findings.  Thus, we conclude that the results of our model are sound.  Further, our results do not address whether the COPS program met its  goals of putting 100,000 officers on the street—and the evidence suggests  that while it funded more than 100,000 officers, it may have fallen short of  achieving this goal.  Still, through the increases in officers that we attribute  to COPS expenditures, we find that COPS grants affected crime rates.  Therefore, as a demonstration of whether a federal program can affect  crime through hiring officers and changing policing practices, the evidence  indicates that COPS contributed to declines in crime above the levels of  declines that would have been expected without it.
Our work cannot identify an optimum number of officers needed by any  individual agency to maximize the effect of officers on reducing crime, nor  can it identify the specific types of practices that agencies should adopt in  particular settings. It is highly likely that there is indeed a point where  additional officers no longer affect crime. The numbers of additional  officers hired as a result of COPS were relatively small compared with the  sizes of individual police agencies, and these small increases led to  commensurate reductions in crime rates. Given resource constraints and  competing priorities at all levels of government, it is probably unlikely that  most police agencies would have the resources available to hire large  enough numbers of officers to go past the point of diminishing returns.
section_title: Agency Comments and Our Evaluation
paragraphs: We provided a draft of this report to the Attorney General for comment on  September 13, 2005.  In its written comments, the Office of Community  Oriented Policing Services (COPS) drew upon information from both this  report and our prior correspondence on the effects of COPS grants on  crime.  They said that we were careful and diligent in our research, and  that our findings support conclusions reached by others and correspond  with what local law enforcement leaders report.  The COPS Office also  expanded upon some of our main findings, which they characterized  correctly.  In their comments, the COPS Office introduced data and  opinions about potential effects of the COPS grants that were beyond the  scope of our work.  We therefore cannot corroborate these statements.
For example, in discussing our findings about the effects of COPS grants  on sworn officers, the COPS Office introduced data about officers derived  from the MORE technology grants and reports that 42,058 (or 36 percent)  of the 118,397 officers that the COPS Office has funded to date are derived  from the MORE grants.  Our work does not corroborate either of these  figures.  We point out in Appendix VI that our estimates of a total of 88,000  additional officer-years takes into account the effects of MORE grant  expenditures.
In their comments on our finding about changes in policing practices that  resulted from COPS, the COPS Office points out that the aggregate counts  of policing practices that we used in our analysis provide only a superficial  measure of the level of community policing taking place.  We  acknowledged this point in appendix VII, but chose not to speculate on the  extent to which police departments increased the amount of problem  solving or other policing practices they engaged in.  By speculating that  agencies may have increased the quantity of a specific activity, the COPS  Office provides only one view of what may have happened.  Another view,  proffered by policing researchers, is that there is little evidence to suggest  that problem-solving policing was implemented with sufficient rigor in  enough departments to have contributed to declines in violent crime  during the 1990s.  As they point out, problem-solving activities may have  increased, and they may have contributed to declines in crime, “but we  simply do not know.”
We are sending copies of this report to other interested congressional  committees and the Attorney General.  We will also make copies available  to others upon request. In addition, the report will be available at no  charge on GAO’s Web site at http://www.gao.gov.
If you or your staff have any questions concerning this report, please  contact Laurie Ekstrand at (202) 512-8777 or by e-mail at  Ekstrandl@gao.gov or Nancy Kingsbury at (202) 512-2700 or by e-mail at   Kingsburyn@gao.gov. Contact points for our Offices of Congressional  Relations and Public Affairs may be found on the last page of this report.  Key contributors to this report are listed in appendix IX.
section_title: Appendix I: Objectives, Scope, and Methodology
paragraphs: In response to a request from F. James Sensenbrenner, Jr., Chairman,  Committee on the Judiciary, House of Representatives, this report  provides the findings of our evaluation of the impact of Community  Oriented Policing Services (COPS) grants on the decline in crime that  occurred during the 1990s. Our objectives were to address interrelated  questions about COPS funds, officers, crime, and policing practices.  Specifically, regarding COPS funds: (1) From 1994 through 2001, how were  COPS obligations distributed among local law enforcement agencies in  relation to the populations they served and crimes in their jurisdictions,  and how much of the obligated amounts did agencies spend?  Regarding  officers and crime: (2) To what extent did COPS grants contribute to  increases in the number of sworn officers and declines in crime in the  nation during the 1990s? Regarding policing practices: (3) To what extent  were COPS grants during the 1990s associated with police departments  adopting policing practices that the crime literature indicates could  contribute to reductions in crime?
subsections: section_title: Overview of Our Approach and Methodology
paragraphs: To address our reporting objectives, we analyzed a database consisting of  12 years of data from 1990 through 2001 on local law enforcement  agencies. To create this database—our primary analysis database—we  obtained data from several sources, and we organized the data as a panel  dataset in that it contained information on multiple law enforcement  agencies over multiple years. For each agency, we obtained data on COPS  and other federal law enforcement grant obligations and expenditures  from the Department of Justice’s (DOJ) Office of Justice Programs (OJP),  and data on index crimes and the number of sworn officers from the  Federal Bureau of Investigation’s (FBI) Uniform Crime Reporting (UCR)  Program. Index crimes include the violent crimes of murder and non- negligent manslaughter, forcible rape, robbery, and aggravated assault, as  well as the property crimes of burglary, larceny-theft, motor vehicle theft,  and arson. As shown in table 1, in 2002, property crimes constituted 88  percent of the 11,877,218 index crimes. Among violent crimes, robberies  accounted for 3.5 percent of all index crimes, and aggravated assaults  accounted for 7.5 percent.
We obtained data on some of the factors that the research literature on  crime suggests are related to changes in crime. From the Department of  Commerce’s Bureau of Economic Analysis, we obtained data on local  economic conditions—including employment rates and per capita  income—and from the National Center for Health Statistics and the U.S.  Census Bureau—we obtained data on demographic variables—including  the percentage of the population aged 15 to 24, and the racial and gender  composition of the population.
We also analyzed data from two surveys of nationally representative  samples of police departments on the policing practices that they  reportedly implemented in various years from 1993 to 2000. We refer to the  first survey as the Policing Strategies Survey, and it was administered in  1993 and again in 1997. We refer to the second survey as the National  Evaluation of COPS Survey, as it was completed as part of the Urban  Institute’s national evaluation of the implementation of the COPS program,  and we used the data from the surveys that were administered in 1996 and  2000.  The multiple administrations of each survey allowed us to analyze  changes in policing practices. Using agency and year identifiers, we  matched and merged data from our primary analysis database with the  agency-level records in each of the surveys.
Prior to developing and analyzing our database, we assessed the reliability  of each data source, and in preparing this report, we used only the data  that we found to be sufficiently reliable for the purposes of our report.
In addition, to identify policing practices that are considered to be  effective in preventing crime, we analyzed reviews of research and  evaluation literature. We also reviewed relevant economic and  criminological literatures that addressed issues related to estimating  models of the effects of federal grant funds on crime rates. We spoke with  officials at the Department of Justice about the operation of the COPS  programs, and we also spoke with researchers about our approach and  methods. We reviewed our approach and methods with a group of experts  in the field of policing and crime. The group consisted of criminologists,  economists, statisticians, and criminal justice practitioners, and was  convened for us by the National Research Council of the National  Academies to enable participants to offer their individual views as experts  in the field.
We conducted our work between January 2004 and August 2005 in  accordance with generally accepted government auditing standards.
subsections: section_title: Methods Used to Address the Flow of Funds Reporting Objective
paragraphs: To address our first objective, we analyzed OJP financial system data on  grant obligations and expenditures and UCR data on the size of  populations served by agencies and crimes occurring within the  jurisdictions of the agencies that reported crime to the UCR. We used the  OJP financial data to compute the amount of COPS funds obligated by  COPS grants and the amount expended by local police agencies during the  period from 1994 through 2001. To describe the overall COPS funding  trends by grant type, we analyzed the universe of agencies in the OJP data  that received any federal law enforcement grant during the period from  1990 through 2001, regardless of whether or not the agency received a  COPS grant during the period and regardless of whether we were able to  link the data from these agencies to records in the UCR. For the years  from 1990 through 2001, the OJP data show that 13,332 agencies received  any federal law enforcement grant. For analyses of COPS funds by agency  population sizes and for comparisons of funding levels with levels of  violent and total index crime, we limited our analysis to the sample of  agencies whose crime and population data we were able to link to the OJP  data. This resulted in a sample of 11,187 agencies in our primary analysis  database. These 11,187 agencies accounted for 86 percent of the reported  crimes in the UCR data that we received from the FBI.
The COPS Office distributed grants in a variety of programs. To describe  the amounts of COPS obligations and expenditures, we organized the  COPS grant programs into four broader categories of grants, and we  reported our results at the level of these broader categories. These four  categories include: Hiring, Making Officer Redeployment Effective  (MORE), Innovative, and Miscellaneous grants, and the specific grant  programs within each category, along with obligated amounts from 1994  through 2001 for each grant program and category, are shown in table 2.
In our analysis, we compared the distribution of COPS obligations with the  distribution of crimes contributed by agencies serving populations of   150,000 or fewer persons and those serving more than 150,000 persons. We  used UCR population to identify agency size and crimes. The UCR  population may not reflect the population that agencies provided on the  applications for COPS grants. Our analysis of the distribution of COPS  funds describes the extent to which the distribution of funds is related to  agency size—as measured by populations served—and the distribution of  violent crimes.
section_title: Methods Used to Address the Effects of COPS Expenditures on Officers and Crime
paragraphs: To assess the effects of COPS expenditures on the number of sworn  officers and crime, we developed and estimated a two-stage regression  model of these relationships. In the first stage, we estimated the  relationship between per capita COPS expenditures and per capita sworn  officer rates in the agencies included in our sample. The per capita  measures were based upon the UCR population for the jurisdiction  covered by an agency. In the second stage, we estimated the relationship  between changes in per capita COPS expenditures and changes in crime  rates per 100,000 persons. As the relationship between officer levels and  crime rates may reflect a complex and interrelated causal relationship, we  used COPS hiring grants as an instrument to help to identify the  relationship between officers and crime. To use COPS hiring grant  expenditures as an instrument for sworn officers, we made use of the fact  that, unlike the purposes of other COPS grant types, the purpose of hiring  grants was limited to hiring officers. Given the number of officers,  variation in hiring grant expenditures should be uncorrelated with other  changes in crime. From our regression results, we calculated the elasticity  of crime with respect to officers or the effect of a 1 percent change in the  levels of officers on the percentage change in crime. To assess the  robustness of our results, we estimated several specifications of our crime  rate regression and calculated the elasticities of crime with respect to  officers for each specification. We estimated these equations separately  for each type of index crime. We compared the range of our estimated  elasticities with those in the published literature on officers and crime. To  estimate COPS’ contribution to the national decline in crime, we projected  our sample results to the nation as a whole by weighting our results by the  ratio of the total population in the United States to the population in the  sample of agencies included in our analysis.
In our regression models of the effects of COPS grant expenditures on  officers and crime, we organized our primary analysis database as a panel  dataset, and we limited our analysis to the 4,509 law enforcement agencies  serving populations of 10,000 or more persons and that reported complete  crime data for at least 1 year from 1990 through 2001.  The number of  agencies that reported complete crime data and served populations of  10,000 or more persons varied over time, as in 1990 about 23 percent of all  agencies in the UCR data that we received from the FBI met these criteria,  and in 2001 about 21 percent did.  However, these agencies also reported  the majority of crimes to the UCR.  From 1990 through 2001, these  agencies reported between 86.8 percent and 88.8 percent of all index  crimes in the UCR data that we received from the FBI.  Because of data  concerns with agencies serving populations of fewer than 10,000 persons,  we omitted these agencies from our analysis.
We used fixed-effects regression models to estimate the relationships  among COPS expenditures, officers, and crime. Given that we included  agencies based on the completeness of their crime data in each year, and  agencies provided complete crime data in different numbers of years over  our 1990 through 2001 analysis period, our models used an unbalanced  panel approach. In all of our models, we expressed expenditures, officers,  and crime in per capita amounts. The fixed-effects models provide  estimates of the amount of change in our dependent variables—the per  capita sworn officer rate and the per capita crime rates—that can be  attributed to changes in the per capita COPS hiring grant expenditures,  controlling for other factors that could also contribute to changes in the  per capita sworn officer rate. Our models included agency and year fixed  effects to control for unobserved differences between agencies and  changes over time within agencies in factors that could contribute to  declines in crime. We introduced state-by-year fixed effects into our  regressions to control for factors occurring at the state level—such as  changes in incarceration or state sentencing practices—that could affect  crime rates. Further, we included in our models variables that classify  each agency in categories based upon their pre-1994 trends in the growth  of officers and crime. These growth cell variables allow us to make  comparisons between agencies that were similar in their pre-COPS  program trends but that varied in the timing and amount of COPS  expenditures. Finally, we included in our models measures of other  federal law enforcement grant programs that also provided funds to state  and local law enforcement agencies for hiring officers and other crime- prevention purposes. Specifically, we included measures of the per capita  expenditures on Local Law Enforcement Block Grants, which local  governments could use to hire law enforcement officers, pay overtime,  purchase equipment, as well as several other purposes. Because of data  limitations, we were unable to track amounts of the Edward Byrne  Memorial State and Local Law Enforcement Assistance (Byrne Formula  Grant Program) grants that went to local agencies. Byrne Formula Grant  funds could be used to provide for personnel, equipment, training,  technical assistance, and information systems, among other purposes. In  addition to the formula grant program, there was also a Byrne  discretionary grant program, and we included measures for these grants.
In appendix VI, we provide the details about the specific models that we  estimated and our methods for calculating elasticities of the relationship  between changes in officers and changes in crime rates.
section_title: Methods to Assess Changes in Policing Practices
paragraphs: To assess whether COPS funds contributed to changes in policing  practices, we analyzed data from the Policing Strategies and National  Evaluation of COPS surveys, two nationally representative surveys of local  law enforcement agencies that asked about the types of policing practices  that the agencies reported implementing in various years. In each survey,  chief executives or their designees were presented a list of policing  practices and asked to indicate whether their agency implemented the  practice. We classified items in the surveys into four categories of policing  practices corresponding to general approaches to policing identified in the  criminal justice literature: problem-solving practices, place-oriented  practices, community collaboration activities, and crime analysis  activities. Problem-solving practices call for police to focus on specific  problems and tailor their strategies to the identified problems. Place- oriented practices include attempts to identify the locations where crime  occurs repeatedly and to implement procedures to disrupt these  recurrences of crime. Community collaboration practices include  improving citizen feedback about crime problems and the effectiveness of  policing efforts to address these problems. Crime analysis includes the use  of tools such as geographic information systems to identify crime patterns.  These tools may help an agency support other practices for preventing  crime, such as problem-solving and place-oriented practices.
For each agency in a survey, we created a summary index of the number  of such practices that agencies reportedly implemented in the years in  which the surveys were administered. We then compared mean levels of  reported practices between groups of agencies that participated in the  COPS program and those that did not participate in the program.
We used the data from the Policing Strategies Survey to make pre- and  within-COPS program comparisons of changes in reported policing  practices in 1993 and in 1997. Levels of reported practices among agencies  that received COPS grants were compared with levels among agencies that  were not funded by COPS grants over this period. We used the National  Evaluation of COPS Survey to compare levels of practices in 1996 and  2000 between groups of agencies that received COPS grants and those  agencies that were not funded by COPS over this period. In appendix VII,  we provide additional details about the surveys and our methods for  analyzing the survey data.
To assess changes in reported practices in relation to participation in the  COPS program, we estimated separate regression models of the effects of  the receipt of a COPS grant and per capita COPS expenditures on changes  in reported policing practices, controlling for various characteristics of  agencies and underlying trends in the reported adoption of policing  practices.
To identify policing practices that may be effective in reducing crime, we  analyzed six studies that provided summaries of research on the  effectiveness of policing practices and activities on reducing crime. We  chose to review studies that reviewed research, rather than reviewing all  of the original studies themselves, because of the volume of studies that  have been conducted on the effectiveness of policing practices. (See app.  VII for a list of the studies that we reviewed and additional details on  policing practices and crime.)
section_title: Database Construction and Samples Used in Our Analyses
paragraphs: To construct our primary analysis database, which consisted of 12 years of  data from 1990 through 2001 for law enforcement agencies that reported at  least 1 complete year of crime data to the FBI’s Uniform Crime Reporting  Program, we obtained data from several sources and merge-matched  information from these various sources to the level of the local law  enforcement agency. The sources of data that we used to compile the  annual observations from 1990 through 2001 on local police departments  included:    Office of Justice Programs Financial Data—Annual data on the  obligation and expenditures on each grant awarded by OJP. Obligations  refer to the funds that are expected to be paid on a grant, and  expenditures refer to the grant funds that have been paid to a recipient.  Because OJP and the COPS Office share data on awards, the OJP data  also included COPS grant obligation and expenditure amounts. We  used data on grant obligation amounts to and annual amounts  expended by each recipient of a community-oriented policing (or  COPS) grant, and annual amounts of other federal local law  enforcement grants expended both by agencies that received COPS  funds and those that did not. We used information about place codes  and OJP vendors to link these data to our other sources.
The UCR—Annual data files on the number of crimes and sworn  officers reported by each agency to the UCR. The data on sworn  officers represent the reported number of full-time officers in each  agency on October 31 of each year. We analyzed the number of sworn  officers per 10,000 persons in the covered jurisdiction. We analyzed  data on the violent crimes of murder and non-negligent manslaughter,  forcible rape, robbery, and aggravated assault, and the property crimes  of burglary, larceny-theft, and motor vehicle theft. We analyzed the  crime rate per 100,000 persons in the covered jurisdiction for each type  of crime, as well as the rates for all index crimes, violent crimes, and  property crimes. We used the originating agency identifier (ORI)  variable and place codes to link crime and officer data to other data  sources.
Bureau of Economic Analysis (U.S. Department of Commerce)— Annual county-level estimates of per capita income and employment  for each year from 1990 through 2001. We included in our analysis of  officers, crime, and policing practices, measures of economic factors  that are related to crime, such as the employment-to-population ratio  and per capita income. We linked these data to agency-level data using  place codes. Local economic conditions within each county are applied  to each agency within a county.
National Center for Health Statistics (NCHS) and U.S. Census Bureau— Annual estimates of the United States resident population for each  county from 1990 through 2001. Data obtained include population  totals and population breakdowns by gender, race, and age. Under a  collaborative arrangement with the U.S. Census Bureau and with  support from the National Cancer Institute, NCHS prepared postcensal  population estimates for 2000 through 2001. The Census estimates of  county population from 1990 through 1999 are updated to take into  account these postcensal estimates. We included in our analysis of  officers, crime, and policing practices measures of demographic factors  that are related to crime, such as the percentage of total population in  the 15-to-24 age group—an age group associated with high crime  rates—and the racial composition of populations. We linked these data  to agency-level data using place codes.
Law Enforcement Agency Identifiers Crosswalk (Bureau of Justice  Statistics)—The crosswalk file provides geographic and other  identification information for each record included in either the  Federal Bureau of Investigation’s Uniform Crime Reporting Program  files or in the Bureau of Justice Statistics (BJS) Directory of Law  Enforcement Agencies (DLEA). The main variables each record  contains are the UCR originating agency identifier number, agency  name, mailing address, Census Bureau’s government identification  number, and Federal Information Processing Standards (FIPS) state,  county, and place codes. We utilized FIPS codes to merge records from  the crosswalk with OJP financial data and then used agency ORI codes  to merge the crosswalk and financial data with crime data from the  UCR.
subsections: section_title: Data Used in Our Analysis of Obligations and Expenditures
paragraphs: To report on COPS obligations and expenditures, we first analyzed the  amounts reported in OJP financial data before we merged the financial  information onto the agency-level crime records in the UCR. In the OJP  data, each record represents either an obligation or an expenditure  amount, and an agency appears in the database each time it has either an  obligation or an expenditure. The total amount of obligations for COPS  grants for the 1990- through 2001- period in the OJP data was $7.62 billion.
Second, we linked the OJP financial data to agency information in the BJS  crosswalk file. We used agency identifying information in the OJP financial  data—such as FIPS state, county, and place codes—to link OJP records  with agencies in the crosswalk file. This resulted in our identifying 13,332  agencies that had at least one record of an obligation in the OJP financial  data.  Of these, 10,680 (or 80 percent) received at least one COPS grant,  and among the agencies that received COPS grants, the total amount of  COPS obligations was $7.32 billion (or 96 percent of all COPS obligation  amounts).
Third, to describe the distribution of obligations relative to agency  population and crime, we selected agencies that reported complete crime  data—12 months of crime data within a given year—in at least 1 year from  1990 through 2001, and we merged their records onto the records of the  agencies for which we had OJP financial information. This last group  contained 11,187 agencies, and 8,819 (or 78.8 percent) of these agencies  received at least one COPS grant. The total amount of COPS obligations  among these agencies was $6.01 billion (or 79 percent of the total amount  of COPS obligations from 1994 through 2001).
section_title: Data Used in Our Analysis of Officers and Crime
paragraphs: To analyze the impacts of COPS expenditures on officers and crime, we  started with the UCR data and included in our samples agencies that met  specific criteria. First, we identified and included agencies that reported at  least 1 year of complete crime data—that is, 12 months of crime data in a  given year—to the UCR from 1990 through 2001, and we included agencies  only in the years in which they provided complete crime data.
Second, we excluded from our analysis agencies that the UCR classifies as  “zero-population” agencies. To avoid double counting of citizens within  geographic areas, the UCR program assigns population counts only to the  primary law enforcement agency within each jurisdiction. Consequently,  transit police, park police, university police, and similar agencies that are  contained within these jurisdictions are assigned a value of zero for  population. Because of the fact that jurisdictions among zero-population  agencies overlap with primary agencies, calculation of precise per capita  crime rates for these nonprimary agencies is problematic. Many state  police agencies also enforce laws among populations that are policed by  other local agencies, which also makes problematic calculating per capita  crime rates for state police agencies. Additionally, given that state police  agencies often have multiple substations in varied locations throughout  the state, the correct allocation of the proportion of federal dollars to each  substation is unknown. As a result, we excluded zero-population and state  police agencies from our analysis. Further, we included in our analysis  agencies whose crime records we were able to merge-match and link with  OJP financial data about COPS and other federal law enforcement grant  expenditures, as well as link with Bureau of Economic Analysis and  Census data on economic and population characteristics.
Overall, we identified 13,133 agencies that provided complete crime data  for at least 1 year from 1990 through 2001, that were not zero-population  agencies, and that we were able to link to our other data sources. For  example, in 1990, we found 10,160 agencies out of 17,608 that met our  conditions. These 10,160 agencies represented 57.7 percent of the agencies  that were included in the 1990 data that we obtained from the FBI, but  they contained 93.2 percent of the crimes included in the 1990 data. That  the agencies that we included in our sample in 1990 represented about 58  percent of all agencies but 93 percent of all crimes indicates that most of  the agencies that we omitted with our criterion of providing complete  crime data within a year were small agencies that reported relatively small  amounts of crime to the national total. For 2001, the 9,733 agencies that  reported complete crime data and were not zero-population agencies  represented 49.1 percent of all agencies in the UCR data in 2001 and  covered 94.8 percent of all crimes (table 3).
In our analysis of officers and crime, we further limited our sample to  agencies that covered populations serving 10,000 or more persons.  Complete crime data for agencies serving populations of fewer than 10,000  persons were missing for a large percentage of agencies, and we  determined that the data for these smaller agencies were unreliable for the  purposes of this report. In 1990, we found 4,051 of agencies serving  populations of 10,000 or more persons, which represented 23 percent of  the agencies included in the data that we received from the UCR for 1990  but also represented 86.8 percent of the crimes (table 3).
section_title: Data Used in Our Analysis of Reported Changes in Policing Practices
paragraphs: To assess changes in reported policing practices, we analyzed data from  two separate surveys of nationally representative samples of local law  enforcement agencies. The surveys asked key officials at agencies about  the types of policing practices that they reportedly used. Both surveys  consisted of two administrations or waves of observations on the agencies  in their respective samples. The first survey, the National Survey of  Community Policing Strategies (or Policing Strategies Survey), was  administered in 1993 and again in 1997. A total of 1,269 agencies in the  1993 and 1997 samples responded to both waves of the survey. We limited  our analysis to the 1,188 agencies that had complete data on each of the  policing practices items that we included in our analysis and that we were  able to link to our larger database on crime, officers, money, and  economic conditions. These agencies amounted to about 94 percent of the  agencies that responded to both waves of the survey. For comparability  with our analysis of the effects of COPS grants on officers and crime, we  limited our analysis to the sample of agencies that served jurisdictions  with populations of 10,000 or more persons.
The second survey, which we call the National Evaluation of COPS Survey,  was conducted by the National Opinion Research Center for the Urban  Institute in its national evaluation of the implementation of the COPS  program. Of the 1,270 agencies that responded to both the 1996 and 2000  administrations of the survey, we were able to link the data from 1,067  agencies to our larger database on crime, officers, money, and economic  conditions. We restricted our analysis to agencies that served jurisdictions  having populations of 10,000 or more persons, and we excluded from our  analysis state police agencies and other special police agencies. (See app.  VII for more information about the sample of agencies that we analyzed.)
section_title: Reliability and Validity of the Data That We Used
paragraphs: Prior to developing our database, we assessed the reliability of each data  source. To assess the reliability of the various data sources, we (1)  performed electronic testing for obvious errors in accuracy and  completeness; (2) reviewed related documentation, including data  dictionaries, codebooks, and published research reports that made use of  the data sources; and (3) worked closely with agency officials to identify  any data problems. When we found discrepancies (such as nonpopulated  fields or what appeared to be data entry errors) we brought them to the  agencies’ attention and worked with them to correct the discrepancies  before conducting our analyses. We determined that the data were  sufficiently reliable for the purposes of our report.
In our regression analysis of the effects of COPS expenditures on crime,  we use the UCR reported crime rates as our dependent variables. Crimes  reported to the UCR are those brought to the attention of law enforcement  agencies and subsequently reported to the UCR, or reported crimes.  Reported crimes are a subset of all crimes committed, which is the sum of  reported crimes plus crimes that are not reported to the police. Our  ultimate interest, however, lies in determining whether COPS  expenditures affected the crime rate for all crimes, whether or not they  were reported to the UCR. This raises issues related to analyzing reported  crimes to learn about all crimes.
Because data on all crimes—reported and unreported—committed within  local jurisdictions are unavailable in national data systems, we use the  data on reported crimes. The nature of the relationship between reported  crimes and all crimes therefore determines whether the results of our  analysis of COPS expenditures on reported crime would lead to biased  estimates of the effects of COPS expenditures on all crimes. Under certain  circumstances, it is possible that our analysis of the effects of COPS on the  reported crime rate could lead to overestimates of the effect of COPS on  the crime rate for all—reported plus unreported—crimes. This would lead  us to overstate the effect of COPS in reducing crime.
Several conditions could lead to overestimates of the effects of COPS  expenditures on reducing crime. If the reported crime rate and the crime  rate for all crimes diverge, we would attribute to COPS a larger reduction  in crime than is warranted. If these crime rates diverge, the reported crime  rate would either decline at a faster rate or increase at a slower rate than  the rate for all crimes, and our analysis of the effects of COPS on the  reported crime would reveal either larger declines or smaller increases  than would occur if we had data on the rate for all crimes. A divergence  between the reported crime rate and rate for all crimes could arise for  either or both of two reasons: Citizens do not report all of the crimes they  experience to the police, or the police do not record and send to the UCR  all of the crimes that citizens report to them.
To assess whether citizens decreased the rate at which they reported  crimes to the police, we reviewed data from the National Crime  Victimization Survey (NCVS). These data are drawn from a nationally  representative sample of households and are gathered independently of  the police agencies that report crime to the UCR. They therefore provide a  measure of crime that is independent of the reporting practices of police  agencies. Respondents in the NCVS are asked about their experiences as  victims of crimes. If respondents were victims of crime, they are asked if  they or others reported the criminal victimization to the police. Using the  NCVS data, it is possible to assess whether the rate at which citizens  report crimes to the police has changed over time. These data show that  during the 1990s, victims generally increased the rate at which they  reported crimes to the police. As figure 5 shows, the decline in violent  crime over the decade was steeper for all crimes reported in the survey  than for the violent crimes reported to the police. Consequently, because  the rates diverged rather than converged, victims’ practices of reporting of  crime to the police during the 1990s are not likely to lead us to  overestimate the effects of COPS grants on the crime rate.
For police recording practices to lead to overestimates of the effects of  COPS grants on crime, it would be necessary for the agencies that  received COPS grants to decrease the rate at which they recorded and  reported crimes to the UCR. Research on police recording practices  suggests that agencies are unlikely to underreport serious crimes, such as  murder, rape, robbery, and aggravated assault. Other studies found,  second, that as police agencies adopt computer technology and become  more sophisticated in recording crimes, they became more likely to  increase the rate at which they included all citizen-reported crimes to the  UCR. As COPS MORE grants provided funds for technology—such as  laptop computers in police cars—that would have increased the level of  sophistication within agencies, COPS grantee agencies would be more  likely to report a larger percentage of the crimes that citizens drew to their  attention. Consequently, changes in police reporting practices that stem  from COPS grants and lead to increases in police reporting of crimes to  the UCR are likely to lead us to underestimate the magnitude of effects of  COPS grants on reducing crime.
Two other conditions that could affect our estimates include the following:  (1) Criminals who commit the crimes that are not reported to the police  are unresponsive to the effects of COPS expenditures, and (2) as the  number of police increase, the number of reported crimes increases,  independently of the true crime rate.
If criminals who commit crimes that go unreported to the police are  unresponsive to police presence, then we would overestimate the effects  of COPS on crime only if criminals changed their behavior to victimize  more persons who would be unlikely to report crimes to the police. This  appears to be an unlikely occurrence, as the NCVS data show a  convergence between the total number of criminal victimizations,  especially for violent crimes, and the number of crimes reported to the  police.
Second, if the size of the police force systematically affects the willingness  of victims to report crime to the police or a police department’s likelihood  of recording and reporting to the UCR crime victims’ reports, then these  changes could lead to biased estimates of the impact on the crime rate.  However, if changes in reporting behaviors occurred as the result of the  COPS program, the likely impact on our estimates of the effect of COPS  grants on crime through their effects on the number of officers is that we  would underestimate the effects of the grants on crime.
Given these considerations, our analysis of the effects of COPS  expenditures on crime is more likely to underestimate than overestimate  the effect of COPS funds on changes in the true crime rate.
section_title: Appendix II: Background on the COPS Program and Studies of the Impacts of COPS Grants on Crime
paragraphs: Established in October 1994 by the Attorney General to implement the  administration of community policing grants under the Violent Crime  Control and Law Enforcement Act (VCCLEA) of 1994, the Office of  Community Oriented Policing Services announced its first grant program  in November 1994. Prior to its establishment, in December 1993 the  Department of Justice began making community policing grants to state  and local law enforcement agencies that the COPS Office monitored. In  1993, DOJ awarded community policing grants under the Police Hiring  Supplement Program, which was established by the Supplemental  Appropriations Act of 1993 (P.L. 103-50 (1993)). The grants made under  this program were funded by DOJ’s Bureau of Justice Assistance.
Two goals of the COPS Office were to advance community policing by  providing funding for 100,000 community policing officers and to promote  the practice of community policing, an approach to policing that involves  the cooperation of law enforcement and the community in identifying and  developing solutions to crime problems. COPS attempted to achieve these  goals by providing law enforcement agencies with grants to hire officers,  purchase equipment, and implement innovative policing practices.
subsections: section_title: COPS and Other Local Law Enforcement Grants Distributed throughout the 1990s
paragraphs: According to our analysis of Office of Justice Programs data, from 1994  through 2001, the COPS Office distributed more than $7.6 billion in grants.  Grants were made in a variety of grant program funding categories. Table  2 in appendix I contains more information about these funding categories.  The largest amount of COPS grant funds obligated—about $4.8 billion, or  64 percent of the total—was in the form of hiring grants. These grants  required agencies to hire new officers and at the same time to indicate the  types of community policing strategies that they intended to implement.  Hiring grants paid a maximum of $75,000 per officer over a 3-year period  (or at most 75 percent of an officer’s salary) and generally required that  local agencies cover the remaining salary and benefits with state or local  funds. Hiring programs authorized under VCCLEA and administered by the  COPS Office included the Phase I program, which funded qualified  applicants who had applied for the Police Hiring Supplement but were  denied because of the limited funds available; COPS AHEAD (Accelerated  Hiring, Education, and Deployment) for municipalities with populations  50,000 and above; and COPS FAST (Funding Accelerated for Smaller  Towns) for towns with populations below 50,000. In June 1995, Phase I,  COPS AHEAD, and COPS FAST were replaced by the Universal Hiring  Program.
The next largest grant category was the Making Officer Redeployment  Effective (MORE) grant program, which provided funds to law  enforcement agencies to purchase equipment and hire civilians, with the  goal of expanding the amount of time spent on community policing. COPS  obligated more than $1.3 billion—or about 17 percent of total  obligations—as MORE grants. Additional COPS grant programs provided  funds for specific innovations in policing. For example, the Distressed  Neighborhoods Pilot Project grants provided funds to communities with  high levels of crime or economic distress to hire officers and implement a  variety of strategies to improve public safety, and the Methamphetamine  Initiative provided funds to state and local agencies to support a variety of  enforcement, intervention, and prevention efforts to combat the  methamphetamine problem. About $418 million—or about 5.5 percent of  the total—was obligated under these innovative grant programs. The  COPS Office also provided grants for a variety of other purposes, including  funding to meet the community policing training needs of officers and  representatives of communities and local governments (through a network  of Regional Community Policing Institutes), and grants to law enforcement  agencies to hire and train school resource officers to help prevent school  violence and improve school and student safety (the COPS in Schools  Program). Over $1 billion—or about 14 percent of total obligations—was  obligated among these miscellaneous grant programs.
In each year, the COPS Office was required to distribute half of the grant  funds to agencies in communities whose populations exceeded 150,000  persons and half of the grant funds to agencies in communities with  populations of 150,000 or fewer persons.
During the 1990s, other federal law enforcement grant programs also  provided funds to state and local law enforcement agencies for hiring  officers and other crime prevention purposes. The Edward Byrne  Memorial State and Local Law Enforcement Assistance (Byrne Formula  Grant Program) was a variable pass-through grant program administered  by the Bureau of Justice Assistance (BJA).  According to our analysis of  data that we obtained from OJP, from 1990 through 2001, the Byrne  Formula Grant Program distributed between $415 million and $520 million  in grants. States were required to pass through to local jurisdictions  amounts of funding based upon a variable pass-through formula. Byrne  Formula Grant funds could be used to provide for personnel, equipment,  training, technical assistance, and information systems, among other  purposes. According to an evaluation of the Byrne formula grant program,  about 40 percent of Byrne subgrant funds—the amounts passed through  the states to local jurisdictions—were for multijurisdictional task forces.  In addition to the formula grant program, there also was a Byrne  discretionary grant program. According to an official at the Bureau of  Justice Statistics (BJS), a large percentage of the Byrne discretionary  funds were targeted for specific programs.
The Local Law Enforcement Block Grant (LLEBG) Program was also  administered by BJA. The LLEBG grant funds amounted to about an  average of $475 million per year from 1996 through 2000. According to BJS  officials, these funds were allocated by a formula based upon violent  crimes as reported in FBI’s crime index. LLEBG funds were available to  local governments for hiring law enforcement officers, paying overtime,  purchasing equipment, as well as several other purposes. According to the  Urban Institute’s evaluation of the implementation of the COPS program,  agencies that received COPS grants reported using both Byrne and LLEBG  funds to support their transitions to community policing.
Additional grant programs that provided funds to local law enforcement  agencies included the Juvenile Accountability Incentive Block Grants,  Weed and Seed Grants, and several Office on Violence Against Women  grants, according to a BJS official.
section_title: Debates over whether the COPS Office Met Its Goals for Officers and Promoted Community Policing
paragraphs: The amount of COPS funding was more than sufficient to fund the federal  portion for 100,000 officers. According to the Attorney General’s report,  from 1994 through 2000, the COPS Office awarded more than 30,000 grants  to over 12,000 law enforcement agencies and funded more than 105,000  community policing officers. However, a research report by the Heritage  Foundation questioned how effective the COPS Office had been in putting  100,000 officers on the street. The study analyzed trends in the number of  officers and concluded that the COPS program had not added 100,000  additional officers above historic trends. In its review of the COPS Office’s  performance for the fiscal year 2004 budget, the Office for Management  and Budget (OMB) indicated that by 2002, COPS grants funding was  sufficient for almost 117,000 officers, a number that exceeded the  program’s original commitment to fund 100,000 officers. At the same  time, OMB acknowledged that fewer than 90,000 officers had been hired or  redeployed to the street. OMB reported that the COPS Office counted  88,028 COPS-funded officers on duty as of August 2002—or about 75  percent of funded officers. In their report of October 2002 on the COPS  program, researchers at the Urban Institute updated earlier estimates of  COPS-funded officers. They projected that over the years from 1994  through 2005, COPS-funded officers would add between 93,400 and  102,700 officers to the nation’s communities on a temporary basis, but that  not all of these officers would be available for service at any one point in  time. They further estimated that the permanent impact of COPS, after  taking into account postgrant attrition of officers and civilians, would be  between 69,100 and 92,200 officers.
In addition to promoting the hiring of officers, the COPS Office sought to  promote community policing. COPS hiring grant applications asked  agencies to report the types of practices that they planned to implement  with their grants, such as identifying crime problems by looking at records  of crime trends and analyzing repeat calls for service, working with other  public agencies to solve disorder problems, locating offices or stations  within neighborhoods, and collaborating with community residents by  increasing officer contact with citizens and improving citizen feedback. In  2000, the Attorney General reported that 87 percent of the country was  served by departments that practiced community policing.
Studies that have addressed the extent to which the COPS Office grants  caused the spread of community policing suggest that COPS grants  accelerated the adoption of these practices but did not launch the spread  of community policing. The Police Foundation’s study of community  policing practices during 1993—1 year before the COPS Office began  making grants—indicated that the practice of community policing was  fairly widespread, especially in larger police departments. The Police  Foundation researcher reported that 47 percent of the agencies surveyed  in 1993 reported that they either were in the process of adopting or had  adopted community policing, but that 86 percent of municipal agencies  with more than 100 sworn personnel were either in the process of  implementing or had implemented community policing. In their evaluation  of the implementation of the COPS program, Urban Institute researchers  credited COPS with promoting community policing, but the researchers  concluded that COPS funds seemed to have fueled movements that were  already accelerating rather than have caused the acceleration. In a later  report, they pointed out that for large agencies, the problem-solving  practices that they examined were already widespread by 1995, and almost  no COPS grantees reported adopting problem-solving practices for the  first time between 1998 and 2000.
Some of the types of practices that agencies planned to implement with  their COPS grants correspond with approaches to policing that recent  reviews of policing practice suggest are effective in preventing crime.   For example, our review of policing practices indicates that problem- solving policing and place-oriented policing practices—such as those in  which officers attempt to identify the locations where crime occurs  repeatedly and to implement procedures to affect crime—are among the  types of practices that research has demonstrated to be effective in  preventing crime. These practices were among the types that agencies  could implement with their COPS grants.
section_title: Debates about COPS’ Contribution to the Decline in Crime in the 1990s
paragraphs: In 2000, the Attorney General reported that COPS-funded officers helped  to reduce crime. The Attorney General’s report to Congress asserted that  the drop in crime that occurred after 1994 was more than would have been  expected in the absence of the passage of VCCLEA and the creation of the  COPS Office. As evidence of the impact of COPS grants on crime, it  proffered the inverse relationship between increases in the per agency  number of police officers and decreases in the per agency levels of violent  crimes.
Studies of the impact of COPS grants on crime that attempted to take into  account factors other than just the underlying trends in crime were  released in 2001. A COPS Office-funded study examined the impact of  COPS grants on local crime rates in over 6,000 communities from 1995  through 1999. Analyzing changes in crime rates in communities that had  received COPS grants, the study concluded that COPS hiring grants were  effective in reducing crime and that COPS grants for innovative policing  practices had larger impacts on reducing violent and property crime than  did other types of COPS grants. However, a study released by the Heritage  Foundation, which was based upon the analysis of county-level data, was  unable to replicate the findings of the COPS-funded study. Specifically,  the Heritage study found no effect of COPS hiring grants on crime rates,  but it found that grants for specific problems—such as gangs, domestic  violence, and illegal use of firearms by youth—were associated with  reductions in crime. In addition, our review of the COPS-funded study  found that its methodological limitations were such that the study’s results  should be viewed as inconclusive.
The inconclusiveness of the findings of studies was reflected in OMB’s  assessment of the performance of the COPS program. According to OMB,  although the COPS Office used evaluation studies to assess whether its  grants had an impact on crime, the results of the findings were  inconclusive, and OMB rated the COPS program as “Results Not  Demonstrated” in 2004 using its Program Assessment Rating Tool (PART).
section_title: Issues in Assessing the Contribution of COPS Grants to the Decline in Crime in the 1990s
paragraphs: Assessing whether COPS funds contributed to the decline in crime during  the 1990s is complicated by many factors. Nationwide, the decline in crime  began before 1993, which was before the COPS program made its first  grants. According to the FBI’s data on index crimes—the violent crimes of  murder, rape, aggravated assault, and robbery and the property crimes of  burglary, larceny, and motor vehicle theft—the decline in the overall index  crime rate, as well as the property and violent crime rates started as early  as 1991 or 1992 (fig. 6).
As COPS grants cannot be the cause of the start of the decline in crime  rates, the other factors that led to the decline in the crime rate could also  have affected the decline in crime during the period that the COPS Office  made its grants. Factors such as a downturn in handgun violence, the  expansion of imprisonment, a steady decline in adult violence, changes in  drug markets, and expanding economic opportunities are among those  suggested as related to the decline in crime—especially violent crime—in  the 1990s. To the extent that these factors also are correlated with the  disbursement of COPS funds, this increases the challenges involved in  isolating the effects of COPS grants.
Other federal funds for local law enforcement could also have contributed  to expanding the number of police officers and contributed to declines in  crime. If the distribution of non-COPS funds such as LLEBG and Byrne  grants is correlated with that of COPS funds, and if research does not take  these funds into account, a study could attribute some of the effect on  crime of these other grant funds to COPS grants.
COPS grants were distributed in ways that make rigorous evaluations of  their causal impacts difficult to implement. Receipt of a COPS grant was  not randomly assigned; therefore, it is difficult to determine whether the  agencies that received grants are the same ones that, in the absence of the  grant, would have experienced reductions in crime. The amount of funding  certain agencies receive may also relate to the agency’s ability to combat  crime. For example, certain police chiefs may be more capable than others  at acquiring funds and also more up-to-date on policing methods.  This  underlying capacity of an agency to organize policing, rather than the  receipt of a particular grant, would then be the cause of a crime decline as  opposed to a particular grant. Additionally, COPS grants were fairly  widespread throughout police departments and the nation as a whole. This  distribution of grants leaves relatively few unfunded agencies to serve as  comparison groups against which to assess the performance of the  agencies that received COPS grants. The roughly 12,000 agencies that the  former Attorney General reported received COPS grants by 2000 represent  about 61 percent of the agencies that reported crime to the Uniform Crime  Reports.
The mechanisms by which COPS funds could affect crime have not been  explicitly examined. For example, the two prior studies that we cited did  not examine whether COPS grants potentially affect crime through  changes in police officers or through changes in policing practices, both of  which may have been affected by COPS funds. Additional officers may  affect crime by increasing police presence, by increasing arrests that lead  to incapacitation of offenders, or by deterring offenders by increasing the  likelihood of capture. Changes in policing practices toward problem- solving or place-oriented practices that focus police resources on  recurring crime problems could also lead to reductions in crime.
Appropriate methodologies from research on crime have been developed  to address issues that could confound efforts to assess the impacts of  COPS grants on crime rates. For example, if COPS grants are to affect  crime through their impacts on the number of officers, then isolating the  effects of increases in officers on crime presents a challenge in assessing  the direction of the relationship between officers and crime. If additional  officers are hired in response to increases in crime rates, then it could  appear that crime causes officers. Alternatively, if additional officers lead  to reductions in crime below the levels that they would have been without  the officers, then it would appear that officers caused changes in crime. To  isolate the causal effect of COPS grants, researchers employ the use of  instruments for causal variables. One suggestion in the research literature  for an instrument for police officers is COPS hiring grants. To the extent  that COPS hiring grants buy only officers, COPS hiring grants can be used  as an instrument for the actual number of police officers and therefore be  used to estimate the relationship between crime and police officers in a  way that takes into account the possibility of this simultaneous  relationship.
Second, particular forms of statistical models take advantage of  information about the variation in the amount and timing of COPS grants  among agencies to assess how changes in the number of sworn officers  and crime rates are associated with these two sources of variation. These  fixed-effects regression models use a panel of data—or repeated  observations on the same units, in this case, police agencies, over several  time periods—to assess the effects of changes in the number of sworn  officers and crime rates that are associated with variation in the timing  and amount of COPS grant expenditures. These regression methods also  allow for the introduction of controls for unobserved preexisting  differences between units (agencies) and differences over time within  units. Incorporating each agency’s underlying trajectories (or growth rate  trends) in crime rates and sworn officers into the modeling of the effects  of COPS funds allow for explicit comparisons within groups of agencies  sharing similar trajectories, which helps to control for potential biases  associated with preexisting trends. By identifying and explicitly modeling  the mechanisms through which a program could have its effects—such as  COPS funds leading to increases in the number of officers and their effects  on crime—the possibility of a spurious relationship between inputs (such  as COPS funds) and outcomes (such as crime) can be minimized.
section_title: Appendix III: COPS Grant Obligation and Expenditure Patterns
paragraphs: This appendix addresses how COPS obligations were distributed among  local law enforcement agencies in relation to the populations they served  and the crimes in their jurisdictions. It also addresses how much of the  obligated amounts agencies spent. Specifically, it covers (1) the amount of  COPS obligations between 1994 and 2001, (2) the distribution of grant  funds to larger and smaller agencies relative to total index and violent  crimes, (3) the number of agencies in our sample that received COPS  grants, (4) the amounts of COPS expenditures, and (5) the amount of these  expenditures relative to total local law enforcement expenditures.
subsections: section_title: Smaller Agencies Received Larger Amounts of COPS Obligations per Crime than Did Larger Ones
paragraphs: Our analysis showed that from 1994 through 2001, COPS obligated more  than $7.32 billion to 10,680 agencies for which we were able to link OJP  financial data on COPS obligations to the records of law enforcement  agencies. As shown in table 4, about $4.7 billion (or 64 percent) of these  obligations were for hiring grants. Equipment and redeployment grants  made under the MORE category of grants amounted to about $1.2 billion  (or about 17 percent) of total obligations.
As shown in table 5, from 1994 through 2001, slightly more than half of the  COPS obligations in the sample of agencies for which we were able to link  OJP financial data to the records of agencies that reported crime and  population to the FBI’s Uniform Crime Reporting Program went to those  agencies serving populations of 150,000 or fewer persons and slightly less  than half went to those agencies serving populations of more than 150,000  persons, roughly consistent with the requirements of COPS authorizing  legislation.
The largest agencies—those serving populations of 150,000 or more  persons—accounted for more than half of all violent crimes reported to  the UCR. Specifically, in our sample, these agencies accounted for about  58 percent of all violent crimes reported in the UCR from 1994 through  2001. Their share of all violent crimes declined slightly from 60 percent  from 1994 through 1997 to 57 percent from 1998 through 2001. These  agencies received about 47 percent of all COPS obligations, a share that is  disproportionately small relative to their contribution to all violent crimes.  However, as shown in table 5, the amount of COPS obligations going to  agencies serving populations of 150,000 or fewer persons and those  serving populations of more than 150,000 persons was about equal to the  distribution of all index crimes occurring within these agencies.
Table 6 shows that law enforcement agencies serving the smallest  populations received the largest amounts of COPS obligations on a per  crime basis. For example, agencies serving populations of fewer than  10,000 persons received, on average, $1,573 per violent crime reported  from 1994 through 2001. By comparison, agencies serving populations of  more than 150,000 persons received $418 per reported violent crime.
subsections: section_title: Most Agencies Had Received Their First COPS Grant by 1996
paragraphs: As shown in table 7, of the 10,680 agencies included in our analysis, just  under half (49 percent) had received at least their first COPS grant by  1995, and 71 percent had received at least their first grant by 1996. Of the  9,845 agencies that received at least one COPS hiring grant, 53 percent had  received their first hiring grant by 1995, and 73 percent had done so by  1996.
We estimated that about 67 percent of the agencies that reported complete  crime data to the UCR for at least 1 year from 1990 through 2001 received  a COPS grant by 2001. The percentages of agencies that received COPS  grants varied by the size of agencies, as measured by the size of the  population in the jurisdictions served by the agencies. As table 8 shows, as  the population served by the agencies increased, the percentage of  agencies that received a COPS grant also increased. Among the largest  agencies—those serving populations of more than 150,000 persons—about  95 percent received a COPS grant. By comparison, among agencies serving  populations of fewer than 10,000 persons, about 61 percent in our sample  of agencies received at least one COPS grant.
section_title: Total COPS Expenditures and Per Capita Expenditures Peaked in 2000, and Smaller Agencies Spent More than Larger Ones on a Per Capita Basis
paragraphs: By 2001, agencies had drawn down about $5 billion in COPS funds (or  roughly 68 percent of all obligations awarded from 1994 through 2001). As  figure 7 shows, total COPS expenditures increased annually from 1994 to  2000. Total expenditures exceeded $900 million per year in each year from  1998 through 2001, and in 2000, they exceeded $1 billion. COPS hiring  grant expenditures totaled $3.5 billion (or roughly 70 percent of the  roughly $5 billion in hiring grant obligations made from 1994 through  2001). Hiring grant expenditures peaked in 1998—exceeding $690  million—and declined slightly in 1999 and 2000.
The number of agencies that spent COPS funds peaked in 1998 and  declined thereafter, as figure 8 shows. In 1998, more than 7,500 agencies  were spending COPS funds. However, by 2001, the number had fallen to  about 6,000.
COPS expenditures per population in the jurisdictions that spent funds— per capita expenditures—also increased as the total amount of COPS  expenditures increased. Total per capita COPS expenditures peaked in  2000 at $5.6 per person. Hiring grant expenditures per capita similarly  peaked at $4.8 per person in 2000. The per capita expenditure amounts  varied by size of agency, as smaller agencies generally spent more on a per  capita basis than did larger agencies. Agencies serving populations of  fewer than 10,000 persons spent about twice as much COPS grant monies  on a per capita basis than did the larger agencies. For example, per capita  COPS expenditures for agencies serving fewer than 10,000 persons  averaged $6.6 as compared with about $3.4 for agencies serving  populations of more than 150,000 persons.
section_title: COPS Expenditures Amounted to about 1 Percent of All Local Law Enforcement Expenditures
paragraphs: From 1994 through 2001, COPS expenditures amounted to about 1 percent  of total local expenditures for nationwide police services, based upon BJS  data on criminal justice expenditures and our analysis of OJP data on  COPS grant expenditures. From 1994 through 2001, total local  expenditures for police services increased from about $46 billion to $72  billion. During the years from 1998 through 2000, when COPS  expenditures neared and then exceeded $1 billion per year, the  contribution of COPS expenditures to local police expenditures increased  to about 1.5 percent of total local expenditures for police services.
section_title: Appendix IV: COPS Expenditures Led to Increases in Sworn Officers and Declines in Crime
paragraphs: This appendix addresses our second reporting objective, which has two  parts: determining the extent to which COPS grant expenditures  contributed to increases in the number of sworn officers in police  agencies, and determining the extent to which COPS grant expenditures  led to reductions in crime through their effects on sworn officers.
subsections: section_title: COPS Expenditures Led to Increases in Sworn Officers above Levels That Would Have Been Expected without Them and Were Responsible for about 88,000 Officer- Years
paragraphs: We found that COPS hiring grants were significantly related to increases in  sworn officers above levels that would have been expected without the  expenditures, after controlling for economic conditions in the counties in  which agencies were located, population composition, and preexisting  trends in agencies in the growth rate of sworn officers. Further, the effects  of COPS hiring grants were consistent across several different regression  models, including those that controlled for state-level factors that could  affect the size of local police forces—such as state-level differences in the  amount of funding provided to local departments. Overall, the parameter  estimates from our models indicate that each $25,000 in COPS hiring grant  expenditures was associated with roughly an additional 0.6 officers in any  given year. With the exception of MORE grants, no other types of COPS  grant expenditures were associated with increases in officers.
Using the results from our regression models, we calculated for each year  from 1994 through 2001 the number of sworn officers nationwide that  would have been on the street absent the COPS expenditures in each year.  The difference between this amount and the actual level of sworn officers  yielded the number of officers due to COPS expenditures in a given year.  The number of officers due to COPS increased from 84 in 1994 to 17,387 in  2000, and then declined to 12,226 in 2001 (table 9). The increase and  decrease in the number of officers due to COPS followed the pattern of  COPS expenditures, which peaked in 2000 and then declined (see fig. 7 in  app. III). Adding up the number of officers due to COPS in each year  across the years from 1994 through 2001, we arrive at a total of about  88,000 sworn officer-years due to COPS expenditures.
From 1997 through 2000, when COPS expenditures neared or exceeded $1  billion per year, we estimated that the expenditures led to increases in  sworn officers of between 2.4 percent and 2.9 percent above levels  expected without them. In years prior to 1997, and in 2001, when COPS  expenditures were lower, the percentage of officers due to COPS  expenditures were lower than occurred from 1997 through 2000.
An officer-year is the number of officers in a given year that were  associated with COPS expenditures. According to this measure, an  individual officer—or person—might be included in our counts of officers  due to COPS in several years. Therefore, our estimate of the total number  of officer-years arising from COPS expenditures is not equivalent to the  number of officers that the COPS Office reportedly funded, nor does it  represent an estimate of the total number of officers as a result of COPS  grants. For a given year, however, our estimate represents the number of  COPS-funded officers on the street. (For additional details on the methods  we used to estimate the effects of COPS expenditures on officers, see   app. VI.)
subsections: section_title: LLEBG Funds Also Contributed to Increases in Officer Strength
paragraphs: In addition to our findings of the effects of COPS expenditures on the level  of sworn officers, we found that Local Law Enforcement Block Grants  expenditures also contributed to increases in officers above levels  expected without them. Our finding about LLEBG grants effects on sworn  officers is consistent with interview and survey responses reported by  Urban Institute researchers in their evaluation of the implementation of  the COPS program. In their interviews with police chiefs, they found that  the chiefs reported that they used LLEBG to supplement COPS funds.  LLEBG grants could be used for a variety of purposes in addition to  funding officers.
section_title: COPS Expenditures Led to Reductions in Crime through Increases in Officers
paragraphs: Estimating the impact of COPS expenditures on changes in crime rates  through their effects on the number of sworn officers, we found that COPS  expenditures were associated with declines in crime rates for total,  violent, and property crimes, as compared with their baseline levels in  1993, the year prior to the distribution of COPS grants. The amounts of  decline in crime rates varied among crime types and across years. The  variation in the decline in crime rates in various crime types arose from  our estimates of the effects of changes in officers on crime rates, and the  variation over time within crime types arose from the variation in COPS  expenditures. For example, for the total crime rate, we found that the  impact of COPS peaked in 1998, as for that year, we estimated that COPS  led to a reduction in the total crime rate of almost 1.4 percent from the  level of crime in 1993. From 1999 and 2000, COPS expenditures of between  $920 million and about $1 billion led to reductions in the total crime rate of  about 1.3 percent, again, as compared with the 1993 level. In years prior to  1998 and in 2001, when COPS expenditures were lower than their levels in  1998 through 2000, the declines in total crime arising from COPS  expenditures also were less than 1.3 percent (table 10).
Similarly, for violent and property crimes, we found that the amount of  decline associated with COPS expenditures varied from year to year, and  for both of these crime categories, the largest decline in crime occurred  during 1998. COPS expenditures led to a decline in violent crime of almost  2.6 percent in 1998, compared with violent crime levels in 1993. For 1999  and 2000, COPS expenditures led to about a reduction of about 2.4 percent  in violent crime, from the 1993 level. For property crimes, the impact of  COPS expenditures from 1998 through 2000 was between 1.1 percent and  1.2 percent, as compared to the 1993 level (table 10).
Our estimates of the impact of COPS expenditures on crime through their  effects on the number of officers represent the effects of COPS  expenditures on crime net of the effects of other factors that we controlled  for in our model—including changes in economic conditions, population  composition, and pre-COPS program trends in police agencies’ growth rate  of sworn officers and growth rate in crime. By controlling for pre-COPS  program growth rates in officers and crime, we made comparisons  between agencies within population size categories that had similar  growth rates in officers and crime but which differed on the timing and  amount of COPS expenditures. In addition, through the use of state-by- year fixed effects, we controlled for state-level factors that could affect  crime rates, such as changes in sentencing policy or state incarceration.
As our estimates of the impact of COPS expenditures on crime come, in  part, from our estimates of the effects of changes in officers on crime, we  compared our estimates of the effect of changes in officers on changes in  crime with estimates of these effects that appear in recent research. We  found that each 1 percent increase in sworn officers was associated with  about a 0.4 percent decline in total crime, about a 0.8 percent decline in  violent crime, and a slightly less than 0.4 percent decline in property  crime. Our estimates of this relationship—the elasticity of crime with  respect to officers—is consistent with estimates that appear in recent  literature of the effects of changes in police officers on changes in crime  rates. Others report elasticities that are similar to ours. For example, in a  study that used COPS granted officers to estimate the effect of increases in  officers on crime, the authors reported an estimated elasticity for violent  crime of –0.99 (a 1 percent increase in officers led to a 0.99 percent decline  in violent crimes) and a property crime elasticity of –0.26. In another  paper that used electoral cycles to estimate the effect of increases in  officers on crime, the author provides a set of elasticities under different  model specifications. The elasticity for property crimes was calculated to  be about –0.3, and the elasticity for violent crimes was about –1.0. (See  app. VI for more information on the methods that we used to calculate our  elasticities and to estimate the impact of COPS expenditures on crime.)
subsections: section_title: Various Specifications of Our Regressions Yielded Consistent Findings about the Effect of COPS Expenditures on Crime
paragraphs: While we found that COPS expenditures were associated with reductions  in total crime and the violent and property crime categories, when we  examined the effects of COPS expenditures on specific types of index  crimes, we found significant reductions in murder, robbery, aggravated  assault, burglary, and motor vehicle theft. We found a negative association  between COPS expenditures and larceny, but this effect was not  statistically significant. Finally, we found a positive but statistically  insignificant association between COPS expenditures and rape. (See table  17 in app. VI.)
Additionally, for agencies that served populations of 10,000 or more  persons, we found that the effects of COPS expenditures on the total  crime rate were consistent across agencies that served populations of  varying sizes with the exception of agencies that served populations of  between 25,000 and 50,000 persons. The magnitude of the effects tended to  increase with the size of agencies, where agency size refers to the  population served by the agency. In general, as the size of agencies  increased, we found that the impact of COPS expenditures on the total  crime rate also increased. For agencies serving populations between  25,000 and 50,000, we observed a negative relationship between COPS  expenditures and crime.  However, the estimated effect was not  statistically significant. (See table 18 in app. VI.)
As there are uncertainties associated with formulated regression models,  and point estimates derived from a single regression model can give  misleading information, we estimated our regressions under different  assumptions about how COPS expenditures could affect crime. Under the  various models, we introduced lagged effects, nonlinear effects for COPS  hiring grants, and effects for the year of receipt of COPS grants—to test  whether the impact of COPS occurred in the years in which the money  was spent. From the various specifications, we estimated the elasticity of  crime with respect to officers. We found that the elasticity for total crimes  ranged from –0.41 to –0.95. The elasticity that we used to calculate the  impact of COPS on the decline in index crimes was –0.42, which is at the  lower end of the range of elasticities that we estimated. Therefore, under  assumptions different from the preferred specification about how COPS  expenditures are related to officers and crime, we would arrive at a larger  estimated impact of COPS on the decline in crime than we report above.  Also, under the varying assumptions about how COPS expenditures are  related to crime, we estimated elasticities of violent crimes with respect to  officers and elasticities of property crimes with respect to officers. For  violent crimes, the elasticities derived from these regressions ranged from  –0.76 to –1.8. The elasticity that we used to estimate the impact of COPS  on the decline in violent crimes was –0.8. This elasticity is at the lower end  of the range of elasticities that we estimated, which implies that the  impacts of COPS on violent crimes could be larger than the impacts that  we reported. For property crimes, the range of estimated elasticities was  from –0.35 to –0.80. (See table 20 in app. VI.)
In addition to our findings of the effects of COPS expenditures on crime,  we found that LLEBG expenditures were consistently associated with  declines in total crime rates and declines in the murder, rape, robbery,  aggravated assault, burglary, and larceny crime rates. Only for motor  vehicle theft did we not find a significant effect of LLEBG expenditures.  However, because LLEBG grant funds are related to the levels of violent  crime occurring within a jurisdiction, the relationship between LLEBG  expenditures and crime may be one of bidirectional causality. By this, we  mean because LLEBG grant amounts were determined in part on the levels  of violent crime, violent crime in a community can be construed as a cause  of LLEBG grants in addition to an effect of having received them. (See  table 17 in app. VI.)
section_title: Factors other than COPS Expenditures Contributed Larger Amounts to the Reduction in Crimes, but COPS Contribution Was in Line with COPS Expenditures
paragraphs: The decline in crimes attributable to COPS expenditures accounted for at  most about 10 percent of the total drop in crime from 1993 to 1998, and  about 5 percent of the drop from 1993 to 2000. Therefore, various factors  other than COPS expenditures were responsible for the majority of the  total decline in crime during the 1990s. While in our regression models of  the effects of COPS funds on crime, we were able to control for the effects  of many factors that could be related to the decline in crime, we did not  attempt to estimate the amount that each of these factors individually had  contributed to the overall drop in crime. Rather, by isolating the amount  by which crime rates declined because of COPS and comparing that  amount with the total decline in crime from our 1993 baseline year, we  calculated COPS contribution to the overall decline in crime. The amount  of the total drop in crime not associated with COPS expenditures reflects  the amount due to factors other than COPS.
While COPS’ contributions to the decline in crime rates did not account  for the majority of the total drop in crime rates, the amounts of declines in  crime rates attributable to COPS were on the same order of magnitude as  were COPS expenditures’ contributions to local law enforcement  expenditures for police. From 1994 through 2001, COPS expenditures  amounted to slightly more than 1 percent of total local expenditures for  police services nationwide. As we found and reported, COPS expenditures  were responsible for about a 1.4 percent decline in the total crime rate.
section_title: Appendix V: COPS Expenditures Associated with Policing Practices That Crime Literature Indicates Are Effective in Preventing Crime
paragraphs: This appendix addresses our third reporting objective: determining the  extent to which COPS grant expenditures during the 1990s were  associated with police departments adopting policing activities or  practices that the crime literature indicates could contribute to reductions  in crime. Specifically, it describes the results of our analyses of the  relationships between COPS grant expenditures and changes in policing  practices reported in two surveys of local law enforcement agencies, and it  summarizes our assessment of studies that conducted systematic reviews  of research on the effectiveness of various policing practices. Our analysis  of the first of the two surveys of policing practices compares changes in  reported policing practices between 1993 and 1997, that is, prior to the  distribution of COPS grants and after many COPS grants had been  distributed. In our analysis of the second survey, we compare changes  from 1996 to 2000, or during the implementation COPS program. In  addition, we provide a limited summary of our analysis of systematic  reviews of evaluations of policing practices that could contribute to  reductions in crime. (See app. VII for the details related to our  methodology for analyzing policing practices.)
subsections: section_title: Comparisons of Pre- and Within-COPS Grant Program Levels of Reported Policing Practices Show That COPS Grantee Agencies Reported Larger Increases than Non-COPS Agencies
paragraphs: Prior to the implementation of COPS grants, many local law enforcement  agencies had adopted a number of problem-solving, place-oriented, crime  analysis, and community collaboration policing practices. Problem-solving  practices refer to efforts by the police to focus on specific problems and  tailor their strategies to the identified problems. Place-oriented practices  include attempts to identify the locations where crime repeatedly occurs  and to implement procedures to disrupt these recurrences of crime. Crime  analysis includes the use of tools such as geographic information systems  to identify crime patterns. Community collaboration includes attempts to  improve or enhance citizen feedback about crime problems and the  effectiveness of policing efforts to address them.
Our analysis of the Policing Strategies Survey data for 1993—the year  before COPS grants were distributed—indicates that surveyed agencies  that received a COPS grant between 1994 and 1997 reported higher mean  levels of the above policing practices than agencies that did not receive a  COPS grant between 1994 and 1997. For example, in 1993, the mean  number of all practices reported by grantee agencies was about 13 out of a  possible 38 practices, while the mean number of all practices reported by  nongrantee agencies was about 11 practices. However, among the  agencies that received a COPS grant between 1994 and 1997, there were  larger increases in the mean level of all reported practices between 1993  and 1997 except for those related to crime analysis. COPS grantee  agencies reported in 1997 an increase of about 3.5 practices overall, as  compared with a mean increase of less than 2 practices by the agencies  that did not receive COPS grants during this period. The largest  differences between COPS grantees and nongrantee agencies in the  reported increase in practices occurred for the problem-solving and place- oriented practices (table 11).
From a series of regression models of the effects of COPS grants on  changes in policing practices, we found that both the receipt of a COPS  grant, and the amount of per capita COPS expenditures by agencies were  associated with increases in the levels of reported policing practices  between 1993 and 1997. Our regressions control for the underlying trend in  the reported use of policing practices, for differences in agency  characteristics that could be associated with increases in reported levels  of policing practices—such as the size of the jurisdiction—and changes in  the economic and social characteristics of the county in which the agency  was located. We estimated separate regressions of the effect of the receipt  of a COPS grant and of the cumulative per capita amount of COPS  expenditures on the levels of reported policing practices.
Our regression models for estimating the effects of receipt of a COPS grant  on the change in police practices between 1993 and 1997 show that  agencies that received at least one COPS grant had significantly larger  changes in the overall number of practices than did agencies that did not  receive a COPS grant during this period. Specifically, according to our  analysis of the survey data, the average number of practices increased by  2.9 over this period, and the receipt of a COPS grant accounted for 1.8 of  this reported increase. Further, when we examined our results from  separate regressions for the different categories of practices, we found  that receipt of a COPS grant was associated with significant increases in  reported levels of problem-solving and place-oriented practices, but was  not related to changes in community collaboration or crime analysis  practices. (See app. VII for details.)
Our regression models further show that changes in practices were also  associated with the cumulative amount of per capita spending on COPS  grants. All other things being equal, a $1 increase in per capita spending  was associated with an increase of 0.23 policing practices. As we found for  the effects of the receipt of a grant on changes in police practices, these  regressions also showed that the level of per capita spending on COPS  grants was significantly associated with increases in problem-solving and  place-oriented practices. However, per capita spending on COPS grants  was also associated with increases in crime analysis practices. (See app.  VII for details.)
subsections: section_title: The Effects of COPS Grants on Agencies’ Reported Increases in Policing Practices Differed across Agencies Serving Populations of Different Sizes
paragraphs: Receipt of a COPS grant was associated with increases in the overall  adoption of policing practices among agencies serving populations of  different sizes. Regardless of the size of populations served, agencies that  received COPS grants adopted almost twice as many practices between  1993 and 1997 as agencies that did not receive COPS grants. However, in  both years, agencies serving larger populations also reported higher mean  levels of policing practices (table 12 and fig. 9).
Our regressions of the effect of COPS expenditures on changes in reported  levels of policing practices between 1993 and 1997, indicate, however, that  the effects of receiving a COPS grant were larger in agencies in  jurisdictions serving fewer than 50,000 persons and in jurisdictions serving  more than 150,000 persons, than in agencies in jurisdictions serving  populations of between 50,000 and 150,000 persons.
section_title: Reported Levels of Policing Practices among COPS Grantees Did Not Increase Overall from 1996 to 2000
paragraphs: Our analysis of the National Evaluation of COPS Survey data on policing  practices in 1996 and in 2000 also showed that agencies that received  COPS grants reported larger increases in the mean level of policing  practices than did non-COPS grantee agencies, but that the effects were  not statistically significant. The findings suggest that there was no  continued overall increase in reported policing practices in the period  from 1996 to 2000.
Regardless of when agencies received COPS grants and made COPS  expenditures, we found that COPS grantee agencies reported larger  increases in policing practices between 1996 and 2000 than did the  agencies that did not have COPS grants in these years. For example, for  the agencies that received their first COPS grant in 1996 or before, the  average increase in reported use of policing practices from 1996 to 2000  was about 21 percent, and for the agencies that made COPS grant  expenditures after 1996, the average increase in reported use of policing  practices was about 17 percent. By contrast, for the agencies that had not  made any COPS grant expenditures by 2000, there was about a 0.2 percent  decrease in the reported use of policing practices from 1996 to 2000, and  for the agencies that did not make any COPS grant expenditures after  1996, there was about a 3 percent increase in the reported use of policing  practices from 1996 to 2000 (table 13).
Although we observed larger average increases in reported policing  practices among agencies that spent COPS grant funds than among  agencies that did not spend COPS grant funds, when we controlled for  underlying trends in the reported adoption of policing practices and  agency characteristics, we found that changes in per capita COPS  expenditures made between the period preceding wave 1 of the survey  (1994 through 1996) and the period following wave 1 of the survey (1997  through 2000) were not associated with changes in reported overall  policing practices between 1996 and 2000 (app. VII). This suggests that  there was no continued overall increase in reported policing practices in  the period from 1996 to 2000, as a function of COPS grant expenditures.
section_title: Crime Literature Provides Evidence for Effectiveness of Some Policing Practices
paragraphs: Our analysis of six systematic reviews of evaluations of the effectiveness  of various policing practices in preventing crime indicates that the current  evidence ranges from moderate to strong that problem-oriented policing  practices and place-oriented practices are either effective or promising as  strategies for addressing crime problems. For example, problem-oriented  approaches that focus on criminogenic substances such as guns and drugs  appear to be effective in reducing both violent and property crimes. And  hot spots approaches—place-oriented approaches that temporarily apply  police resources to discrete locations where crime is concentrated at  much higher rates than occur jurisdictionwide—have also been found to  be effective in reducing crime. However, the magnitudes of the effects of  these interventions are difficult to estimate, especially on citywide crime  rates, as the interventions that were reviewed as effective generally were  concentrated in comparatively small places. Further, the enduring nature  of these interventions is not fully understood. It is not known, for example,  how long the effects of a problem- or place-oriented intervention persist.  In addition, some of the reviews point out that research designs  undertaken to date make it difficult to disentangle the effects of problem- oriented policing from hot spots policing. There is suggestive, but limited,  evidence that the combination of these practices may be more effective in  preventing or reducing crime than any one strategy alone.
In contrast to the findings on problem-oriented and place-oriented policing  practices, there is little evidence in the literature for the effectiveness of  community collaboration practices—such as increasing foot patrol,  establishing community partnerships, and encouraging citizen  involvement—in reducing or preventing crime.
section_title: Appendix VI: Methods Used to Estimate the Effects of COPS Funds on Officers and Crime
paragraphs: In this appendix, we describe the methods we used to address our  reporting objective regarding the impacts of the COPS funds on officers  and crime: determining (1) the extent to which COPS grant expenditures  contributed to increases in the number of sworn officers in police agencies  in the 1990s and (2) the extent to which COPS expenditures contributed to  declines in crime in the 1990s through their effects, if any, on officers.
subsections: section_title: Prior Literature on the Relationship between Officers and Crime Addresses Issues Relating to Estimating the Effects of COPS Funds on Crime
paragraphs: In examining the effect of COPS funds on crime, we estimate the impacts  of the funds on crime through their impacts on officers. The effect of  police on crime has a theoretical basis in the economics literature.  Economic models posit that criminals weigh the gains from criminal  activity against its costs—the possibility of arrest and incarceration.  Anything that increases the probability of arrest, such as additional police,  will thus deter criminal activity; we might call this the deterrence effect. A  second effect stems from arrests directly. If criminals are arrested and  incarcerated, they will not be able to commit street crimes; we might call  this the incapacitation effect.
The relationship between police and crime has been studied empirically,  with mixed results. Several reviews of research that investigated this  relationship have reported that a minority of papers find a significant  negative relationship between increases in the number of officers and  crime. However, these reviews also point out that many of the studies  have methodological flaws. In a report to Congress on what works in  crime prevention, Lawrence Sherman and others drew upon a limited body  of research that addressed the methodological concerns and concluded  that increases in the number of police officers work to prevent crime.
One of the major methodological issues associated with estimating the  relationship between police officers and crime is the issue of reverse  causality. This issue revolves around determining how to disentangle the  relationship between the number of police officers and crime, as  municipalities having higher crime rates generally also have more officers.  For example, Detroit has twice as many police per capita as Omaha and  four times the violent crime rate, but it would be incorrect to conclude  that the additional officers in Detroit were the cause of its higher crime  rate than Omaha’s. By simply comparing a municipality’s police force and  crime rate to those in other municipalities, one would incorrectly infer  that Detroit’s higher crime rate was caused by its additional police  officers.
Repeated observations on crime and police in a locality lead to a more  robust research design by controlling for the time-invariant differences in  rates of crime and police between areas. This is done by introducing fixed  effects into regression models. Using this approach, the question that the  analysis attempts to address becomes: Do we see the crime rate fall as the  number of police rises? By controlling for the “baseline” crime rates in  different areas, some researchers have estimated a negative relationship  between police and crime.
However, if the rise in the number of police in a locality is a response to  increasing crime rates, including fixed effects does not resolve the issue of  reverse causality raised by the Detroit example. A next step is to introduce  an instrument—for example, a variable that affects the size of the police  force but that, given this size, does not affect crime. In one study, the  researcher made use of the fact that the size of a police force increases  before an election. If the only way that crime is affected by the election is  through the number of police, then this approach can be used to estimate  the relationship between crime and police. In this study, the researcher  found that crime fell in several index categories before an election.
A series of more recent papers that used instruments found a negative  relationship between police and crime. Two studies used an increase in  police presence because of a terrorist alert and showed declines in  nonterrorist-related crimes within a single city. In a study of Buenos Aires,  the researchers found that police stationed in response to a terrorist threat  on Jewish centers caused a decline in automobile theft. In another paper,  the researchers showed that crime fell in Washington, D.C., on days when  the Department of Homeland Security increased the terror alert level. At  the national level, researchers at the University of Maryland used the  number of police officers granted through the COPS program as an  instrument for the actual number of police and estimated negative  relationships between increases in police officers and crime.
section_title: Our Approach to Estimating the Effects of COPS Expenditures on Officers and Crime
paragraphs: We adopted a two-stage approach to estimating the effects of COPS  expenditures on crime. Much as the University of Maryland researchers  did, we used COPS funds as a source of variation to explain officers.  However, while the University of Maryland researchers used officers  granted by COPS funds, we used COPS expenditure amounts—the actual  COPS dollars spent by agencies in given years—as the source of variation.  We began with an analysis of the “first stage” and tested whether COPS  funds had an effect on the number of officers. To the extent that hiring  funds affected the number of police but did not affect crime in any other  way, these funds would be a valid instrument for estimating the effect of  officers on crime. We then estimated the “reduced form,” or the  relationship between COPS expenditures and crime. Using parameters  estimated from these regressions, we are able to calculate the relationship  between police and crime.
This approach has limitations, however. For example, we learn very little  about how agencies operate. If agencies were to use the additional officers  to employ different police tactics, and were able to reduce crime, we  would be unable to say whether it was the increase in officer numbers or  tactics that was the true cause of the decrease. Thus, we would be unable  to contribute to the question of whether increases in officer strength are  either necessary or sufficient to reduce crime, without a change in police  tactics.
A second concern is that agencies that were more likely to take initiative  in applying for and receiving COPS grants might be those that were also  more effective in preventing crime.  These agencies might also be those  that achieved larger or more rapid declines in crime.  If this were the case,  we might incorrectly associate declines in crime with COPS grant  expenditures because of other possible factors.  To assess this potential,  we estimated a regression that predicted whether an agency spent COPS  funds in a given year from 1994 through 2001 based on demographic  characteristics, economic conditions, and lagged property and violent  crime rates.  From the regressions, we predicted the probability of  spending COPS grant funds—or the propensity of agencies to spend COPS  funds.  Whether or not an agency actually spent COPS funds, it received a  propensity score, based upon the values of its characteristics in the model  that predicated the probability of spending COPS funds.  Agencies that  actually spent COPS funds can then be compared to similar agencies— those with similar propensity scores—that did not spend COPS funds.  We  grouped agencies into five categories based on their propensity scores.   Within each of these five categories, we compared the patterns of violent  crime rates and property crime rates between the agencies that spent  COPS funds and those that did not spend them.  Our analysis showed that  within these groupings of agencies having similar propensity scores, the  agencies that actually spent COPS funds generally had larger declines in  crime rates than did those that did not spend COPS funds.
Another question is whether a drop in a specific crime type, such as  automobile theft, in a certain locality is a net gain for society as a whole.  For example, the rationality of criminals may lead them to respond to an  increase in the number of police by moving to an area with fewer police or  switching to a different type of crime. In addition, there is the possibility  that an increase in the number of police increases the reporting rate of  crimes, and not the crimes themselves. This possibility, however, would  lead us to underestimate the effects of COPS funds on crime, as discussed  in appendix I.
subsections: section_title: Model of the Effect of COPS Expenditures on the Number of Police Officers
paragraphs: Our main specification estimated the effect of COPS funds on officers,  using the following control variables:  (1) POLICEit = βHIREit+ βMOREit+ βINNOVit+ βMISCit + βBYRNEDISit +  βLLEBGit + βNONCOPSit + γXit + α+ α + αst + (quartile of prior growth  rates) * (population stratification) * year    POLICEit is the dependent variable, the sworn officers per 10,000 in  population in agency i in year t;    HIREit is the amount of money paid in Hiring grants; and   MOREit are COPS MORE grants; INNOVit are COPS grants for  innovative policing, and MISCit refers to the remaining types of COPS  grants; all are expressed as expenditure in per capita amounts.
BYRNEDISit are Byrne discretionary grant expenditures, LLEBGit are  LLEBG grant amounts, and NONCOPSit are all other federal non-COPS  law enforcement grants; all are expressed in per capita amounts. We  introduce these variables to control for other federal funds.
Xit contains a number of demographic and economic control variables,  including local employment rates, per capita income, and population  composition variables that measured the percentage of population 15  to 24 years old and the percentage of the population that was nonwhite.  The economic and demographic controls were measured at the level of  the county within which a particular agency was located.  The  parameters for these variables are represented by γ.
We included state-by-year fixed effects—represented by αst—to correct for  changes in crime policy at the state level, such as changes in the number  incarcerated and changes in sentencing policy.  We included agency fixed  effects—represented by α—to capture time invariant differences across  agencies, and time fixed effects—represented by α—to capture changes  affecting the entire nation.
Because of how the money was distributed, there may be some concern  that our estimate of the effect of the COPS money on officers is biased.  For example, it might be that agencies that received a disproportionate  share of the money relative to their populations had the benefit of  preexisting positive growth of numbers of officers, in addition to possible  declines in crime. If the trends continued, we might be incorrectly  associating increases in officers or decreases in crime with the amount of  COPS money received, rather than these preexisting trends.
To address this concern, we separated the agencies into four groups,  based on the growth rate in both officers and crime during 1990–1993,  when the COPS program was introduced. We constructed each  combination of these groups, producing 16 cells. These cells were then  “interacted” with each year and four population categories, for a total of  768 effects. In essence, each agency was compared with another agency  that had a similar “trajectory” of crime and officers in the pre-COPS  period. These growth trends are represented by the (quartile of prior  growth rates) expression in equation (1).
Finally, to obtain estimates of the effects of COPS expenditures on officers  relative to the average person in the United States, we estimated weighted  regressions where the weights were the population served by an agency.
section_title: Model of the Effect of COPS Expenditures on Crime
paragraphs: As with our methodology in estimating the effect of COPS funds on  officers, we estimate the effect of COPS funds on crime. Our main  specification used the following controls in the following equation:  (2) CRIMEit = µHIREit + µMISCit + µ + δ + δst + (quartile of prior growth  rates) * (population stratification) * year  The independent variables are identical to those defined for equation (1).  The dependent variable (CRIMEit) is the UCR total—or index—crime rate.  We also estimate separate equations for the crime rates of components of  the crime index: murder and non-negligent manslaughter, forcible rape,  robbery, aggravated assault, burglary, larceny theft, and motor vehicle  theft. Again, the parameters of interest are µstate-times-year fixed effects; and we also include the pre-1993 growth rate  variables.
section_title: The Implied Relationship between Police Officers and Crime
paragraphs: Unlike the other COPS grant types, COPS hiring grants were to be used  specifically for hiring officers. Consequently, variation in the number of  officers coming from COPS hiring grants should be unrelated to other  changes in police expenditures. In this sense, it may be a valid instrument  for officers.
Using the coefficients of officers in equations (1) and (2), we calculated an  estimate of the change in crime with respect to change in officers: (µ/β and β / β/CRIME and CRIMEquadratic term for COPS hiring grant expenditures provides a test for  nonlinear effects of COPS hiring grants on crime. This specification  examines whether the effects of officers on crime diminish as the number  of officers rises above certain levels.
section_title: Data Used in Our Analysis
paragraphs: We use data on 4,247 police agencies that reported complete crime (12  months of crime) in any year and that served populations of 10,000 or  more persons. These agencies represented about 23 percent of the  agencies that appeared in the UCR data that we received from the FBI.  However, they also covered more than 86 percent of the crimes and they  represented about 77 percent of the population in the UCR data that we  received. Because of concerns about data quality, we restricted our sample  to agencies that met these criteria of complete crime reporters and serving  populations larger than 10,000 persons. Across years, the number of  agencies that met these conditions varies, so our panel of data is  unbalanced. We used grant expenditure data from the OJP financial data,  which we linked to the crime and officer records of agencies. We included  county level demographic and economic data from the Census Bureau, the  National Center for Health Statistics, and the Bureau of Economic  Analysis. (See app. I for more information regarding the construction of  the dataset.)
Table 15 provides the means and standard deviations of the variables  included in the regression models.  As shown in the table, the per capita  expenditures derived from COPS hiring grants exceeded the per capita  amounts from other federal grants.
section_title: Explanation of the Results of Our Analysis
paragraphs: In this section, we discuss our regression analyses and describe how we  arrived at the results that are discussed in this report.
subsections: section_title: The Effect of COPS Expenditures on the Number of Police Officers
paragraphs: To arrive at the effects of COPS expenditures on officers, we estimated  specifications for equation (1), as shown in table 16. With only the fixed  effects, the models explain more than 90 percent of the variation in officer  strength. In specification 1, we added only the COPS hiring grant  expenditures per capita to the model that contained only the fixed effects.  The effects of hiring grants are significant at the 1 percent level, and the  coefficient indicates that an additional dollar of hiring grant expenditures  per capita changes the officer rate (measured per 10,000 persons) by 0.317.  In specifications 2 through 5, we introduce various combinations of the  growth rate cells, demographic and economic conditions, and the other  grant types. Across specifications 2 through 5, the estimated coefficient on  the hiring grant variable remains fairly consistent, ranging from 0.227 in  specification 5 to 0.261 in specification 3, where the interpretation of the  coefficient is the effect of a $1 increase in per capita COPS hiring grant on  the per 10,000 person rate of officers. Specification 5 presents our  preferred specification, in that it includes all of the relevant controls.  Using the coefficient on COPS hiring grant expenditures from  specification 5, we calculate the effect of $25,000 in COPS hiring grant  expenditures in a given year to produce roughly 0.6 additional officers in a  given year. Finally, in addition to the COPS hiring grant expenditures,  COPS MORE and LLEBG grant expenditures also consistently predict  officer strength, as indicated by the MORE and LLEBG parameter  estimates in specifications 2 through 5.
section_title: Effect of COPS Expenditures on Crime
paragraphs: Our reduced-form estimates of the effects of COPS expenditures on crime,  the result of our estimating equation (2) appear in table 17. This first  column (labeled “Officers”) repeats the results from specification 5 of  table 16. The other columns of table 17 show the parameter estimates for  the effects of hiring grants and outside funds on the crime rate for index  crimes and separately for type of index crime (except for arson). With the  exception of rape, COPS hiring grant expenditures per capita have a  negative effect on index crime rates and the crime rate for each type of  index crime. Further, while the direction of the effect of the hiring grant  variable on the larceny rate is negative, the effect is not significant at the 5  percent level. LLEBG expenditures have a negative and significant effect  on all crime types. The other grant fund types have a negative effect on  some crime types.
We estimated the effect of COPS hiring grant expenditures on index  crimes to be -29.19. In other words, $1 in COPS hiring grant expenditures  per capita translates into a reduction of almost 30 index crimes per  100,000 people.
section_title: The Effects of Different Population Sizes across Agencies
paragraphs: Given the variation in per capita COPS expenditures that occurred across  agencies serving populations of different sizes, we explored whether  COPS hiring grants had different effects on crime rates based on the size  of the population served by agencies. We stratified agencies into four  population size groups: those serving populations of between 10,000 and  25,000 persons; between 25,000 and 50,000 persons; between 50,000 and  150,000 persons; and more than 150,000 persons. We found that the effect  of the hiring grant was consistent across all population categories less  than 150,000, but insignificant in the population category of more than  150,000 persons. We found that negative effect of COPS hiring grants on  index crime rates ran across all population size categories. However, the  effects of hiring grants were largest in the 50,000 to 150,000 population  category, and insignificant in the 25,000 to 50,000 population category  (table 18).
section_title: Calculations of the Elasticity of Crime with Respect to Officers
paragraphs: As COPS hiring grants were to be used only to hire officers, we explored  their use as an instrument to predict the effect of officers on crime.  Assuming that COPS grants were used in that way, our preferred  specification from our regressions crime on COPS hiring grants and other  outside funds would produce estimates of the elasticity of crime with  respect to officers that are shown in table 19.
To assess the degree to which the elasticities that we calculated were in  line with those appearing in the economics of crime literature, we  compared our elasticities with those estimated by Evans and Owens  (2004), Levitt (1997), Levitt (2002), and Klick and Tabarrok (2005). Our  estimates are in line with those in the literature (table 19).
In addition, Evans and Owens report aggregate point elasticities for violent  and property crimes of –0.99 and –0.26, respectively, and Levitt reports  aggregate point elasticities for violent and property crimes of –0.44 and   –0.50, respectively.  Our aggregate elasticities for violent and property  crimes fall between these two sets of estimated point elasticities.
Equations (1) and (2) depend on certain assumptions about the way that  COPS hiring grant expenditures and other outside funds affect officers and  crime. For example, the specifications reported previously only allow the  effect of the federal funds to affect crime contemporaneously. However, it  may take a certain amount of time for the expenditures to have an effect  on either officers or crime, as it may take a certain amount of time for new  officers to become fully acclimated to a department, or to become  proficient in their duties. To explore the robustness of our findings under  varying assumptions about how COPS hiring grant expenditures could  affect officers and crime, we recalculated our elasticities after estimating  our regressions under the specifications outlined previously in table 20.  We report the elasticities that we calculated from these various regression  models (in the last three rows of the table). The elasticities for index  crimes range from –0.41 to –0.95; those for violent crimes range from –0.76  to –1.8; and those for property crimes range from –0.35 to –0.8. The  elasticities that we report in our results all fall at the lower end of the  range of elasticities that we estimated.
section_title: Estimating the Net Number of Officers Paid for by COPS Expenditures
paragraphs: We used our regression results to derive estimates of the net number of  officers paid for by COPS grant expenditures separately for each year. By  net number of officers, we refer to the increase in the number of officers  on the street attributable to COPS net of attrition. For example, if at the  beginning of a year, there were 100 officers on the street, while during a  year COPS grants were responsible for hiring 10 officers and 5 officers left  the force, the net number of officers due to COPS would be 5.
To obtain the total number of officer-years due to COPS expenditures, we  summed the number of officers across years. Table 21 presents the  estimated number of officers that COPS expenditures funds paid for in  each year. In column 1 we present the actual number of per capita officers  used in our regressions that generated the results in table 21. Not shown in  the table, but used in the calculation of the number of officers due to  COPS expenditures are the per capita amounts of COPS expenditures,  including COPS hiring, MORE, innovative, and miscellaneous grant  expenditures. Column 2 presents our estimate of what the per capita  number of officers would have been absent the COPS expenditures.  Columns 3 and 4 show the number of officers per capita and the  percentage of officers per capita explained by COPS expenditures.  Column 5 presents our estimates of the number of officers in each year in  the sample of agencies that we analyzed that were explained by COPS  expenditures. To arrive at the number of officers in the United States due  to COPS expenditures, we weighted the numbers in column 5 up to the  U.S. population total (in column 6). On the basis of this analysis, in year  2000, for example, when they peaked, the COPS expenditures per capita  were responsible for about 2.9 percent of the net increase in officers in the  United States, or more than 17,000 officers. Across all years, we estimate  that COPS was responsible for an increase of about 88,000 officer-years  during the years from 1994 through 2001.
section_title: Estimating the Number of Crimes Reduced by COPS Expenditures
paragraphs: On the basis of our analysis of the increase in officers attributable to COPS  expenditures, we estimated the amount of crime that could be attributable  to COPS, given the estimated effect of COPS expenditures on officers. On  the basis of our analysis of the number of officers due to COPS  expenditures and our estimated elasticities of crime with respect to  officers, we can estimate the number of crimes associated with COPS  expenditures through the increase in officers attributable to these  expenditures. In table 22, we show our calculations of the decline in crime  attributable to COPS for each year, compared with the 1993 levels of  crime, the pre-COPS baseline year.
Columns 1 through 3 of table 22 give the average crime rates per 100,000  persons in the agencies in our sample. Columns 4 through 6 give the  percentage change from 1993 in crime rates for each category of crime.  Columns 7 though 9 report data on officers. Column 7 reports the growth  in the officer rate from 1993 due to the change in COPS expenditures.  Column 8 presents the growth (from column 7) as a percentage change  from 1993. Columns 9 through 11 provide estimates of the percentage  change in crime rates from 1993 using the elasticities shown in table 22.  Finally, columns 12 through 14 provide the estimated amount of change in  crime rates from 1993 that arise from COPS expenditures.
section_title: Appendix VII: Methods Used to Assess Policing Practices
paragraphs: Our objective in assessing policing practices was to determine the extent  to which COPS grant expenditures were associated with police  departments’ adoption of policing activities or practices that may have  contributed to reduction in crime during the 1990s. To determine whether  COPS grants were associated with changes in policing practices, we  analyzed data from two national surveys of local law enforcement  agencies on the policing practices that they reportedly implemented in  various years from 1993 to 2000. In addition, we analyzed systematic  reviews of research on the effectiveness of policing practices in preventing  crime.
subsections: section_title: Methods to Address Changes in Policing Practices
paragraphs: To address whether COPS grants were associated with changes in policing  practices that may be associated with preventing crime, we analyzed data  from the two administrations of the Policing Strategies Survey (in 1993  and 1997) and two of the four administrations of the National Evaluation  of COPS Program Survey (in 1996 and 2000). Because the purposes of the  surveys differed, each used different samples of agencies (with some  agencies appearing in both surveys). The Policing Strategies Survey drew a  sample representative of all municipal police, county police, and county  sheriff agencies in the United States with patrol functions and with more  than five sworn officers in 1992, and the National Evaluation of COPS  Program Survey drew a sample that was representative of all law  enforcement agencies believed to be in existence in the United States that  had received, or were eligible to receive a COPS grant. Each survey  provided respondents in police agencies with lists of items that identified  specific types of policing practices, and respondents were asked whether  they had implemented each of the practices on the list. Survey responses  were obtained from knowledgeable officials within each agency, such as  the police chief or the chief’s designee. The number of items related to  policing practices differed between the two surveys.
We classified items in the surveys into four categories of policing practices  corresponding to general approaches to policing identified in the criminal  justice literature: problem-solving practices, place-oriented practices,  community collaboration activities, and crime analysis activities. Problem- solving practices call for police to focus on specific problems and tailor  their strategies to the identified problems. Place-oriented practices include  attempts to identify the locations where crime occurs repeatedly and to  implement procedures to disrupt these recurrences of crime. Community  collaboration practices include improving citizen feedback about crime  problems and the effectiveness of policing efforts to address these  problems. Crime analysis includes the use of tools such as geographic  information systems to identify crime patterns. These tools may help an  agency support other practices for preventing crime, such as problem- solving and place-oriented practices.
Three social science analysts with research experience in criminal justice  independently reviewed the list of policing practice items in each survey  and placed each item in one of the four categories or determined that the  item did not fit in any of the four categories. Following initial  classification, the analysts met to discuss and address any inconsistencies  in their classification of items.
After classifying practices, we created an index to represent the total  number of problem-solving, place-oriented, community collaboration, and  crime analysis practices, and we gave each agency that responded to both  waves of a survey a score equal to the number of these practices that the  agency reportedly implemented in the survey years. We also identified, for  each agency, the number of practices in each of the four categories.
We then analyzed the levels and changes in reported practices within each  survey. Our analysis focused on the differences in levels of practices  reported by agencies that received COPS grants and those that did not  receive them. To assess the influence of COPS grant expenditures on  reported practices, we analyzed changes in reported practices as a  function of the per capita amounts of COPS dollars spent by agencies. For  agencies that did not receive COPS grants, we set their per capita COPS  expenditure amounts to zero.
A limitation of our analysis is that the surveys did not ask explicitly about  the extent to which each listed practice was implemented by law  enforcement agencies. Thus agencies that report that they had  implemented a specific practice may vary considerably, from sporadic use  of the practice among a subset of officers in the agency to more frequent  use of the practice throughout the agency.
subsections: section_title: Characteristics and Analysis of the Policing Strategies Survey
paragraphs: The Policing Strategies Survey was administered in 1993 and again in 1997.  The Police Foundation administered the 1993 wave of the survey, and ORC  Macro International, Inc. and the Police Executive Research Forum  administered the 1997 wave of the survey. The sampling frame for both  the 1993 and 1997 waves consisted of 11,824 local police and sheriffs’  departments listed in the Law Enforcement Sector portion of the 1992  Justice Agency list developed by the U.S. Bureau of the Census. In  constructing the sampling frame, state police departments, special police  agencies, agencies that did not perform patrol functions, and agencies  with fewer than five sworn personnel were excluded from the larger list of  all law enforcement agencies. A total of 2,337 police and sheriffs’  departments were selected to be in the main sample for the 1993 survey,  and surveys were mailed to 2,314 of them after 23 agencies were found to  be out of scope before the surveys were mailed. Follow-up mailings and  facsimile reminders were sent to nonrespondents. The overall response  rate for the 1993 survey was 71.3 percent. All of the agencies in the first  sample were then selected for participation in the 1997 survey. The survey  employed a multiphased data collection approach, using postal mail for  the first phase, followed by facsimile reminders, a second mailing, and  computer-assisted telephone interviewing for nonrespondents. The  response rate for the 1997 survey was 74.7 percent. A total of 1,269  agencies were present in both the 1993 and 1997 surveys. The sample was  a stratified random sample with probability of inclusion varying by the  number of sworn personnel (5-9; 10-49; 50-99; and 100 or more sworn  personnel).
We identified agencies in the Policing Strategies Survey that responded to  both waves of the survey and had complete data on each of the policing  practices items, and of these, we were able to link the data from 1,188  agencies to our larger database on crime, officers, money, and economic  conditions. For comparability with the analyses of the effects of funding  on officers and crime, we limited our analysis to those agencies serving  jurisdictions with populations of 10,000 or more persons. This resulted in  usable data on 1,003 agencies.
We used the Policing Strategies Survey data to compare reported changes  in the types and levels of policing practices that occurred during the COPS  program with pre-COPS levels of practices. The analyses reported in this  appendix are weighted to adjust for the sample design effects. The findings  are generalizable to all municipal police agencies, county police agencies,  and county sheriff agencies in the United States with patrol functions and  serving jurisdictions with populations of 10,000 or more persons.
We used 38 items on policing practices from the Policing Strategies  Survey. We combined 12 practices pertaining to increasing officer contact  with citizens and improving citizen feedback into a community  collaboration index. We used 6 items on the crime analysis units within  police departments to create our index of crime analysis. We combined 8  practices pertaining to increasing enforcement activity or place  management in buildings, neighborhoods, or other specific places into an  index of place-oriented practices. And we compiled the data on 12 items  that reflected organizational efforts to reduce or interrupt recurring  mechanisms that may encourage crime into a problem-solving practices  index. The classification of items from the Policing Strategies Survey into  our four indexes of types of policing practices is shown in table 23.
The Policing Strategies Survey provided us with an opportunity to assess  changes in reported policing practices using a pre-COPS grant and within- COPS grant program framework. The 1993 administration of this survey  occurred several months prior to the distribution of the first COPS grants,  while the 1997 administration occurred after COPS grants had been made  to about 75 percent of the agencies in the sample. To implement the pre- within examination of the effects of COPS grants on policing practices, we  first compared the levels of practices in 1993 and 1997 between the group  of agencies that had received a COPS grant by 1997 and the group that had  not received a COPS grant by 1997.
Second, we estimated separate regressions of the effect of the receipt of a  COPS grant and of the cumulative per capita amount of COPS  expenditures on the levels of reported policing practices. To assess the  extent to which COPS grant expenditures were associated with changes in  reported policing practices, we estimated regressions of the changes in  reported policing practices that occurred within agencies as a function of  the cumulative per capita amount of COPS grant expenditures that they  made during the years from 1994 through 1997. We used two-factor fixed- effects regression techniques, which allowed us to control for unobserved  characteristics of agencies and underlying trends in the adoption of  policing practices. We also controlled for economic conditions and  population changes in the localities in which the agencies were located. In  addition, we used weighted regressions to address nonresponse patterns  and the probability with which the original sampling units were drawn.
Our regression equations show that both the receipt of a COPS grant and  the amount of per capita COPS expenditures by agencies were associated  with increases in the levels of reported policing practices between 1993  and 1997. Agencies that received at least one COPS grant had significantly  larger changes in the overall number of practices than did agencies that  did not receive a COPS grant during this period. Specifically, of the  roughly 2.9 average increase in the number of practices reported by  agencies over this period, the receipt of a COPS grant accounted for 1.8 of  the increase in the reported increase in practices. Further, when we  examined our results from separate regressions for the different  categories of practices, we found that receipt of a COPS grant was  associated with significant increases in reported levels of problem-solving  and place-oriented practices, but was not related to changes in community  collaboration or crime-analysis practices (table 24).
Our regression models further show that changes in practices were also  associated with the cumulative amount of per capita spending on COPS  grants. All other things being equal, a $1 increase in per capita spending  was associated with an increase of 0.23 policing practices. As we found for  the effects of the receipt of a grant on changes in police practices, these  regressions also showed that the level of per capita spending on COPS  grants was significantly associated with increases in problem-solving and  place-oriented practices. However, per capita spending on COPS grants  was also significantly associated with increases in crime analysis  practices.
section_title: Characteristics and Analysis of the National Evaluation of COPS Survey
paragraphs: The National Evaluation of COPS Survey was conducted by the National  Opinion Research Center for the Urban Institute in its national evaluation  of the implementation of the COPS program. The sampling frame for the  survey consisted of 20,894 law enforcement agencies believed to be in  existence between June 1993 and June 1997 who had either received a  COPS grant during 1995 or appeared to be potentially eligible for funding  but remained unfunded through 1995. The list of COPS grantees was  obtained from applicant records from the grants management database  from the COPS Office, and included those agencies that had been funded  from the following programs: FAST, AHEAD, Universal Hiring Program,  and MORE. The list of potentially eligible grantees was derived from the  FBI’s UCR and National Crime Information Center data files. The sampling  frame was stratified by COPS grantee status (Not Funded, FAST or  AHEAD, Universal Hiring Program (UHP), MORE), and by population  (jurisdictions with populations of fewer than 50,000 persons and those  with populations of 50,000 or more persons), and agencies in each stratum  were sampled at a different rate in order to select a representative sample  of law enforcement agencies. A total of 2,098 agencies were selected to be  in the sample.
Telephone interviews with agency representatives were conducted in 1996  (wave 1) and 2000 (wave 4). A total of 1,471 agencies responded to wave 1  of the survey in 1996, for a 77 percent response rate. In 2000, all wave 1  respondents were recontacted, and interviews were completed with 1,270,  or 86 percent, of the target agencies.
We were able to link the data from 1,067 of the agencies that responded to  both of these waves of the survey to our larger database on crime, officers,  money, and economic conditions. For comparability with the analyses of  the effects of funding on officers and crime, we excluded from our  analysis state police agencies, and other “special” police agencies, as well  as law enforcement agencies serving jurisdictions with populations of  fewer than 10,000 persons. This resulted in usable data on 724 agencies.
We used the National Evaluation of COPS Survey to compare levels of  practices in 1996 and 2000 between groups of agencies that received COPS  grants and those agencies that were not funded by COPS over this period,  and to assess changes in reported practices in relation to per capita COPS  expenditures. The analyses reported in this appendix are weighted to  adjust for nonresponse and the multiple counting of agencies that received  more than one COPS grant. The findings are generalizable to all law  enforcement agencies in the United States serving jurisdictions with  populations of 10,000 or more persons.
We used 19 items on policing practices from the National Evaluation of  COPS Survey, and we classified these items into the same 4 categories of  practices as we did with the Policing Strategies Survey data (table 25).  However, because of the shortage of items covering place-oriented  practices, for analysis purposes we combined these 3 items with the 7  problem-solving items into one index of problem solving and place  oriented practices.
Unlike the Policing Strategies Survey, which provided a pre-COPS and a  within-COPS measure of policing practices, both observations (in 1996 and  2000) on policing practices in the National Evaluation of COPS Survey  occurred while the COPS program was making grants. This complicates  our analysis, as in 1996 there were agencies that had already received and  spent COPS funds, and to the extent that COPS expenditures were  associated with the adoption of policing practices, the level of such  practices that they reported in 1996 would reflect their experiences with  COPS grants. Some of these agencies continued to spend COPS funds  throughout the years from 1996 through 2000.  However, some of the  agencies that spent COPS funds in 1996 ceased to spend them during the  intervening years before 2000. A third group of agencies consists of those  that had not received their first COPS grant in 1996 but had received a  grant before 2000. This third group is analogous to our group of agencies  that received COPS grants in the Policing Strategies survey, with the  exception that while members of this group received their first COPS grant  after the first administration of the National Evaluation survey in 1996,  their practices in 1996 could have been influenced by the COPS program  indirectly. A final group of agencies is those that did not receive a COPS  grant before the 1996 administration of the survey or during the years from  1997 through 2000.
Because the effects of experience with COPS grants before and after 1996  could differ, we chose to make two types of comparisons. First, we  examined the mean changes in policing practices from 1996 to 2000 for  each of the following groups of agencies: (1) agencies that made  expenditures on COPS grants in 1994 through 1996, (2) agencies that made  expenditures on a COPS grant in 1997 through 2000, (3) agencies that  made no expenditures on a COPS grant after 1996, and (4) agencies that  made no expenditures on a COPS grant in 1994 through 2000. These mean  comparisons allowed us to see whether changes in practices were  associated with receipt of a grant in either the early period of the program  (through 1996) or when the program was more fully implemented (1997  through 2000).
We then examined whether the level of COPS expenditures between the  two administrations of the survey were associated with changes in  practices between 1996 and 2000 by regressing the change in practices on  the change in cumulative per capita COPS expenditures between the  period preceding wave 1 of the survey (1994 through 1996) and the period  following wave 1 of the survey (1997 through 2000). As with the Policing  Strategies Survey, we used two-factor fixed-effects regression techniques,  which allowed us to control for unobserved characteristics of agencies  and underlying trends in the adoption of policing practices. We also  controlled for economic conditions and population changes in the  localities in which the agencies were located. In addition, we used  weighted regression to address the complex design of the National  Evaluation of COPS Survey. We estimated separate regressions of the  effect of the receipt of a COPS grant and of the cumulative per capita  amount of COPS expenditures on the levels of reported policing practices.
There were no significant differences in the overall adoption of policing  practices associated with changes in per capita spending on COPS grants  (table 26).
section_title: Methods to Review Policing Practices
paragraphs: To determine whether the certain types of policing practices may be  effective in reducing crime, we analyzed systematic reviews of research  studies on the effectiveness of policing practices.
subsections: section_title: How We Selected Studies
paragraphs: We identified six studies that provided summaries of research on the  effectiveness of policing practices on reducing crime. We chose to review  studies that reviewed research, rather than reviewing all of the original  studies themselves, because of the volume of studies that have been  conducted on the effectiveness of policing practices. We reviewed the  following studies:    Braga, Anthony. “Effects of Hot Spots Policing on Crime,” Annals,  AAPSS, vol. 578 (November 2001), pp. 104-125.
Eck, John. “Preventing Crime at Places” in Sherman, L., et al. (eds.)
Preventing Crime: What Works, What Doesn’t, What’s Promising: A  Report to the United States Congress. Washington, D.C.: National  Institute of Justice, 1998.
Eck, John, and Edward Maguire. “Have Changes in Policing Reduced  Violent Crime? An Assessment of the Evidence.” in Blumstein, A., and  J. Wallman, eds., The Crime Drop in America. United Kingdom:   Cambridge University Press, 2000.
Sherman, Lawrence. “Policing for Crime Prevention,” in Sherman, L., et  al. (eds.) Preventing Crime: What Works, What Doesn’t, What’s  Promising: A Report to the United States Congress. Washington, D.C.:  National Institute of Justice, 1998.
Skogan, Wesley, and Kathleen Frydl. “The Effectiveness of Police  Activities in Reducing Crime, Disorder, and Fear,” in Skogan, W., and K.  Frydl, (eds.) Fairness and Effectiveness in Policing: The Evidence,  Washington, D.C.: National Academies Press, pp. 217-251, 2004.
Weisburd, David, and John Eck. “What Can Police Do to Reduce Crime,  Disorder, and Fear?” Annals, AAPSS, Vol. 593 (November 2004), pp. 42- 65.
A limitation of basing our work on reviews is that we did not assess the  original studies, but rather we relied on the descriptions and assessments  as provided by the authors of the reviews. Sometimes the reviews did not  cite specific information about the strength of the methodology of the  underlying studies that were included in reviews.
section_title: How We Reviewed Studies
paragraphs: We developed a data collection instrument to capture systematically  information about the methodologies of the reviews, the types of policing  practices reviewed, findings about each type of practice, and the  reviewers’ conclusions about the effectiveness of a particular practice or  group of practices in reducing crime. Each research review was read and  coded by a social science analyst who had training and experience in  reviewing research methodologies. This analyst recorded, for each  practice discussed in the research review, (1) the types of crimes against  which the practices were used (e.g., all crimes, violent crimes, property  crimes, disorder); (2) whether the practice was generally effective in  reducing crime, had no effect in reducing crime, or the impact was  ambiguous; (3) whether there was displacement of crimes away from the  areas where the practices were used; and (4) whether there were negative  effects of the practices (e.g., complaints against the police or the diversion  of resources from other policing activities). A second, similarly trained  analyst then read the reviews and verified the accuracy of the information  recorded by the first analyst. We then summarized the findings about each  practice from the data collection instruments prepared for each of the six  reviews. Some practices were discussed in only one review, while others  were discussed in more than one review.
section_title: The Research Literature Shows That Some Policing Practices May be Effective in Reducing Crime
paragraphs: Our analysis of six systematic reviews of evaluations of the effectiveness  of various policing practices in preventing crime indicates that the current  evidence ranges from moderate to strong that problem-oriented policing  practices and place-oriented practices are either effective or promising as  strategies for addressing crime problems. For example, problem-oriented  approaches that focus on criminogenic substances such as guns and drugs  appear to be effective in reducing both violent and property crimes. And  hot spots approaches—place-oriented approaches that temporarily apply  police resources to discrete locations where crime is concentrated at  much higher rates than occurs jurisdictionwide—have also been found to  be effective in reducing crime. However, the magnitudes of the effects of  these interventions are difficult to estimate, especially on citywide crime  rates, as the interventions that were reviewed as effective generally were  concentrated in comparatively small places. Further, the enduring nature  of these interventions is not fully understood. It is not known, for example,  how long the effects of a problem- or place-oriented intervention persist.  In addition, some of the reviews point out that research designs  undertaken to date make it difficult to disentangle the effects of problem- oriented policing from hot spots policing. There is suggestive, but limited,  evidence that the combination of these practices may be more effective in  preventing or reducing crime than any one strategy alone.
In contrast to the findings on problem-oriented and place-oriented policing  practices, there is little evidence in the literature for the effectiveness of  community collaboration practices—such as increasing foot patrol,  establishing community partnerships, and encouraging citizen  involvement—in reducing or preventing crime.
section_title: Appendix VIII: Comments from the Department of Justice
section_title: Appendix IX: GAO Contacts and Staff Acknowledgments
subsections: section_title: GAO Contacts
section_title: Acknowledgments
paragraphs: In addition to those named above the following individuals made key  contributions to this report: William J. Sabol, Tom Jessor, David R. Lilley,  Benjamin A. Bolitzer, George H. Quinn, Jr., and Grant M. Mallie. Others  contributing included David P. Alexander, Harold J. Brumm Jr., Scott  Farrow, Kathryn E. Godfrey, Adam T. Hatton, Ronald La Due Lake,  Terence C. Lam, and Robert Parker.
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