Selected Characteristics of Private and Public Sector Workers
Released: 2014-03-21T00:00:00

An issue for Congress and state and local governments is whether the pay and benefits of public workers are comparable to those of workers in the private sector. The effect of the recession that officially began in December 2007 and ended in June 2009 on government budgets increased the interest of policy makers in the compensation of public sector employees. According to the Congressional Budget Office (CBO), the federal deficit has fallen since FY2009. But, CBO projects that the deficit for FY2014 will be $514 billion. Several state and local governments also face budget shortfalls. Among the ways to reduce budget deficits, policy makers are considering the pay and benefits of public sector employees.

This report begins with an analysis of the trends in employment in the private and public sectors. The public sector is separated into employees of the federal government, state governments, and local governments. Next, the report analyzes selected characteristics of private and public sector workers. These characteristics are often used in comparisons of the compensation of different workers. The report does not compare the actual pay or benefits of private and public sector workers or compare the characteristics of workers to try to explain any differences in the pay or benefits of private and public sector workers.

Trends in Private and Public Sector Employment

The first part of this report examines the trends in employment in the private and public sectors in the United States. The data are from the Current Employment Statistics (CES) survey, which is an employer survey conducted by the Bureau of Labor Statistics (BLS). Employment includes all full-time and part-time workers of any age. Data are for 1955 to 2013. The beginning year of 1955 is used because that is the first year that the CES survey provides data on the number of employees by level of government (i.e., federal, state, and local governments). In the CES, federal employment includes civilian employees only; the military is not included.

The number of people employed in both the private and public sectors has increased steadily as the U.S. economy has grown. From 1955 to 2013, employment in the private sector increased by 70.8 million jobs (from 43.7 million to 114.5 million), while employment in the public sector grew by 14.8 million jobs (from 7.0 million to 21.9 million after rounding). (See Figure 1 .)

From 2007 to 2010—during and after the 2007-2009 recession—private sector employment fell by an estimated 7.9 million jobs, while public sector employment increased by almost 272,000 jobs. Conversely, from 2010 to 2013, private sector employment grew by approximately 6.7 million jobs, while public sector employment fell by an estimated 626,000 jobs.

The period from 1955 to 2013 shows that, until 1975, public employment increased as a share of total employment, but has fallen since. In 1955, public sector employment accounted for 13.8% of total employment. This percentage increased to 19.2% in 1975, and then fell to 15.7% in 1999. From 1999 to 2010, public sector employment increased from 15.7% to 17.3% of total employment. Reflecting the effects of the 2007-2009 recession on the budgets of state and local governments, from 2010 to 2013 public sector employment fell from 17.3% to 16.0% of total employment. (See Figure 2 .)

From 1955 to 2013, the growth in public sector employment occurred mainly among local governments. At the local level, employment rose by an estimated 10.5 million jobs (from 3.6 million to 14.1 million). Employment at the state level rose by about 3.9 million jobs (from 1.2 million to 5.0 million after rounding). Employment in the federal government (including the Postal Service) grew by approximately 471,000 jobs (from 2.3 million to 2.8 million). (See Figure 3 .)

Since the end of the 2007-2009 recession, public sector employment has fallen. In 2013, local governments had 521,000 fewer jobs than in 2008. State governments had 129,000 fewer jobs than in 2008. In 2013, there were approximately 211,000 fewer federal jobs than in 2010.

The share of total employment accounted for by local governments peaked at 11.4% in 1975. This percentage fell through the late 1980s and then rose to 11.1% in 2009. From 2009 to 2013, the share of total employment at the local level fell from 11.1% to 10.3%. (See Figure 3 .)

The share of total employment accounted for by state governments also peaked in 1975, at 4.1%. By 2013, this percentage had fallen to 3.7%.

Including the Postal Service, in 2013 the federal government employed an estimated 471,000 more workers than in 1955 (an increase from 2.3 million to 2.8 million). (See Figure 3 .) Nevertheless, from 1955 to 2013, federal employment as a share of total employment fell from 4.5% to 2.0% (a decline of 2.5 percentage points). (See Figure 4 .)

The Number and Percent of Workers Covered by a Collective Bargaining Agreement

Some workers who are represented by a union are dues-paying members of the union. Other workers may be represented by a union but pay reduced, or no, dues. A worker who is covered by a union contract but does not pay dues may work in a right-to-work state, where workers are not required to provide financial support to a union. Federal workers who are covered by a union contract are not required to pay dues. Some state and local government employees who are covered by a collective bargaining agreement are not required to pay dues.

The data in this section are for workers who are represented by a union (i.e., whether or not they pay dues). The data include all full-time and part-time wage and salary workers ages 16 and over. (The data on union coverage in the section titled "Occupation" later in this report are for wage and salary workers ages 18 to 64 who work full-time.)

The number of American workers covered by a collective bargaining agreement has declined since 1979. In 1979, an estimated 23.5 million workers were covered by a union contract. By 2013, this number had fallen to 16.0 million. In 2009, for the first time, a majority of workers covered by a collective bargaining agreement were employed in the public sector (8.7 million workers in the public sector, compared to 8.2 million private sector workers). By 2013, the situation had reversed; a slight majority of workers covered by a collective bargaining agreement were employed in the private sector (8.1 million private sector workers, compared to 7.9 million public sector workers).

In the public sector, most workers who are covered by a collective bargaining agreement are employed by local governments (59.0% in 2013). Another 27.2% of covered public sector workers are employed by state governments, 8.0% are employed by the federal government, and 5.8% are employed by the Postal Service.

Figure 5 shows the percentage of private and public sector workers who are covered by a collective bargaining agreement. Because union coverage is higher in the Postal Service than in the rest of the federal government, data for the Postal Service and the rest of the federal government are shown separately. The data are for 1983 through 2013. The beginning year of 1983 is used because that is the year when the CPS began to collect monthly data on union coverage.

The number of workers covered by a collective bargaining agreement is greater in the private sector than in the public sector. However, the percentage of workers covered by a union contract is greater in the public sector. In 2013, 38.7% of all public wage and salary workers were covered by a collective bargaining agreement, compared to 7.5% of private sector wage and salary workers. Nevertheless, since 1983, the percentage of workers represented by a union has fallen in both the private and public sectors. In the private sector, union coverage fell from 18.5% to 7.5% of all wage and salary workers (a decline of 11.0 percentage points). In the public sector, union coverage fell from 45.5% to 38.7% of workers (a decline of 6.8 percentage points).

In the public sector, the largest decrease in union coverage has been in the Postal Service, where coverage fell from 83.5% of workers in 1983 to 67.2% of workers in 2013 (a decline of 16.3 percentage points). In the rest of the federal government, coverage fell from 29.4% to 22.4% (a decline of 7.0 percentage points). Coverage fell from 51.0% to 44.1% among employees of local governments (a decline of 6.9 percentage points after rounding) and from 35.9% to 33.8% among state government workers (a decline of 2.1 percentage points).

Union coverage can affect the relative pay of union and nonunion workers. Workers who are represented by a union generally receive higher wages and more or better benefits than workers who are not represented by a union. The percent of workers covered by a collective bargaining agreement is higher in the public sector than in the private sector. To the extent that public sector workers can bargain over pay and benefits, greater unionization in the public sector could raise the pay of public sector workers, compared to the pay of private sector workers.

In the federal government, most employees do not bargain over wages. Salaried employees generally receive an annual pay adjustment and a locality pay adjustment, effective each January. Federal employees who are paid by the hour usually receive pay adjustments equal to those received by salaried workers in the same locality.

Some federal workers can bargain over wages. The Postal Reorganization Act of 1970 (P.L. 91-375) gave postal workers the right to bargain over wages and benefits (excluding retirement benefits). Air traffic controllers can bargain over wages because the Federal Aviation Administration (FAA) is required to recognize a union chosen by a majority of employees, but is allowed to develop its own pay system. The Tennessee Valley Authority (TVA) has a long-standing policy that allows employees to bargain over wages.

Individual, Occupational, and Employer Characteristics of Private and Public Sector Workers

The second part of this report examines selected characteristics that may affect the relative pay of private and public sector workers. These characteristics include age, gender, educational attainment, and the distribution of employees by occupation. The data are from the monthly Current Population Survey (CPS) and the Annual Social and Economic (ASEC) supplement to the CPS. The CPS is a household survey conducted by the U.S. Census Bureau for BLS. The monthly CPS does not include persons on active duty in the military. The ASEC supplement includes military personnel living in civilian households.

The analysis in this section covers the period from 1976 to 2013. The national unemployment rates in 1976 and 2013 were roughly comparable (7.7% and 7.4%, respectively). Unlike the analysis of union coverage in the first part of this report, which included all full-time and part-time workers ages 16 and over, the analysis in this section is of working-age adults only. These are workers between the ages of 18 and 64. Because a larger share of workers in the public sector than in the private sector work full-time (87.2% and 80.6%, respectively, in 2013), the analysis in this section is of full-time workers only. Full-time workers are persons who usually work 35 hours or more a week. In 2013, 81.6% of workers ages 18 to 64 were employed full-time.

Age

Reflecting the aging of the U.S. labor force, workers in both the private and public sectors have become older. Nevertheless, employees in the public sector are older than private sector workers. In 2013, 51.7% of full-time public sector workers were between the ages of 45 and 64, compared to 42.4% of full-time private sector workers. (See Figure 6 .)

Federal workers are older than employees of state and local governments. In 2013, 56.7% of federal workers were between the ages of 45 and 64, compared to 49.7% of state employees and 52.1% of employees of local governments.

The age gap between private and public sector workers increased from 1976 to 2001, but has fallen since. In 1976, 35.5% of public sector workers were between the ages of 45 and 64, compared to 33.8% of private sector workers (a gap of 1.6 percentage points after rounding). By 2001, the gap had increased to 14.3 points. In 2013, the gap had fallen to 9.3 points.

Older workers typically have more years of work experience than younger workers. Employees with more work experience generally earn more than workers with less experience. Thus, the age difference between private and public sector workers may indicate that public sector workers have more years of experience than private sector workers. In turn, a difference in work experience may be reflected in differences in earnings between private and public sector workers.

Gender

Reflecting the increased participation of women in the labor force, the share of jobs held by women has increased in both the private and public sectors. However, women hold a higher share of jobs in the public sector than in the private sector, and this difference has increased over time. (See Figure 7 . ) The higher share of jobs held by women in the public sector is due mainly to the higher share of jobs held by women in state and local governments.

In 2013, women held almost three-fifths of full-time jobs in state and local governments (57.7% for both state and local governments). By contrast, women held approximately two-fifths of full-time jobs in the federal government and in the private sector (42.2% and 41.7%, respectively).

The largest increase in the share of jobs held by women has been in state governments. From 1976 to 2013, the share of state jobs held by women increased by 13.7 percentage points (from 44.0% to 57.7%). By contrast, over the same period, the share of jobs held by women in local governments increased by 8.8 points (from 48.9% to 57.7%), in the federal government by 10.7 points (from 31.5% to 42.2%), and in the private sector by 9.2 points (from 32.5% to 41.6% after rounding).

The effect of the increased employment of women on the difference in pay between private and public sector workers may be an empirical question. The share of jobs held by women in the public sector has increased more than the share of jobs held by women in the private sector. Although women, on average, earn less than men, the gap has narrowed. Evidence indicates that the pay gap between men and women is narrower in the public sector than in the private sector.

Education

On average, public sector employees have more years of education than private sector workers. In 2013, 53.6% of workers in the public sector had a bachelor's, advanced, or professional degree, compared to 34.9% of private sector workers.

Among public sector workers, state and local government employees are more likely than federal workers to have a bachelor's, advanced, or professional degree. In 2013, 57.9% of state workers and 53.5% of local government workers had at least a bachelor's degree, compared to 46.9% of federal workers.

Beginning in 1992, the CPS changed the way educational attainment is coded. For years before 1992, the CPS reported the number of years of education that a person completed, whether or not they received a degree. In 1992, the CPS began to report whether a person received a degree. Therefore, data for the years 1992 and later are not completely comparable to earlier years. (See the discussion of "CPS Values for Educational Attainment" in the Appendix .) For private and public sector workers, the percentage point changes in educational attainment discussed in this section are the sum of the percentage point changes over two periods: 1976 to 1991, and 1992 to 2013.

For public sector workers, the CPS began to collect information on employment by level of government (i.e., federal, state, or local) in 1988. Accordingly, for federal, state, and local workers, the percentage point changes in educational attainment discussed in this section are the sum of the percentage point changes from 1988 to 1991 and 1992 to 2013.

Reflecting the general rise in years of education, educational attainment has improved among both private and public sector workers. Educational attainment has improved more in the private sector than in the public sector, however. From 1976 to 2013, the percentage of private sector workers with a bachelor's degree or better increased by 19.9 percentage points, compared to a 15.2-point increase for public workers. Among private sector workers, the largest gain was in the percentage of workers with a bachelor's degree (a gain of 13.2 percentage points for private sector workers, compared to a gain of 3.8 percentage points for public sector workers). (See Figure 10 .) By contrast, the largest gain among public sector workers was among workers with an advanced or professional degree (a gain of 11.4 percentage points for public sector workers, compared to a gain of 6.6 percentage points for private sector workers). (See Figure 10 .)

Figure 10 shows changes in the level of educational attainment, from 1988 to 2013, for federal, state, and local government employees. The largest gains in educational attainment were among federal workers. The percentage of federal employees with a bachelor's, advanced, or professional degree increased by 17.0 percentage points, compared to a 13.7 point increase for employees of state governments and a 5.3 point increase for employees of local governments. The percentage of federal employees with a bachelor's degree increased by 6.4 percentage points, while the percentage with an advanced or professional degree increased by 10.6 points.

Workers with more education generally earn more than workers with less education. Other things being equal, the higher educational attainment of public sector workers, especially workers with an advanced or professional degree, likely affects the relative pay of private and public sector workers.

Occupation

The CPS provides occupational data for both major and detailed occupations. A comparison of private and public sector employment using major occupational categories shows that there are private and public workers in all major occupations. An analysis of detailed occupations, however, shows that many occupations are concentrated in either the private or public sectors.

Continuing with the methodology used in the second part of this report, the analysis in this section is of full-time workers who are between the ages of 18 and 64. Because self-employed workers are not covered by federal labor relations statutes, the analysis is of wage and salary workers only. (The analysis in the first part of this report of the number of workers covered by a collective bargaining agreement was for all full-time and part-time wage and salary workers ages 16 and over.)

Major Occupations

Table 1 shows the distribution of employment in the private and public sectors by five broad occupational categories. These five categories are subdivided into 22 major occupations. The estimates are monthly averages for calendar year 2013.

All of the occupations in Table 1 are common to both the private and public sectors. However, in 2013, a larger share of public sector than private sector workers were employed in "management, professional, and related occupations" (56.2% of public sector workers, compared to 37.8% of private sector workers). In part, more public sector workers were employed in these occupations because 25.7% of all public sector workers were employed in "education, training, and library" occupations, compared to 2.3% of all private sector workers. Public sector employees in these occupations work mainly for state and local governments (25.5% of employees in state governments and 34.4% of employees in local governments). In general, the median weekly earnings of full-time workers employed in management, professional, and related occupations are higher than the earnings of workers in other occupations.

A larger percentage of public sector than the private sector workers were employed in "protective service" occupations (11.8% and 0.7%, respectively). On the other hand, more workers in the private sector were employed in "sales and related" occupations (10.9% in the private sector and 0.8% in the public sector). Similarly, more workers in the private sector were employed in "production" occupations (7.9% in the private sector and 1.2% in the public sector).

Union Coverage by Major Occupation

Table 1 also shows the percentage of private and public sector workers in each of 5 sectors and 22 major occupations who were covered by a collective bargaining agreement in 2013. In all major occupations for which data are available (21 of 22 occupations), union coverage was higher in the public sector than in the private sector.

In the private sector, 7.9% of all full-time employees were covered by a collective bargaining agreement. But, only 2.0% of employees in legal occupations and 2.4% of employees in management occupations were represented by a union. By contrast, 18.9% of workers in education, training, and library occupations; 18.6% of workers in construction and extraction occupations; 16.1% of workers in transportation and material moving occupations; 15.9% of workers in installation, maintenance, and repair occupations; and 14.5% of production workers were represented by a union.

In the public sector, 41.3% of full-time employees were covered by a collective bargaining agreement in 2013. Among employees in education, training, and library occupations, 56.5% were represented by a union, as were 52.6% of employees in protective service occupations. A majority of employees in the latter two occupations are employed by local governments. By contrast, 18.8% of public employees employed in legal occupations and 21.6% of employees in management occupations were represented by a union. (See Table A-1 .)

Detailed Occupations

Broad occupational categories may not fully distinguish between detailed occupations that are concentrated in either the private or public sectors. Many detailed occupations may require similar skills, however. The Appendix shows the top 100 occupations, by the number of persons employed full-time in the private sector and the top 100 occupations by the number of persons employed full-time in the public sector. In 2013, the top 100 occupations in the private sector accounted for 74.0% of total full-time employment in the sector. The top 100 occupations in the public sector accounted for 83.9% of full-time employment in the sector.

Pay comparisons between the private and public sectors that rely on broad occupational categories may not capture differences in detailed occupations. On the other hand, pay comparisons that use detailed occupations may be difficult if employment in the occupation is concentrated in either the private or public sectors. For example, in 2013, 12.7% of full-time jobs in the private sector and 8.1% of full-time jobs in the public sector were in management. (See Table 1 .) But, 94.8% of chief executives worked in the private sector. (See line 12 of Table A-2 .) Similarly, 99.1% of first-line supervisors of retail sales workers and 97.7% of first-line supervisors of nonretail sales workers were employed in the private sector. (See lines 1 and 5 of Table A-3 .) On the other hand, virtually all (100.0%) first-line supervisors of police officers and detectives were employed in the public sector. (See line 10 of Table A-4 .)

On average, chief executives likely earn more, and first-line supervisors probably earn less, than mid-level managers. Whether employed in the private or public sectors, management occupations may require similar skills.

Data by detailed occupation also show that union coverage is higher in the public sector than in the private sector. (For example, see Table A-2 and Table A-4 .)

Metropolitan Area

Figure 11 shows the percentage of private and public sector workers who live in metropolitan areas with populations of 1 million or more or with populations of 5 million or more. Persons who live in areas with populations of 5 million or more are included with persons who live in areas with populations of 1 million or more. The estimates are for a worker's place of residence at the time of the 2013 ASEC supplement survey.

The cost of living is generally higher in metropolitan than nonmetropolitan areas. Thus, earnings across areas may vary because of differences in the cost of living. In 2013, private and federal employees were as likely to live in metropolitan areas of 1 million or more (57.8% for private sector workers and 58.8% for federal workers). By contrast, state employees were less likely (39.3%) than private or federal workers to live in areas with 1 million people or more.

However, private sector workers were more likely than federal workers to live in areas with 5 million or more people. In 2013, 20.5% of private sector workers lived in the largest metropolitan areas, compared to 12.9% of federal workers. On the other hand, employees of local governments were as likely (21.0%) as private sector workers to live in metropolitan areas of 5 million or more people.

Appendix. Detailed Data and Description of Data Source and Methodology

This appendix provides detailed information on employment and union coverage by occupation in the private and public sectors. It also describes the survey data and methodology used in the report.

Table A-1 shows the data used to calculate the percentages shown in Table 1 .

Table A-2 , Table A-3 , and Table A-4 show the largest 100 occupations in 2013 in the private sector and the largest 100 occupations in the public sectors. The tables show the total number of persons employed, the number of workers employed in the private and public sectors, the percentage of total employment that was in the private sector, and the percentage of workers in the private and public sectors who were covered by a collective bargaining agreement.

In 2013, among the top 100 occupations in the private sector and the top 100 occupations in the public sector, 56 occupations were common to both sectors. These 56 occupations are shown in Table A-2 . The occupations are listed in descending order of the total number of workers employed. To illustrate, of the 2,941,000 workers employed as "managers, all other," 2,503,000 were employed in the private sector and 438,000 were employed in the public sector. Of the total number of workers employed as "managers, all other," 85.1% worked in the private sector. Of the 2,941,000 "managers, all other" employed in the private sector, 1.8% were covered by a collective bargaining agreement, while 19.1% of public sector workers in this occupation were represented by a union.

Considering those occupations where less than 90% were employed in either the private or public sectors, occupations that were common to both the private and public sectors include managers; elementary and middle school teachers; registered nurses; secretaries and administrative assistants; accountants and auditors; janitors and building cleaners; managers of office and administrative support workers; and general and operations managers.

A disproportionate share of workers in some occupations common to both the private and public sectors were employed in only one sector. For example, for 21 of the 56 occupations in Table A-2 , at least 90.0% of workers were employed in the private sector. These occupations include cashiers; laborers and material movers; stock clerks and order fillers; drivers; customer service representatives; chief executives; maids and housekeeping cleaners; financial managers; automotive service technicians and mechanics; software developers; management analysts; cooks; receptionists and information clerks; electricians; and pipelayers, plumbers, pipefitters, and steamfitters.

On the other hand, large shares of workers employed in occupations common to both the private and public sector were employed in the public sector. These occupations include elementary and middle school teachers; postsecondary teachers; education administrators; social workers; counselors; and preschool and kindergarten teachers.

Table A-3 shows the 44 occupations, among the top 100 occupations in the private sector, that were not present among the top 100 occupations in the public sector. These occupations are listed in descending order by the number of workers employed in the private sector. Of the workers employed in these 44 occupations, 97.6% worked in the private sector. These occupations were mainly in sales, food preparation and serving, construction, production, automotive service, real estate, farming, and the clergy.

Table A-4 shows the 44 occupations, among the top 100 occupations in the public sector, that were not present among the top 100 private sector occupations. The occupations are listed in descending order by the number employed in the public sector. Of the workers employed in these 44 occupations, 62.2% worked in the public sector. These occupations were mainly in public safety (e.g., bailiffs, correctional officers, and jailers; police officers; fire fighters; probation officers and correctional treatment specialists; and detectives and criminal investigators); the Postal Service; education (e.g., special education, secondary school teachers, librarians, and teaching assistants) highway maintenance; eligibility interviewers for government programs; and legal occupations (e.g., court, municipal, and license clerks and legal support occupations).

Data and Methodology

This report analyzes data from the Current Employment Statistics (CES) survey and the Current Population Survey (CPS).

The CES is an employer survey conducted by the Bureau of Labor Statistics (BLS). The CES survey counts the number of persons on employer payrolls for any part of the pay period that includes the 12 th day of the month. Persons who are on the payroll of more than one establishment are counted in each establishment. Government employment includes civilian employees only; persons in the military are not included. Also excluded are employees of the Central Intelligence Agency, the National Security Agency, the National Imagery and Mapping Agency, and the Defense Intelligence Agency.

The CPS is a household survey conducted by the U.S. Census Bureau for BLS. The monthly CPS is the source of the national unemployment rate and other labor market information. The survey is representative of the civilian noninstitutional population. The sample does not include persons living in institutions (such as psychiatric hospitals, nursing homes, or correctional facilities). The monthly survey does not include individuals who are on active duty in the military. Approximately 55,500 households are interviewed each month. The data for occupations and union coverage ( Table 1 in the text and the tables in the Appendix ) are from the monthly CPS. Union coverage is for a worker's occupation at the time of the monthly CPS.

Each year, the CPS conducts the Annual Social and Economic (ASEC) supplement to the monthly CPS. The sample for the ASEC supplement is representative of the civilian noninstitutional population of the United States. The sample for the supplement includes members of the Armed Forces living in civilian housing units on a military base or in a household not on a military base, provided that at least one civilian adult lives in the same household. The supplement does not ask active members of the Armed Forces the monthly CPS labor force questions. The supplement does not include persons living in military barracks. For the 2013 supplement, 75,500 households were interviewed.

In this report, data on the characteristics of private and public sector workers are from the ASEC supplement. Data for employment by level of government are for are a person's current job.

The data that are available to public users of the CPS may not be the same as the data available to BLS. In order to protect the confidentiality of persons in the survey, the Census Bureau modifies (or "masks") the age variable in the data available to public users. As a result, some estimates produced by public users of the CPS may not match estimates published by BLS.

Changes in the Reporting of Educational Attainment in the Current Population Survey (CPS)

In 1992, the CPS changed the way educational attainment is recorded. Table A-5 shows the values for educational attainment for the years 1975 to 1991 and the values for 1992 to 2013. For 1976 to 1991, the CPS recorded the number of years of school that a person attended. Another variable recorded whether the person finished that year of school. Since 1992, the CPS has reported whether a person graduated from high school or college.

Because of the change in the way the CPS records educational attainment, estimates of the number of high school and college graduates for the years 1992 to 2013 are not comparable to estimates for earlier years. For the earlier period, persons who completed 12 years of high school may or may not have graduated from high school. Similarly, persons who finished 16 or more years of education may or may not have received a bachelor's, advanced, or professional degree. Because of the change in coding for educational attainment, changes in educational attainment discussed in this report are the sum of changes over two periods: the period to 1991 and the period since 1992.