optimal inflation tax under precommitment theory and evidence the authors develop and test the orthogonality conditions implied by a dynamic model of the inflation tax a distinguishing feature of the analysis is that the welfare loss from inflation the money demand function and the time path of inflation are jointly derived from first principles of government and private sector intertemporal optimization quarterly data for argentina brazil and israel are used in implementing the model although the overidentifying restrictions of the model are not rejected in most cases there are several data points characterized by higher rates of inflation than the optimal rates under precommitment copyright 1992 by american economic association

money demand and seigniorage maximizing inflation conventional estimates of the seigniorage maximizing inflation rate often make use of the cagan form which implies a constant semielasticity of money demand with respect to inflation this paper shows that the elasticity of substitution in transactions between money and bonds determines how the inflation semielasticity of money demand changes as inflation rises allowing for a variable semielasticity estimates of seigniorage maximizing inflation for a panel of eleven high inflation countries are lower than those obtained by using the cagan form estimates based on the correct measure of the opportunity cost of money also differ sharply from those obtained when using conventional inflation measures copyright 1995 by ohio state university press

budget deficits stability and the monetary dynamics of hyperinflation hyperinflationary processes usually occur in countries with extremely large budget deficits in models of inflationary finance with rational expectations e g buiter 1987 large budget deficits cannot lead to hyperinflation the purpose of this paper is to reconcile the standard theoretical model with the stylized facts it shows that by introducing a lag in the adjustment of the money market into the standard inflationary finance model large budget deficits are indeed the main reason for hyperinflation the paper also provides an explanation for the ineffectiveness of moderate reductions in the deficit in reducing inflation and argues that fiscal lags can be destabilizing copyright 1989 by ohio state university press

prices policing and policy the dynamics of crime booms and busts in many historical episodes criminal activity displays booms and busts one clear example is the case of metal crime in the uk and elsewhere where in the face of big increases in value driven by world commodity prices thefts rose very sharply in the 2000s after which they fell this paper studies the respective roles of prices policing and policy in shaping this crime boom and bust separate study of each reveals metal crime being driven up via sizeable and significant metal crime price elasticities and driven down by changes in policing and policy a regression based decomposition analysis confirms that all three of the hypothesised factors considered in the paper prices policing and policy were empirically important in the different stages of metal theft s boom and bust

the demand for money in developing countries assessing the role of financial innovation traditional specifications of money demand have commonly been plagued by persistent overprediction implausible parameter estimates and highly autocorrelated errors the authors argue that some of these problems stem from the failure to account for the impact of financial innovation they estimate money demand for ten developing countries using various proxies for financial innovations they also assess the relative importance of this variable finding financial innovation can be better modeled as a stochastic random walk trend rather than a deterministic time trend financial innovation plays an important role in determining fluctuations of the demand for money the importance of this role increases with the rate of inflation

measuring positive externalities from unobservable victim precaution an empirical analysis of lojack lojack is a hidden radio transmitter device used for retrieving stolen vehicles because there is no external indication that lojack has been installed it does not directly affect the likelihood that a protected car will be stolen there may however be positive externalities due to general deterrence we find that the availability of lojack is associated with a sharp fall in auto theft rates of other crime do not change appreciably at least historically the marginal social benefit of an additional unit of lojack has been fifteen times greater than the marginal social cost in high crime areas those who install lojack however obtain less than 10 percent of the total social benefits leading to underprovision by the market

squealer dealers the market for information in federal drug trafficking prosecutions never rat on your friends and always keep your mouth shut jimmy conway goodfellas citing his invaluable aid in the war against the mafia a federal judge yesterday rewarded a once powerful mob figure who became a major government informer by sentencing him to just five years in prison despite his admitted involvement in 19 murders the new york times september 27 19941 i introduction since the seminal theoretical work of becker 1968 the economics of crime has developed an extensive empirical literature 2 this article adds to that literature by studying markets for information in federal prosecutions of drug trafficking conspiracies in these markets law enforcement demands information that can help prosecute and imprison suspected drug traffickers while other drug traffickers supply the information 3 the price over which demanders and suppliers higgle is the size of an informer s sentence reduction 4 mustard 2001 using federal sentencing data found that different demographic groups have different rates relative quantities of providing substantial assistance the federal legal term meaning information against other defendants 5 this article adds to mustard 2001 by using federal sentencing of convicted drug traffickers to uncover whether different demographic groups have different relative prices for their information i e whether different groups receive larger sentence reductions higher prices or smaller sentence reductions lower prices when providing substantial assistance then in a simple manner similar to well known examinations of the returns to education in the 1970s and 1980s levy and mumane 1992 murphy and welch 1989 price and quantity determine whether certain groups experience different relative demand or relative supply for their testimony groups experiencing high relative demand have their information highly sought by law enforcement and therefore have high rates quantities of providing substantial assistance and large sentence reductions prices when doing so those with low relative demand have low quantities and low prices groups with high relative supply of substantial assistance have high quantities but low prices while those with low relative supply have low quantities and high prices this article further adds to the literature by going beyond demographic factors and examining what criminality related factors e g criminal history role in a criminal conspiracy and type of drug dealt affect supply and demand for information and by examining supply and demand conditional on expected prison sentence results show that women and better educated defendants experience high relative demand for information while blacks hispanics and non u s citizens experience low relative demand groups facing long prison sentences dealers of harder drugs those with long criminal histories and high level dealers have high relative supply while those facing short sentences primarily low level dealers have low relative supply when controlling for expected sentence crack dealers high level dealers and dealers with long criminal histories experience low demand race specific estimations show that women of all races experience high relative demand for information the rest of this article is organized as follows section ii discusses the federal criminal justice system emphasizing reforms established by the sentencing reform act of 1984 and the anti drug abuse act of 1986 section iii discusses the data and provides summary statistics section iv discusses my empirical methodology section v shows results and section vi attempts to explain them section vii discusses results from race specific estimations and section viii concludes ii federal criminal sentencing through most of the 1980s and before federal judges possessed near total discretion in determining sentences for criminals convicted of violating federal statutes e

evolution in games with randomly disturbed payoffs we consider a simple model of stochastic evolution in population games in our model each agent occasionally receives opportunities to update his choice of strategy when such an opportunity arises the agent selects a strategy that is currently optimal but only after his payoffs have been randomly perturbed we prove that the resulting evolutionary process converges to approximate nash equilibrium in both the medium run and the long run in three general classes of population games stable games potential games and supermodular games we conclude by contrasting the evolutionary process studied here with stochastic fictitious play

crime rates and local labor market opportunities in the united states 1979 1997 the labor market prospects of young unskilled men fell dramatically in the 1980s and improved in the 1990s crime rates show a reverse pattern increasing during the 1980s and falling in the 1990s because young unskilled men commit most crime this paper seeks to establish a causal relationship between the two trends previous work on the relationship between labor markets and crime focused mainly on the relationship between the unemployment rate and crime and found inconclusive results in contrast this paper examines the impact of both wages and unemployment on crime and uses instrumental variables to establish causality we conclude that both wages and unemployment are significantly related to crime but that wages played a larger role in the crime trends over the last few decades these results are robust to the inclusion of deterrence variables controls for simultaneity and controlling for individual and family characteristics

building criminal capital behind bars peer effects in juvenile corrections this paper analyzes the influence that juvenile offenders serving time in the same correctional facility have on each other s subsequent criminal behavior the analysis is based on data on over 8 000 individuals serving time in 169 juvenile correctional facilities during a two year period in florida these data provide a complete record of past crimes facility assignments and arrests and adjudications in the year following release for each individual to control for the non random assignment to facilities we include facility fixed effects thereby estimating peer effects using only within facility variation over time we find strong evidence of peer effects for various categories of theft burglary and felony drug and weapon crimes the influence of peers primarily affects individuals who already have some experience in a particular crime category we also find evidence that peer effects are stronger in smaller facilities and that the predominant types of peer effects differ in residential versus non residential facilities effects in the latter are consistent with network formation among youth serving time close to home

interest rates and the exchange rate a non monotonic tale abstract for over 30 years the empirical international finance literature has been unable to detect a clear systematic relationship between interest rates and the nominal exchange rate we take a fresh look at the data and uncover a new stylized fact for a cross section of countries the relationship between the exchange rate and short term interest rates is non monotonic small increases in the nominal interest rate appreciate the currency whereas larger increases depreciate the currency we develop a model that explains this stylized fact based on the interaction of three effects higher interest rates increase money demand and hence appreciate the currency but also raise the fiscal deficit and depress output both of which tend to depreciate the currency we provide cross country evidence for the presence of these effects in the data

changing the price of marriage evidence from blood test requirements abstract we use state repeals of blood test requirements btrs for a marriage license that occurred between 1980 and 2008 to examine the impact of changes in the price of marriage on the marriage decision using a within group estimator that holds constant state and year effects and exploits variation in the repeal dates of btrs across states we find that btrs are associated with a 6 1 percent decrease in marriage licenses issued by a state this main finding is supported with results from individual level marriage license and current population survey data the largest effects are found for lower socioeconomic groups

the stability of price dispersion under seller and consumer learning in many markets it is possible to find rival sellers charging different prices for the same good earlier research has attempted to explain this phenomenon by demonstrating the existence of dispersed price equilibria when consumers must make use of costly search to discover prices we ask whether such equilibria can be learned when sellers adjust prices adaptively in response to current market conditions with consumer behavior fixed convergence to a dispersed price equilibrium is possible in some cases however once consumer learning is introduced the monopoly outcome first found by diamond journal of economic theory3 1971 156 68 is the only stable equilibrium

seigniorage operating rules and the high inflation trap there may be both a high and a low inflation equilibrium when the government finances the deficit through seigniorage under rational expectations the high inflation equilibrium is stable and the low inflation equilibrium unstable under adaptive expectations or lagged adjustment of money balances with rational expectations the low inflation equilibrium may be stable adding bond financing dual equilibria remain if the government fixes the real interest rate but a unique equilibrium is attained when the government sets a nominal anchor for the economy the existence of dual equilibria is thus a result of the government s operating rules

empirical estimates of inflation tax laffer surfaces a 30 country study abstract long run or steady state inflation tax laffer surfaces are estimated with annual data over the 1960s through early 1990s for a varied group of 30 countries using the cagan semi elastic demand for currency and for deposits the model includes an explicit role for the reserve ratio variations in which are shown to be important in explaining inflation tax revenue statistically countries inflation and reserve ratio management are examined in terms of where they operated with respect to steady state laffer boundaries defined as the locus of instruments inflation and reserve ratio that maximize the inflation tax analysis is performed both in terms of sample means of the instruments and their annual values each approach requiring a different conceptual framework few countries operated frequently on the wrong side of the laffer surface

corruption trade costs and gains from tariff liberalization evidence from southern africa this paper exploits quasi experimental variation in tariffs in southern africa to estimate trade elasticities traded quantities respond only weakly to a 30 percent reduction in the average nominal tariff rate trade flow data combined with primary data on firm behavior and bribe payments suggest that corruption is a potential explanation for the observed low elasticities in contexts of pervasive corruption even small bribes can significantly reduce tariffs making tariff liberalization schemes less likely to affect the extensive and the intensive margins of firms import behavior the tariff liberalization scheme is however still associated with improved incentives to accurately report quantities of imported goods and with a significant reduction in bribe transfers from importers to public officials

under the cover of darkness how ambient light influences criminal activity abstract we exploit daylight saving time dst as an exogenous shock to daylight using both the discontinuous nature of the policy and the 2007 extension of dst to consider the impact of light on criminal activity regression discontinuity estimates show a 7 decrease in robberies following the shift to dst as expected effects are largest during the hours directly affected by the shift in daylight we discuss our findings within the context of criminal decision making and labor supply and estimate that the 2007 dst extension resulted in 59 million in annual social cost savings from avoided robberies

testing for the effects of concealed weapons laws specification errors and robustness abstract in 1997 john lott and david mustard published an important paper in which they found that right to carry concealed weapons laws reduce violent crime although lott and mustard appear to do all possible variations of the analysis a closer reading reveals that the study might suffer from several possibly important errors i reestimate the model and check for incorrect functional form omitted variables and possible second order bias in the t ratios lott and mustard s basic conclusions are generally robust with respect to these potential econometric problems overall right to carry concealed weapons laws tend to reduce violent crime the effect on property crime is more uncertain i find evidence that these laws also reduce burglary

does the disclosure of gun ownership affect crime evidence from new york abstract while the social costs of gun violence are high opponents of gun restrictions argue that gun ownership deters crime and creates a positive externality by increasing unobserved risk to criminals this paper investigates the evidence for these two deterrence channels exploiting the sudden disclosure of all handgun permit holders names and addresses in two new york counties permit holders have more crime incidents at their homes relative to non permit holders in the baseline which is not driven by selection into neighborhoods i find little evidence in favor of direct deterrence and little evidence of peer deterrence instead i find that victimization is associated with a higher likelihood of future gun ownership

on the learning and stability of mixed strategy nash equilibria in games of strategic substitutes abstract this paper analyzes the learning and stability of mixed strategy nash equilibria in games of strategic substitutes gss complementing recent work done in the case of strategic complements gsc mixed strategies in gss are of particular interest because it is well known that such games need not exhibit pure strategy nash equilibria first we establish bounds on the strategy space which indicate where randomizing behavior may occur in equilibrium second we show that mixed strategy nash equilibria are generally unstable under a wide variety of learning rules multiple examples are given

money demand and exchange rate determination under hyperinflation conceptual issues and evidence from yugoslavia a modified monetary model of exchange rate determination is advanced and tested for the yugoslav hyperinflation of 1992 94 stating that the exchange rate is determined directly in the money market thus implying that private agents due to dollarization denominate their real money holdings in foreign currency empirical evidence supports the advanced model apart from the last seven months of the yugoslav hyperinflation the exact re present value model of the exchange rate is accepted while that of the price level is rejected for the whole period of hyperinflation the modified money demand schedule with money holdings denominated in foreign currency is nonlinear with decreasing semielasticity of money demand

more guns more crime this paper examines the relationship between gun ownership and crime previous research has suffered from a lack of reliable data on gun ownership i exploit a unique data set to reliably estimate annual rates of gun ownership at both the state and the county levels during the past two decades my findings demonstrate that changes in gun ownership are significantly positively related to changes in the homicide rate with this relationship driven almost entirely by an impact of gun ownership on murders in which a gun is used the effect of gun ownership on all other crime categories is much less marked recent reductions in the fraction of households owning a gun can explain one third of the differential decline in gun homicides relative to nongun homicides since 1993

the social costs of gun ownership abstract this paper provides new estimates of the effect of household gun prevalence on homicide rates and infers the marginal external cost of handgun ownership the estimates utilize a superior proxy for gun prevalence the percentage of suicides committed with a gun which we validate using county and state level panels for 20 years we estimate the elasticity of homicide with respect to gun prevalence as between 0 1 and 0 3 all of the effect of gun prevalence is on gun homicide rates under certain reasonable assumptions the average annual marginal social cost of household gun ownership is in the range 100 to 1800

time consistent collection of optimal seigniorage a unifying framework this paper reviews the existing literature on the time consistency problem of seigniorage collection when monetary policy is determined by optimal taxation considerations it develops a unifying accounting framework and suggests a general measure for seigniorage which encompasses the standard measures employed in the literature in addition the ex ante optimal solution to the optimal taxation problem is derived and interpreted in relation to the ramsey principle we show that the different recommendations of the public finance literature i e the friedman rule of optimal deflation moderately positive inflation and seigniorage maximizing inflation are specific solutions to the optimal taxation problem the paper continues with a formal illustration of the time consistency problem of the ex ante optimal policy and the characterization of the time consistent solution under discretion as possible solutions to the time consistency problem we consider reputational forces institutional reforms that establish central bank independence and specific ways of asset and debt management in particular it is formally shown that a modified version of the asset and debt management scheme suggested by persson persson and svensson is not only necessary but also sufficient for optimality although this did not hold in their model

seigniorage revenue deficits and self fulfilling currency crises abstract this paper examines potential resolutions to the conflict between a fixed exchange rate and seigniorage revenue requirement of a stylized developing economy that gives rise to a currency crisis the government has an informational advantage and can decide when it is optimal to invoke an escape clause i e to drop the peg and float speculators must guess when the crisis will happen based on their assessment of the probability of collapse and this makes pegged exchange rate equilibria unstable

wto accession and tariff evasion abstract this study documents some unintended consequences of the world trade organization wto membership by providing evidence on displacement of tariff evasion driven by the wto accession process the analysis focuses on the wto customs valuation agreement cva which limits the discretion of customs officials when it comes to assessing the price of imports while prior to the wto accession customs officials are free to use their own judgment or apply minimum or reference prices after their country joined the wto they are mandated to accept the invoice price issued by the exporter if customs officials enjoy discretion with respect to assessing the import price they may assist importers with tariff evasion in exchange for bribes removing such discretion limits their ability to facilitate misrepresentation of import prices using data on 15 countries which joined the wto between 1996 and 2008 we find a positive relationship between underreporting of import prices and the tariff rate which is expected as the incentive to evade increases with the tariff rate importantly this relationship disappears after a country joins the wto this result is consistent with the cva closing one channel for corrupt behavior however we also find that changes to customs valuation procedures induce importers to seek alternative ways of tariff evasion such as underreporting of quantities and product misclassification the overall level of evasion remains unchanged

cagan s paradox and money demand in hyperinflation revisited at daily frequency using daily data the cagan money demand is estimated and accepted for the most severe portion of serbia s 1992 1993 hyperinflation i e its last 6 months an implication is that the public adjusted daily throughout this extreme period moreover the obtained semi elasticity estimates are by far lower than those previously found using monthly data sets consequently the daily estimates reject the longstanding cagan s paradox based on monthly studies by showing that the economy has been on the correct increasing side of the laffer curve almost through the end of hyperinflation this strongly supports the view that hyperinflation is triggered and driven all way through its end by the government s hunt for non decreasing seigniorage daily adjustments of public in hyperinflation can account for the difference between the results obtained at daily and monthly frequencies calling into question the latter some evidence is offered that the findings of this paper may hold for other hyperinflations

the logit equilibrium a perspective on intuitive behavioural anomalies costs associated with deviations from the nash equilibrium these payoff asymmetry effects are incorporated in an approach that introduces noisy behavior via a logit probabilistic choice function in the resulting logit equilibrium behavior is characterized by a probability distribution that satisfies a rational expectations consistency condition the beliefs that determine players expected payoffs match the decision distributions that arise from applying the logit rule to those expected payoffs we prove existence of a unique symmetric logit equilibrium and derive comparative statics results the paper provides a unified perspective on many recent laboratory studies of games in which nash equilibrium predictions are inconsistent with both intuition and experimental evidence

fictitious play property for games with identical interests abstract ann person game has identical interests if it is best response equivalent in mixed strategies to a game with identical payoff functions it is proved that every such game has the fictitious play property journal of economic literatureclassification numbers c72 c73

reexamining criminal behavior the importance of omitted variable bias to what extent do changes in the expected penalty alter the willingness of individuals to engage in illegal activity becker 1968 developed a theoretical model of criminal behavior that asserted offenders respond to incentives in much the same way as those who engage in legal activities respond ehrlich 1973 pioneered empirical tests of the model and concluded that there was a strong positive correlation between income inequality and property crimes that the crime rate was positively related to relative gains and negatively related to the costs associated with criminal activity and that law enforcement activity had a deterrent effect for all crimes recently many papers have used arrest rates to mea

a note on best response dynamics we investigate the relationship between the continuous time best response dynamic its perturbed version and evolutionary dynamics in relation to mixed strategy equilibria we find that as the level of noise approaches zero the perturbed best response dynamic has the same qualitative properties as a broad class of evolutionary dynamics that is stability properties of equilibria are robust across learning dynamics of quite different origins and motivations journal of economic literature classification numbers c72 d83

crime protection investment spillovers theory and evidence from the city of buenos aires abstract this paper studies spillover effects from private crime protection technologies criminals and victims interact in a frictional market for offenses private protection diverts crime towards unprotected targets but also discourages criminal activity the relative strength of these two effects determines the sign of externalities among potential victims using originally collected data from buenos aires evidence shows that i private protection investment is spatially concentrated and ii neighbors investment in private protection has a causal positive and significant effect on own investment to achieve identification i exploit variation in the investment status of close neighbors as induced by their knowledge of crimes targeting friends relatives acquaintances or others and occurred farther away neighbors investment in alarms and cameras significantly increases a household s propensity to invest in the same technology externalities raise the scope for government intervention while geo referenced information on private protection can inform policy with regard to the spatial distribution of policing effort and public investment in security

the value of technology improvements in games with externalities a fresh look at offsetting behavior abstract we model the effect of safety technology improvements in a symmetric game in which each player s payoff depends on his own precaution and the other players average precaution we derive conditions under which an improved technology increases or decreases players equilibrium utilities for mandatory safety technologies the direction of the welfare effect depends on whether the externality between players is positive or negative and on whether the technology improvement is a complement or substitute for individual precaution for safety technologies that individuals can choose whether or not to purchase individuals expend too much on reducing the loss size but may spend either too much or too little on features that reduce an individual s loss probability

an estimate of resource expenditures on transfer activity in the united states this paper details resource expenditures on nonexchange noncharity transfer activity in the united states in 1985 expenditures designed to facilitate and inhibit nonexchange transfers executed privately or through the state are reported the numbers indicate that individuals plausibly invested nearly a trillion dollars in transfer activity that year nominal gnp in 1985 was just over 4 trillion which includes numerous transfer related resource investments that arguably should be subtracted out transfer activity thus apparently constitutes a much larger fraction of all economic activity conducted in the united states than previously recognized

is financial repression a solution to reduce fiscal vulnerability the example of france since the end of world war ii this article contributes to the recent empirical literature on financial repression and focuses on the french case since the end of world war ii we find that the fiscal adjustment needed to lower the debt ratio has been smaller during the years of financial repression in comparison with those of liberalized financial markets this was possible because the real interest rates were low we conduct a counterfactual analysis to see whether the vulnerability of public finances would have been different if since the late 1980s the governments had continued carrying out the same financial repression policies we answer affirmatively showing that the cost of debt service would have been reduced

external debt inflation and the public sector toward fiscal policy for sustainable growth which tradeoffs are involved in formulating an external debt strategy should expenditure be cut to improve the current account or will this reduce future output growth thus undermining the benefits of any debt reduction are there alternatives that allow satisfactory output growth without jeopardizing creditworthiness how can the necessary surplus of savings over investment be brought about at levels of investment high enough to sustain output growth should the government contribute to the internal adjustment by reducing its deficit macroeconomic targets for inflation and growth and creditworthiness constraints on debt issue impose restrictions on the extent to which deficits can be financed can the government cover the deficit within these targets and constraints the absence of such consistency forebodes future policy change and so undermines the credibility of the adjustment program the author uses empirical work on turkey to illustrate the interactions between fiscal deficits and the macroeconomic variables upon which fiscal consistency hinges

the occupations of regulators influence occupational regulation evidence from the us private security industry licensing requirements for us private security firms and guards differ substantially from state to state state regulatory institutions for this industry also vary considerably some states have specialized regulatory boards with industry personnel guards firm owners and or public police as board members while others rely on non specialized regulators such as departments of commerce state professional regulation or consumer affairs these cross state variations in licensing requirements and regulatory institutions provide an opportunity to explore relationships between the two private security regulation is of particular interest in this context because previous empirical research implies that allocating more resources to private security reduces crime and that relatively stringent licensing requirements limit entry thereby increasing crime a panel of 1991 2010 state data is employed to see if particular regulatory institutions are associated with particular licensing requirements empirical results suggest that requirements for entry into this market tend to be relatively strict when active private security personnel are in control of licensing and that different patterns of regulation generally apply when police or non specialized agencies control licensing therefore both public interest and private interest explanations for the observed relationships between the structure of regulatory institutions and resulting licensing requirements are discussed

individual protection against property crime decomposing the effects of protection observability we re examine the efficiency of observable and unobservable crime protection decisions with new results and insights observable protection is unambiguously associated with a negative externality at the individual level it reduces the crime effort but its unit payoff remains unchanged conversely unobservable protection reduces the unit payoff and has no effect on the crime effort exerted though it deters crime globally a decrease in the global crime payoff is detrimental to a victim if protection is observable while it is beneficial when unobservable while observable protection has a positive diversion effect it has the opposite effect when unobservable on reexamine l efficacite des decisions observables et non observables de protection par rapport au crime et on en tire de nouveaux resultats et de nouvelles perspectives la protection observable est associee a une externalite negative sans aucune ambiguite au niveau individuel elle reduit l effort de crime mais laisse les resultats financiers inchanges d autre part la protection non observable reduit les resultats financiers de l unite mais n a aucun effet sur l effort de crime dans ce cas particulier meme si cela se traduit par un effet dissuasif sur le crime globalement un declin dans le rendement global de l activite criminelle nuit a une victime si la protection est observable alors qu il est benefique quand la protection n est pas observable alors que la protection observable a un effet positif de diversion elle a l effet oppose quand elle n est pas observable

the economic epidemiology of crime economic analysis of infectious diseases emphasizes the self correcting character of epidemics as rising risk of infection causes potential victims to take self protective measures we apply the analysis to crime showing how rational potential victims of crime will take increased self protective measures in response to rising crime rates causing those rates to moderate victim responses to crime can offset public expenditures on crime control this implies that there may be a natural rate of crime that is difficult for the public sector to affect we show that victim responses to crime can impart a cyclical pattern to crime rates and discuss the implications of our analysis for gun control and present empirical evidence concerning the responsiveness of self protective measures to crime rates and the cyclical pattern of those rates

insurance self protection and the economics of terrorism abstract this paper investigates the rationale for public intervention in the terrorism insurance market it argues that government subsidies for terror insurance have the effect of discouraging self protection and limiting the negative externalities associated with self protection cautious self protective behavior by a target can hurt public goods like national prestige if it is seen as giving in to the terrorists and may increase the loss probabilities faced by others by encouraging terrorists to substitute toward more vulnerable targets we argue that these externalities in protection are essential for normative analysis of government intervention in insurance markets and may also explain why availability problems in this market have engendered much stronger government responses than similar problems in other catastrophe insurance markets

evolutionary implementation in a public goods game abstract we consider implementation of the efficient state in a large population public goods game due to positive externalities the efficient state is different from the nash equilibrium of the game we apply a transfer scheme equal to the externality in the game the externality adjusted public goods game is a potential game with a unique nash equilibrium which is the efficient state of the original game it is also a continuous strategy aggregative game we introduce the best response dynamic for such aggregative potential games to show evolutionary implementation agents converge to the efficient state under this dynamic in the externality adjusted game we extend this result to other prominent evolutionary dynamics the pure externality price scheme however causes a budget deficit a modification of this scheme solves this problem while evolutionarily implementing efficiency

serial correlation and the fixed effects model this paper generalizes the durbin watson type statistics to test the ols residuals from the fixed effects model for serial independence also generalized are the tests proposed by sargan and bhargava for the hypothesis that the residuals form a random walk a method for efficient estimation of the parameters is also developed finally an earnings function is estimated using the michigan survey of income dynamics in order to illustrate the uses of the tests and the estimation procedures developed in this paper

currency crises and contingent liabilities a contingent liability is a future spending commitment that is realized with some probability international organizations emphasize the dangers of contingent liabilities when providing advice why one answer is obvious if significant contingent liabilities are realized they commit governments to substantial fiscal costs there is a further reason by taking on a contingent liability the government can increase the probability of the underlying shock taking place this paper describes how the issuance of government guarantees and the methods by which they are financed affect the probability of crises taking place it also discusses the determinants of post crisis inflation and depreciation

the social efficiency of private decisions to enforce property rights costs must be incurred if an owner is to enforce private property rights effectively we show that in a perfectly competitive economy private decisions to enforce rights may result in either more or less enforcement than is socially efficient cases of multiple stable equilibria occur and an equilibrium may be locally but not globally efficient resources may not be employed in their socially most valuable uses and enforcement may be accompanied by inefficient investment in resource productivity

learning in games with unstable equilibria we propose a new concept for the analysis of games the tasp which gives a precise prediction about non equilibrium play in games whose nash equilibria are mixed and are unstable under fictitious play like learning we show that when players learn using weighted stochastic fictitious play and so place greater weight on recent experience the time average of play often converges in these unstable games even while mixed strategies and beliefs continue to cycle this time average the tasp is related to the cycle identified by shapley l s shapley some topics in two person games in m dresher et al eds advances in game theory princeton university press princeton 1964 the tasp can be close to or quite distinct from nash equilibrium

social stability and equilibrium in the field of noncooperative game theory nash equilibrium nash 1951 has played a central role as a solution concept in bold strokes one may discern two major interpretations of nash equilibrium in the context of rational players the first which is close to the eductive interpretation of binmore 1987 1988 and the complete information interpretation of kaneko 1987 assumes that the game is played exactly once if it is a repeated game the repetition occurs once and the players have sufficient knowledge and ability to analyze the game in a rational manner sometimes it is assumed that all players have consistent hierarchies of beliefs where the game and their priors are common knowledge bayesian interpretation such as proposed by aumann 1987 advanced this idea to the level that the players have a common prior from this point of view however nash equilibrium seems far from being satisfactory

negative externalities competition and consumer choice consumers sometimes make choices that impose greater external costs on those who do not make the same choice this paper examines how the selectivity of negative externalities in such situations affects the competitive equilibrium and the desirability of an externality reducing public policy selective negative externalities create network externalities but outcomes may differ greatly from typical network effects price effects may cause the imposing product s sales to decline with the size of the negative externality consequently a positive competitive effect may overwhelm the externality s negative direct effects on welfare such that a policy that enlarges the externality may improve welfare

is it enough evidence from a natural experiment in india s agriculture markets access to information and communication technologies icts such as mobile phone networks is widely known to improve market efficiency in this paper we examine whether access to timely and accurate information provided through ict applications has any additional impact using a detailed data set from reuters market light rml a text message service in india that provides daily price information to market participants we find that this information reduces the geographic price dispersion of crops in rural communities by an average of 12 over and above access to mobile phone technology and other means of communication to identify the effect of information on price dispersion we exploit a natural experiment where bulk text messages were banned unexpectedly across india for 12 days in 2010 we find that besides reducing geographic price dispersion rml also increases the rate at which prices converge across india over time we discuss the implications of this for development organizations and informat

money and interest in a cash in advance economy the authors analyze an aggregative general equilibrium model in which the use of money is motivated by a cash in advance constraint applied to purchases of a subset of consumption goods the system is subject to both real and monetary shocks which are economy wide and observed by all they develop methods for verifying the existence of characterizing and explicitly calculating equilibria copyright 1987 by the econometric society

output costs currency crises and interest rate defence of a peg central banks typically raise short term interest rates to defend currency pegs higher interest rates however often lead to a credit crunch and an output contraction we model this trade off in an optimising first generation model in which the crisis may be delayed but is ultimately inevitable we show that higher interest rates may delay the crisis but raising interest rates beyond a certain point may actually bring forward the crisis due to the large negative output effect the optimal interest rate defence involves setting high interest rates relative to the no defence case both before and at the moment of the crisis

crime and economic incentives we explore the role that economic incentives particularly changes in wages at the bottom end of the wage distribution play in determining crime rates we use data on the police force areas of england and wales between 1975 and 1996 and find relative falls in the wages of low wage workers lead to increases in crime we carry out a number of experiments with different wage measures including a wage measure that accounts for the effects of changes in the composition of employment these reinforce the picture of a strong association between the low wage labor market and crime the result that incentives play a central role is reinforced further by the strong impact on crime of deterrence measures and of a measure of the returns to crime

consumer privacy and marketing avoidance a static model we introduce the concept of marketing avoidance consumer efforts to conceal themselves and to deflect marketing the setting is one in which sellers market some item through solicitations to potential consumers who differ in their benefit from the item and suffer harm from receiving solicitations concealment by one consumer induces sellers to shift solicitations to other consumers whereas deflection does not solicitations cause two externalities direct harm on consumers and the indirect cost of consumer concealment and deflection we find that in markets where the marginal cost of solicitation is sufficiently low efforts by low benefit consumers to conceal themselves will increase the cost effectiveness of solicitations and lead sellers to market more however concealment by high benefit consumers leads sellers to market less furthermore concealment by low benefit consumers increases direct privacy harm and consumer welfare is higher with deflection than concealment finally it is optimal to impose a charge on solicitations

the changing returns to crime do criminals respond to prices to what extent does crime follow the pattern of potential gains to illegal activity this article presents evidence on how criminals respond to this key incentive by reporting crime price elasticities estimated from a comprehensive crime dataset containing detailed information on stolen items for london between 2002 and 2012 evidence of significant positive crime price elasticities are shown for a panel of 44 consumer goods and for commodity related goods jewellery fuel and metal crimes the reported evidence indicates that potential gains are a major empirical driver of criminal activity and a crucial part of the economic model of crime the changing structure of goods prices helps to explain over 10 15 of the observed fall in property crime across all goods categories and the majority of the sharp increases in the commodity related goods observed between 2002 and 2012

are u s cities underpoliced theory and evidence we document the extent of measurement errors in the basic data set on police used in the literature on the effect of police on crime analyzing medium to large u s cities over 1960 to 2010 we obt

the dynamics of price dispersion or edgeworth variations abstract hypotheses on the dynamics of dispersed prices are extracted from computer simulations and theory and are tested using laboratory data as predicted in some variations of the edgeworth hypothesis the data exhibit a significant cycle relative to the unique stationary distribution the empirical distribution of posted prices has excess mass in an interval that declines until it approaches the lower boundary of the stationary distribution then jumps upward and the downward cycle resumes the amplitude of the cycle seems fairly constant over the longer experimental sessions a hybrid of gradient dynamics and logit dynamics seems to best reproduce the observed dynamics

an experimental study of price dispersion abstract we report an experiment examining a simple clearinghouse model that generates price dispersion according to this model price dispersion arises because of consumer heterogeneity some consumers are informed and simply buy from the firm offering the lowest price while the remaining consumers are captive and shop based on considerations other than price in our experiment we observe substantial and persistent price dispersion we find that as predicted an increase in the fraction of informed consumers leads to more competitive pricing for all consumers we also find as predicted that when more firms enter the market prices to informed consumers become more competitive while prices to captive customers become less competitive thus our experiment provides strong support for the model s comparative static predictions about how changes in market structure affect pricing

does private security affect crime a test using state regulations as instruments private security is employed to deter criminals from attacking specific targets presumably not to produce general deterrence indeed private security generates negative spillovers as criminals su

seigniorage maximizing inflation under sticky prices what is the seigniorage maximizing level of inflation three models formulae for the seigniorage maximizing inflation rate smir are compared a sticky price model prescribes a somewhat lower smir to cagan s formula and a variant of a flex price model due to kimbrough 2006 the models differ markedly in how inflation distorts the labor market the sticky price calvo model implies that inflation and output are negatively related and that output is falling in price stickiness interestingly if our version of the calvo model is to be believed the level of inflation experienced recently in advanced economies such as the united states and the united kingdom may be quite close to the smir

buyer search and price dispersion a laboratory study we study markets with costly buyer search in which sellers simultaneously post prices buyers costlessly observe one or with probability 1 q two of the posted prices and can accept one or pay to search again the experiment varies q the search cost and the number of buyers equilibrium theory predicts a unified very low high price for q 0 q 1 and predicts specific distributions of dispersed prices for q 1 3 and 2 3 actual prices conform closely to the predictions in some treatments buyers reservation prices are biased away from the extremes however and sellers prices have positive autocorrelation and cross sectional correlation

the race between deterrence and displacement theory and evidence from bank robberies security measures that deter crime may unwittingly displace it to neighboring areas but evidence of displacement is scarce we exploit precise information on the timing and locations of all italia

sterilization of short term capital inflows through lower interest rates reductions in international interest rates are a major cause of capital flows to emerging economies increases in domestic interest rates are a frequent policy response to the resulting price increases this is often unsuccessful the paper suggests a theoretical explanation based on distinctive features of emerging financial markets including imperfect asset substitutability and imperfect capital mobility for some sectors of the economy it concludes that the appropriate policy response to capital inflows may be lower interest rates

casinos crime and community costs we examine the relationship between casinos and crime using county level data for the united states between 1977 and 1996 casinos were nonexistent outside nevada before 1978 and expanded to many other states during our sample period most factors that reduce crime occur before or shortly after a casino opens whereas those that increase crime including problem and pathological gambling occur over time the results suggest that the effect on crime is low shortly after a casino opens and grows over time roughly 8 of crime in casino counties in 1996 was attributable to casinos costing the average adult 75 per year

the dynamic instability of dispersed price equilibria abstract we adopt an evolutionary framework to explain price dispersion as a time varying phenomenon by developing a finite strategy analogue of the burdett and judd 1983 price dispersion model we show that all dispersed price equilibria are unstable under the class of perturbed best response dynamics instead numerical simulations using the logit dynamic show that price dispersion manifests itself as a limit cycle we verify that limit cycles persist even when the finite strategy model approaches the original continuous strategy model for a particularly simple case of the model we prove the existence of a limit cycle

learning mixed equilibria we study learning processes for finite strategic form games in which players use the history of past play to forecast play in the current period in a generalization of fictitious play we assume only that players asymptotically choose best responses to the historical frequencies of opponents past play this implies that if the stage game strategies converge the limit is a nash equilibrium in the basic model plays seems unlikely to converge to a mixed strategy equilibrium but such convergence is natural when the stage game is perturbed in the manner of harsanyi s purification theorem journal of economic literature classification number c72

inflation shoe leather costs and average inflation rates across countries abstract cross country differences in average inflation rates among 30 countries are well explained by differences in estimated shoe leather cost functions relating these costs to the inflation tax the shoe leather costs are estimated by means of the standard cagan semi log demand for real balances modified to take account of variations in reserve ratios and the effects of these variations on the demand for the monetary base the results are consistent with optimization on the part of an efficient government theory but are not adequate to discriminate between efficient government models and many others for which shoe leather costs play at least a substantial role in policy makers decisions the imposition of the semi log form does not seem critical in arriving at these conclusions although this form tends to produce more reasonable looking laffer surfaces than more flexible forms

public sector price increases credibility and welfare abstract this paper examines the dynamics of inflation and unemployment when the government increases public sector prices and wage indexation prevents the labor market from clearing in the short run credible reforms are virtually certain to be immediately deflationary and welfare improving even when the labor market clears very slowly temporary price increases however usually produce higher inflation after a short period of time and often reduce welfare when higher inflation provokes the government to reverse the reform there exist multiple self fulfilling equilibria

crime and the timing of work abstract two striking facts describe work timing in the united states a lower propensity to work evenings and nights in large metropolitan areas and a secular decline in such work since 1973 one explanation is higher and possibly increasing crime in large areas i link current population survey data on work timing to fbi crime reports neither fact is explained by changes in nor inter area differences in crime rates but higher homicide rates do reduce such work this reduction implicitly costs the economy between 4 and 10 billion this negative externality illustrates a larger class of previously unmeasured costs of social pathologies

functional form of the demand for real balances in cagan s hyperinflation model this paper uses recent advances in the development of testable implications of the cagan model of hyperinflation it extends the range of candidate functional forms of the demand for real balances in hyperinflations to include nonstandard versions in which the absolute inflation elasticity is a decreasing function of inflation these nonstandard functional forms are of interest because they are known to have desirable theoretical properties this paper finds empirical justification for a nonstandard form that performs at least as well as the traditional semilogarithmic functional form

is currency seigniorage exogenous for inflation tax in turkey this paper discusses the implications of the validity of the conditioning hypothesis for the maintained money demand equation for an inflation tax analysis we also test the validity of the quantity theoretical inflation tax model for the post 1980 quarterly turkish data by using johansen cointegration techniques the results suggest that the tax rate inflation is weakly exogenous for the parameters of the long run money demand tax base equation this result consistent with a keynesian endogenous seigniorage exogenous inflation tax rate theory prior does not support the hypothesis that the turkish inflation can be explained by the conventional inflation tax revenue maximizing motive alone