policy relevant treatment effects accounting for individual level heterogeneity in the response to treatment is a major development in the econometric literature on program evaluation a substantial body of empirical evidence demonstrates that econometric models fit on individual level data manifest heterogeneity in treatment effects that is present even after conditioning on observables an important distinction is the one between evaluation models where participation in the program being evaluated is based at least in part on unobserved idiosyncratic responses to treatment and models where participation is not based on unobserved idiosyncratic responses this is the distinction between selection on unobservables and selection on observables the validity of entire classes of evaluation estimators hinges on whether or not they allow agents to act on unobserved idiosyncratic responses in a wide variety of applications the available evidence suggests that not only are ex post postenrollment responses heterogeneous but that ex ante decisions to participate in programs are based in part on these heterogeneous responses heckman and vytlacil 2000b 2001

the empirical content of the roy model this paper clarifies and extends the classical roy model of self selection and earnings inequality the original roy model based on the assumption that log skills are normally distributed is shown to imply that pursuit of comparative advantage in a free market reduces earnings inequality compared to the earnings distribution that would result if workers were randomly assigned to sectors aggregate log earnings are right skewed even if one sectoral distribution is left skewed most major implications of the log normal roy model survive if differences in skills are log concave however few implications of the model survive if skills are generated from more general distributions we consider the identifiability of the roy model from data on earnings distributions the normal theory version is identifiable without regressors or exclusion restrictions sectoral distributions can be identified knowing only the aggregate earnings distribution for general skill distributions the model is not identified and has no empirical content with sufficient price variation the model can be identified from multimarket data cross sectional variation in regressors can substitute for price variation in restoring empirical content to the roy model

selection investment and women s relative wages over time in theory growing wage inequality within gender should cause women to invest more in their market productivity and should differentially pull able women into the workforce our paper uses heckman s two step estimator and identification at infinity on repeated current population survey cross sections to calculate relative wage series for women since 1970 that hold constant the composition of skills we find that selection into the female full time full year workforce shifted from negative in the 1970s to positive in the 1990s and that the majority of the apparent narrowing of the gender wage gap reflects changes in female workforce composition we find the same types of composition changes by measuring husbands wages and national longitudinal survey iq data as proxies for unobserved skills our findings help to explain why growing wage equality between genders coincided with growing inequality within gender

the demand for and impact of learning hiv status this paper evaluates an experiment in which individuals in rural malawi were randomly assigned monetary incentives to learn their hiv results after being tested distance to the hiv results centers was also randomly assigned without any incentive 34 percent of the participants learned their hiv results however even the smallest incentive doubled that share using the randomly assigned incentives and distance from results centers as instruments for the knowledge of hiv status sexually active hiv positive individuals who learned their results are three times more likely to purchase condoms two months later than sexually active hiv positive individuals who did not learn their results however hiv positive individuals who learned their results purchase only two additional condoms than those who did not there is no significant effect of learning hiv negative status on the purchase of condoms

micro data heterogeneity and the evaluation of public policy nobel lecture this paper summarizes the contributions of microeconometrics to economic knowledge four main themes are developed 1 microeconometricians developed new tools to respond to econometric problems raised by the analysis of the new sources of micro data produced after the second world war 2 microeconometrics improved on aggregate time series methods by building models that linked economic models for individuals to data on individual behavior 3 an important empirical regularity detected by the field is the diversity and heterogeneity of behavior this heterogeneity has profound consequences for economic theory and for econometric practice 4 microeconometrics has contributed substantially to the scientific evaluation of public policy

a multiplier decomposition method to analyze poverty alleviation abstract the objective of this paper is to present a multiplier decomposition method focusing on poverty alleviation the decomposition captures the various mechanisms and linkages through which a production sector s output contributes to poverty alleviation within a socioeconomic system represented by a social accounting matrix sam it is shown that a multiplier can be broken down into two multiplicative effects the distributional and interdependency effects the decomposition method is applied to the case of indonesia a key policy implication is that the human capital of the poor needs to be enhanced if they are not to be sealed off from the industrialization process

the estimation of wage gains and welfare gains in self selection models the authors modify the basic self sele ction model for the effects ofeducation training unions and other activities on wages by including heterogeneity of rewards to the activity i e diffe rences across individuals in the rate of return to the activity the authors sho w that such heterogeneity creates a new form of selectionbias they provide tes ts for its presence and draw out its implications for the wage and welfare gains to the activity an empirical application provides strong support for such hete rogeneityin one particular training program copyright 1987 by mit press

assessing the case for social experiments rs ecent academic debates pit two alternative approaches to policy evaluation against one another the first is the experimental approach based on the random assignment of accepted program applicants to a recipient or treatment group and a non recipient or control group the second is the nonexperimental or econometric approach that uses a variety of microdata sources statistical methods and behavioral models to compare the outcomes of participants in social programs with those of nonparticipants the central question addressed in this paper is whether or not randomized social experiments aid in securing answers to basic questions about the evaluation of social programs there are many distinct and complementary approaches to the study of the impact of public policy including full general equilibrium analysis of policy impacts tinbergen 1956 auerbach and kotlikoff 1987 shoven and whalley 1992 kydland and prescott 1991 and less ambitious partial equilibrium microeconomic structural research programs such as those designed to estimate the impact of taxes on labor supply both approaches offer answers to many interesting counterfactual policy questions but their credibility rests critically on the quality of the empirical input used to generate their answers

the effect of work experience on female wages and labour supply this paper develops and implements a semiparametric estimator for investigating with panel data the importance of human capital and time nonseparable preferences to females when aggregate shocks are present it provides a set of conditions for making statistical inferences about agents expectations of their correlated future choices from a short panel under the assumption that observed allocations are pareto optimal a dynamic model of female labour supply and participation is estimated in which experience on the job raises future wages and time spent off the job in the past directly affects current utility or indirectly through productivity in the nonmarket sector

the british low wage sector and the employment prospects of the unemployed abstractare low wages a way for the unemployed to switch to higher paying jobs using data from the british household panel survey the labour market dynamics of unemployed low paid and higher paid employed men are analysed moreover the respective un employment duration and occupational skill level are accounted for results show that in general low wages significantly reduce the risk of future unemployment and increase the chances of ascending the salary ladder especially in the case of long term unemployment 360 days furthermore the occupational skill level has a substantial influence on the upward mobility of low paid jobs individuals working in the initial period in a low paid and higher skilled occupation have on average an 11 percentage points higher probability of entering higher pay compared to when working in a low paid and low skilled occupation

the impacts of petroleum price fluctuations on income distribution across ethnic groups in malaysia crude oil price hikes have compelled governments of developing countries to let domestic prices of energy increase fiscal priorities made it impossible to fully compensate the hikes by raising energy subsidies this paper examines the potential impacts of a limited deregulation of the petroleum price on the income distribution in malaysia paying specific attention to differences in impacts on major ethnic groups we introduce an extended social accounting matrix sam model which not only incorporates substitution possibilities among production inputs and consumption goods but also allows for the exogenous determination of the price of intermediate inputs the results of simulations indicate that distributional impacts of rising petroleum prices tend to be regressive affecting poor people more severely than richer people all ethnic groups experience income loss with the real incomes of malay households which are relatively poor on average more than the chinese and indian households which are the generally richer

an empirical model of labor supply in a life cycle setting this paper formulates and estimates a structural intertemporal model of labor supply using theoretical characterizations derived from an economic model of lifetime behavior a two step empirical analysis yields estimates of intertemporal and uncompensated substitution effects which provide the information needed to predict the response of hours of work to life cycle wage growth and shifts in the lifetime wage path

viewpoint estimating the causal effects of policies and programs estimation inference and interpretation of the causal effects of programs and policies have all advanced dramatically over the past 25 years we highlight three particularly important intellectual trends an improved appreciation of the substantive importance of heterogeneous responses and of their methodological implications a stronger focus on internal validity brought about by the credibility revolution and the scientific value that follows from grounding estimation and interpretation in economic theory we discuss a menu of commonly employed partial equilibrium approaches to the identification of causal effects emphasizing that the researcher s central intellectual contribution always consists of making an explicit case for a specific causal interpretation given the relevant economic theory the data the institutional context and the economic question of interest we also touch on the importance of general equilibrium effects and full cost benefit analyses

a reappraisal of the virtues of private sector employment programmes in this paper we evaluate the employment effects of danish active labour market programmes aimed at welfare benefits recipients we estimate an econometric model with treatment effects and discrete outcomes and we allow the responses to treatment to vary among observationally identical persons the empirical analysis is based on a register based dataset that gives information on participation in labour market programmes and subsequent employment using a latent variable model we estimate commonly defined treatment effects and in particular the distribution of treatment effects we do not find any significant mean effects of participation in private sector employment programmes compared to participation in other programmes but we find evidence of heterogeneity in the treatment effects

evaluating the effects of childcare policies on children s cognitive development and maternal labor supply to explore the role of childcare policies in the development of early cognitive skills this paper jointly estimates a cognitive achievement production function and a dynamic discrete choice model of maternal labor supply and childcare decisions using counter actuals from the model i investigate how the designs of two childcare programs head start and childcare subsidies affect the formation of cognitive skills through maternal work and childcare decisions the results suggest large impacts on cognitive skills from expanding head start to current noneligibles and negligible impacts of subsidies on cognitive skills of current eligibles abstract from author

on using linear regressions in welfare economics this article consists of two parts the first part shows that the ordinary least squares regression coefficient is a weighted average of slopes between adjacent sample points when applied to a linear regression with income as the independent variable the regression coefficient depends heavily on the slopes of high income groups the weight of the highest income decile may well exceed that of the other nine deciles this may be undesirable especially if the regression is used for welfare analysis because the marginal propensities to consume attributed to the commodities are determined by the high income groups the second part of the article proposes alternative estimators the extended gini estimators that enable investigators to control the weighting scheme and to incorporate their social views into the weighting scheme of the estimators

fast food consumption and the ban on advertising targeting children the quebec experience abstract amid growing concerns about childhood obesity and the associated health risks several countries are considering banning fast food advertising targeting children in this article the authors study the effect of such a ban in the canadian province of quebec using household expenditure survey data from 1984 to 1992 authors examine whether expenditure on fast food is lower in those groups affected by the ban than in those that are not the authors use a triple difference indifference methodology by appropriately defining treatment and control groups and find that the ban s effectiveness is not a result of the decrease in fast food expenditures per week but rather of the decrease in purchase propensity by 13 per week overall the authors estimate that the ban reduced fast food consumption by us 88 million per year the study suggests that advertising bans can be effective provided media markets do not overlap

real wages over the business cycle evidence from panel data one topic on which keynes did not disagree with classical economists was the cyclical behavior of real wages keynes 1936 as well as various classical writers predicted that real wages should move countercyclically quoting the general theory p 17 in general an increase in employment can only occur through the accompaniment of a decline in real wages thus i am not disputing this vital fact which the classical economists have rightly asserted as indefeasible this prediction is based on the premise of competition and a given short run capital stock increases in employment then correspond to more intensive use of capital and through diminishing product lower real wages for this reason evidence by dunlop 1938 and tarshis 1939 that real wages move procyclically was viewed as paradoxical both dunlop and tarshis based their findings on an observed positive correlation between real and money wages which given the procyclical movement of money wages implies a positive correlation between

modeling heterogeneous farm responses to european union biofuel support with a random parameter multicrop model although there is now widespread evidence of substantial variability in economic agents responses to economic drivers in many applied economics fields this variability has been largely overlooked by econometric agricultural production models this article sets out to fill this gap by providing methodological contributions and empirical results first we consider panel data multicrop models featuring random intercept and slope parameters to account for the heterogeneous responses of crop producers to economic drivers second we show that monte carlo expectation maximization algorithms are particularly well suited to estimating this type of model third based on an application of our empirical modeling framework with a sample of french grain crop producers we demonstrate substantial variability in farmers responses to economic incentives fourth we use the estimated model and a simple statistical calibration procedure to build farm specific simulation models which are then used to evaluate the effects of the rapeseed price increase induced by european union eu biofuel support our simulation results demonstrate that ignoring the variability in the considered farmers responses to the economic incentives results in significant overestimation of the increases in rapeseed yield levels and variable input use levels induced by eu biofuel support as well as significant underestimation of the variability in the congruent increases in rapeseed acreages

what has been learned about labor supply in the past twenty years the main advance in the study of labor supply in the past 20 years has come in recognizing and interpreting the variety of different labor supply functions that coexist in the empirical literature a crucial theoretical distinction with important empirical payoff is that between labor supply choices at the extensive margin i e labor force participation and employment choices and choices at the intensive margin i e choices about hours of work or weeks of work for workers another important distinction is the one between a descriptive labor supply function and a structural supply function that can be the basis for out of sample policy investigations concerning responses to tax and welfare programs and evaluations of welfare losses a full understanding of the participation hours dichotomy leads to an appreciation of the importance of the problem of selection bias what is the wage to impute to a nonworking person these distinctions are a legacy of the research conducted on labor supply over the past 20 years many important empirical questions have been addressed i how strong are the effects of taxes welfare and transfer programs on labor supply ii how important is intertemporal substitution can life cycle labor supply models explain business cycle labor supply behavior iii has the consensus view of the 1960 s of high labor supply elasticities for married women and low labor supply elasticities for married men held up all of the empirical evidence assembled on labor supply must be called into question in the light of important research on the basic quality of the data conducted by analysts at the university of michigan i discuss this evidence in a concluding section except for my discussion of measurement issues i focus only on the major discoveries about which a general consensus has emerged

beyond publication bias abstract this review considers several meta regression and graphical methods that can differentiate genuine empirical effect from publication bias publication selection exists when editors reviewers or researchers have a preference for statistically significant results because all areas of empirical research are susceptible to publication selection any average or tally of significant insignificant studies is likely to be biased and potentially misleading meta regression analysis can see through the murk of random sampling error and selected misspecification bias to identify the underlying statistical structures that characterize genuine empirical effect meta significance testing and precision effect testing pet are offered as a means to identify empirical effect beyond publication bias and are applied to four areas of empirical economics research minimum wage effects union productivity effects price elasticities and tests of the natural rate hypothesis

growing up in the projects the economic lives of a cohort of men who came of age in chicago public housing empirical research by labor economists relies overwhelmingly on data collected in largescale government funded surveys the availability of such data dramatically lowers the cost of conducting research for any individual scholar large sample sizes and extensive breadth of variables allow precise testing of a wide variety of hypotheses combined with enormous increases in computing capabilities and the development of new techniques to analyze such data these data sets have transformed the field of labor economics james heckman 2000 the use of large scale survey data however has not come without a cost the set of questions that can be addressed is constrained by the variables that have been collected these studies are typically nationally representative with sample sizes too small to undertake detailed analysis in particular localized geographic areas or very specific subsets of the overall population because the researcher is removed from the data collection process and the analysis is national in focus understanding of institutional detail is de emphasized ethnography used by sociologists and anthropologists represents the polar opposite of the standard economic approach an ethnographer integrates himself or herself into the community being analyzed paying careful attention to the context in which the actors operate such studies tend to rely almost exclusively on qualitative analysis rarely gathering systematic quantitative data the benefits to such an approach are that the researcher structures the analysis to answer precisely the desired question and the depth of specific knowledge acquired by the sociologist allows for a richer understanding of the problem the costs of such an approach are that it is time intensive cannot be replicated and is of questionable generalizability in this paper we report preliminary findings of a joint study undertaken by an economist and an ethnographer that aims to integrate the usual economic and ethnographic approaches to empirical research 1 focusing on the residents of one high rise housing project building in chicago we have attempted to reconstruct retrospectively the economic and social histories of all young males who spent their adolescence in the housing project in the early 1990 s through the use of an extensive net of community contacts we have to date succeeded in locating 105 of these 118 men who are now in their late twenties and early thirties for almost all of these men we have obtained not only extensive self reported information but also evaluations of these men by other community members on a wide range of characteristics

meta analysis of economics research reporting guidelines meta regression analysis mra can provide objective and comprehensive summaries of economics research their use has grown rapidly over the last few decades to improve transparency and to raise the quality of mra the meta analysis of economics research network maer net has created the below reporting guidelines future meta analyses in economics will be expected to follow these guidelines or give valid reasons why a meta analysis must deviate from them

the joint determination of union status and union wage effects some tests of alternative models the problems of estimation and interpretation of union wage differentials are examined the properties of cross section and longitudinal estimators are compared estimates are presented and those in the literature summarized conflicting results are obtained longitudinal estimators typically produce results smaller than those of ols while cross section methods instrumental variables or inverse mills ratio raise the estimate the paper offers a reconciliation of these results it supports a more optimistic conclusion than that reached in reviews by freeman and lewis who argued that little has been learned from attempts to deal with the endogeneity issue comparisons between estimators are used to throw light on the process governing union status and to suggest interpretations of union differentials consistent with the current evidence

education s role in china s structural transformation abstract we explore education s role in improving the allocation of labor between china s agricultural and nonagricultural sectors and measure the portion of china s recent growth attributable to this channel using detailed micro level data and an empirical model that allows for the endogenous selection of education and sector of employment we estimate the relationship between an individual s educational attainment sector and income we find that about 11 of aggregate growth in output per worker from 1978 to 2004 is accounted for by increased education with 9 coming through the labor reallocation channel and 2 attributable to increased within sector human capital

can higher prices stimulate product use evidence from a field experiment in zambia the controversy over how much to charge for health products in the developing world rests in part on whether higher prices can increase use either by targeting distribution to high use households a screening effect or by stimulating use psychologically through a sunk cost effect we develop a methodology for separating these two effects we implement the methodology in a field experiment in zambia using door to door marketing of a home water purification solution we find evidence of economically important screening effects by contrast we find no consistent evidence of sunk cost effects jel c93 d12 i11 m31 o12

the interpretation of instrumental variables estimators in simultaneous equations models with an application to the demand for fish in markets where prices are determined by the intersection of supply and demand curves standard identification results require the presence of instruments that shift one curve but not the other these results are typically presented in the context of linear models with fixed coefficients and additive residuals the first contribution of this paper is an investigation of the consequences of relaxing both the linearity and the additivity assumption for the interpretation of linear instrumental variables estimators without these assumptions the standard linear instrumental variables estimator identifies a weighted average of the derivative of the behavioural relationship of interest a second contribution is the formulation of critical identifying assumptions in terms of demand and supply at different prices and instruments rather than in terms of functional form specific residuals our approach to the simultaneous equations problem and the average derivative interpretation of instrumental variables estimates is illustrated by estimating the demand for fresh whiting at the fulton fish market strong and credible instruments for identification of this demand function are available in the form of weather conditions at sea

indivisible labor lotteries and equilibrium abstract this paper considers an economy where labor is indivisible and agents are identical although the discontinuity in labor supply at the individual level disappears as a result of aggregation it is shown that indivisible labor has strong consequences for the aggregate bahavior of the economy it is also shown that optimal allocations involve lotteries over employment and consumption

rationality of migration the paradigm of a rational individual acting on the earnings enhancing benefits of migration is subjected to statistical scrutiny using data from turkey results with robust selectivity correction support the rationality hypothesis both migrants and nonmigrants chose the option in which they had comparative advantage however the estimated gain from moving is negative for a substantial portion of migrants whereas a minority realize very high returns this suggests that migration is a lottery individuals are willing to invest in a proposition that has a high probability of yielding negative returns because of the potential for a very large payoff

general equilibrium treatment effects a study of tuition policy this paper defines and estimates general equilibrium treatment effects the conventional approach in the literature on treatment effects ignores interactions among individuals induced by the policy interventions being studied focusing on the impact of tuition policy and using estimates from our dynamic overlapping generations general equilibrium model of capital and human capital formation we find that general equilibrium impacts of tuition on college enrollment are an order of magnitude smaller than those reported in the literature on microeconomic treatment effects the assumptions used to justify the late parameter in a partial equilibrium setting do not hold in a general equilibrium setting policy changes induce two way flows we extend the late concept to a general equilibrium setting we present a more comprehensive evaluation to program evaluation by considering both the tax and benefit consequences of the program being evaluated and placing the analysis in a market setting this abstract was borrowed from another version of this item

do wage subsidies increase employment in subsidized firms this paper examines whether subsidized jobs have contributed to employment in subsidized firms or have merely substituted for non subsidized ones the data set is an unbalanced panel of some 31 000 firms that are followed annually between 1995 and 2002 the analysis is based on difference in differences which is adjusted by regression and matching methods the results indicate that wage subsidies stimulate employment and that the magnitude of the effect is as aimed i also found that subsidies have no sizeable effects on non subsidized firms

indivisible labor and the business cycle abstract a growth model with shocks to technology is studied labor is indivisible so all variability in hours worked is due to fluctuations in the number employed we find that unlike previous equilibrium models of the business cycle this economy displays large fluctuations in hours worked and relatively small fluctuations in productivity this finding is independent of individuals willingness to substitute leisure across time this and other findings are the result of studying and comparing summary statistics describing this economy an economy with divisible labor and post war u s time series

reconciling conflicting evidence on the performance of propensity score matching methods there is a long standing debate in the literature over whether social programs can be reliably evaluated without a randomized experiment this paper summarizes results from a larger paper smith and todd 2001 that uses experimental data combined with nonexperimental data to evaluate the performance of alternative nonexperimental estimators the impact estimates based on experimental data provide a benchmark against which to judge the performance of nonexperimental estimators our experimental data come from the national supported work nsw demonstration and the nonexperimental data from the current population survey cps and the panel study of income dynamics psid these same data were used in influential papers by robert lalonde 1986 james heckman and joseph hotz 1989 and rajeev dehejia and sadek wahba 1998 1999 we focus on a class of estimators called propensity score matching estimators which were introduced in the statistics literature by paul rosenbaum and donald rubin 1983 traditional propensity score matching methods pair each program participant with a single nonparticipant where pairs are chosen based on the degree of similarity in the estimated probabilities of participating in the program the propensity scores more recently developed nonparametric matching estimators described in heckman et al 1997 1998a b use weighted averages over multiple observations to construct matches we apply both kinds of estimators in this paper heckman et al 1997 1998a b evaluate the performance of matching estimators using experimental data from the u s national job training partnership act jtpa study combined with comparison group samples drawn from three sources they show that data quality is a crucial ingredient to any reliable estimation strategy specifically the estimators they examine are only found to perform well in replicating the results of the experiment when they are applied to comparison group data satisfying the following criteria i the same data sources i e the same surveys or the same type of administrative data or both are used for participants and nonparticipants so that earnings and other characteristics are measured in an analogous way ii participants and nonparticipants reside in the same local labor markets and iii the data contain a rich set of variables relevant to modeling the program participation decision if the comparison group data fails to satisfy these criteria the performance of the estimators diminishes greatly more recently dehejia and wahba 1998 1999 have used the nsw data also used by lalonde to evaluate the performance of propensity score matching methods including pairwise matching and caliper matching they find that these simple matching estimators succeed in closely replicating the experimental nsw results even though the comparison group data do not satisfy any of the criteria found to be important in heckman et al 1997 1998a from this evidence they conclude that matching approaches are generally more reliable than traditional econometric estimators in this paper we reanalyze the nsw data in an attempt to reconcile the conflicting findings smith department of economics university of western ontario social science centre london on n6a 5c2 canada and nber todd department of economics university of pennsylvania 3718 locust walk philadelphia pa 19104 and nber versions of the paper that is the source for this paper have been presented at a 2000 meeting of the institute for research on poverty in madison wisconsin at the western research network on employment and training summer workshop august 2000 at the canadian international labour network meetings september 2000 and at the university of north carolina we thank james heckman for comments on this paper and we thank robert lalonde for comments and for providing us with the data from his 1986 study we thank rajeev dehejia for providing us with information helpful in reconstructing the samples used in the dehejia and wahba 1998 1999 studies jingjing hsee and miana plesca provided excellent research assistance

price knowledge in household demand for utility services a household s decision to acquire price knowledge is endogenous in the demand for utility services and may affect elasticities and consumption levels a simultaneous equation model with endogenous switching is developed to evaluate the effects of price knowledge and other sources of heterogeneity results indicate informed households were more responsive to average and marginal price signals informed households also use less water but this is due to heterogeneity rather than price knowledge controlling for heterogeneity price knowledge actually increases monthly water usage the implications of accounting for differences in price knowledge in utility demand modeling and demand management policy are discussed

the employment effects of an income redistribution in developing countries the 1970 ilo mission report to colombia first proposed the notion that since the poor tend to consume a more labour intensive basket of commodities than the rich a redistribution of income in their favour will tend to increase employment this proposal gave rise to a host of attempts in the 1970s to demonstrate its empirical validity in a number of developing countries the results however provided only a very limited degree of support to the ilo hypothesis indeed by 1978 the clear conclusion of the general equilibrium macroeconomic models was that income redistribution would have only a tiny effect on employment 1

evaluating the econometric evaluations of training programs with experimental data this paper takes the results of an employment and training program thatwas run as a field experiment in which the participants were randomlyassigned into a treatment or a control group and compares these results to the estimates that might have been produced by an econometrician who evaluated the program using the same econometric procedures that have been used in the program evaluation literature this comparison shows that many of these econometric procedures fail toreplicate the experimentally determined results and suggests that researchers should be aware of the potential for specification errorsin other nonexperimental evaluations copyright 1986 by american economic association

heterogeneity and the non parametric analysis of consumer choice conditions for invertibility this paper considers structural non parametric random utility models for continuous choice variables with unobserved heterogeneity we provide sufficient conditions on random preferences to yield reduced form systems of non parametric stochastic demand functions that allow global invertibility between demands and non separable unobserved heterogeneity invertibility is essential for global identification of structural consumer demand models for the existence of well specified probability models of choice and for the non parametric analysis of revealed stochastic preference we distinguish between new classes of models in which heterogeneity is separable and non separable in the marginal rates of substitution respectively

econometrics of first price auctions in this paper we propose an estimation method for the empirical study of theoretical auction models we focus on first price sealed bid and descending auctions and we adopt the private value paradigm where each bidder is assumed to have a different private value only known to him for the object that is auctioned following mcfadden 1989 and pakes and pollard 1989 our proposed method is based on simulations specifically the method relies on a simulated nonlinear least squares objective function appropriately adjusted so as to obtain consistent estimates of the parameters of interest we illustrate the proposed method by studying a market of agricultural products where descending auctions are used our analysis takes into account heterogeneity of the auctioned objects and the fact that only the winning bid is observed we estimate the parameters that characterize the distribution of the unobserved private values for each auctioned object

technology choice and income distribution within the context of the agricultural sector one can point to numerous attempts to assess the macro economic effects of alternative technologies on the distribution of income one of the most influential early efforts for example was undertaken mainly in the indian context by john mellor 1 who was seeking to redefine agriculture s role in development strategy and policy in rejecting the then existing capital intensive and industry led development model and advocating instead a rural led employment intensive path to development mellor was concerned among other things with the relationships between increased foodgrain production using alternative technologies and the growth rate of non agricultural employment non agricultural sector capital labour ratios and the course of per capita incomes of the labour force more recently haggblade and hazell2 have used an input output based model to examine how differences in the choice of agricultural technology and farm size influence the indirect or multiplier effects of increases in agricultural output they show for example that the input intensity consumption profile of targeted farms and processing characteristics of the farm output all affect the size and composition of nonfarm spinoffs 3 the finding that consumption linkages generally dominate the total multiplier confirms mellor s emphasis on the importance of this particular type of linkage effect

the displacement effect of reemployment bonus programs we develop a partial equilibrium matching model of the labor market in order to examine whether adoption of a reemployment bonus would displace workers not offered the bonus we examine the displacement effect for a unemployment insurance ui eligible workers who are offered but do not find a job in time to qualify for a bonus and b ui ineligible workers who are never offered a bonus the model predicts minimal displacement of the former group but for the latter group the model predicts an increase in unemployment duration of 2 4 week and an increase in unemployment of up to 2 per thousand

price versus quantity monitoring in an adverse selection context this article explores the relative usefulness of price information over quantity information the main finding is that price monitoring can induce a sales level that is greater than the full information sales level this imposes additional selling costs on the agent and reduces that agent s rents the analysis identifies sufficient conditions for the principal to prefer price monitoring over quantity monitoring business format franchises exhibit many of the features of the setting analyzed here and the article s findings have implications for designing information systems in that sector of the economy

does the size of the legislature affect the size of government evidence from two natural experiments this paper makes use of regression discontinuity designs to estimate the effect of the number of legislators on the size of government the results indicate a negative effect i e the larger the size of the legislature the smaller is the size of government this runs counter to conventional wisdom one potential explanation is that more legislators can better control a budget maximizing bureaucracy i present evidence that is consistent with the proposed mechanism

sequential migration theory and evidence from peru abstract the standard human capital model of labor migration has been successful in explaining several empirical regularities of the migration process however there are a number of empirical facts that have not yet been explained or empirically tested among them that migrants usually perform more than one move in their lifetime return migration accounts for a very important share of total migration rates and there is a high positive correlation between in and out migration rates in the more advantageous regions this paper presents both a simple model explaining these facts and an empirical analysis using data from peru

life cycle schooling and dynamic selection bias models and evidence for five cohorts of american males this paper examines an empirical regularity found in many societies that family influences on the probability of transiting from one grade level to the next diminish at higher levels of education we examine the statistical model used to establish the empirical regularity and the intuitive behavioral interpretation often used to rationalize it we show that the implicit economic model assumes myopia the intuitive interpretive model is identified only by imposing arbitrary distributional assumptions onto the data we produce an alternative choice theoretic model with fewer parameters that rationalizes the same data and is not based on arbitrary distributional assumptions

dynamic labour force participation of married women and endogenous work experience this paper presents and estimates a dynamic model of married women s labour force participation and fertility in which the effect of work experience on wages is explicitly taken into account because current participation alters future potential earnings the investment return to work will be an important factor in the current work decision in any forward looking behavioural model the model is estimated using the national longitudinal surveys mature women s cohort we use the estimates of our model to predict changes in the lifecycle patterns of employment due to changes in schooling fertility husband s income and the magnitude of the experience effect on wages we find that although work experience increases the disutility of further work the effect is overwhelmed by the positive effect of experience on wages leading to persistence in the employment patterns of these women in addition we find that an increase in young children and in husband s income substantially reduces participation while increased schooling has a powerful positive impact on participation this paper presents an estimable structural dynamic model of married women s labour force participation and fertility in which wages are stochastic and work experience or cumulative participation is endogeneous the model is structural in the sense that the parameters which are estimated are contained in the fundamental relationships governing behaviour namely the utility function and the constraints the model is contained in the class of models which describe the life cycle capital accumulation process with endogeneous labour supply such as weiss 1972 and heckman 1976 it is closest in spirit to that of weiss and gronau 1981 1 the basic feature of their model and ours is that labour market participation affects future wages which then affects future participation the investment return to current work will necessarily be taken into account in any forward looking optimizing model as weiss and gronau note estimates of labour supply models have ignored the inherent behavioural dynamics associated with a positive wageexperience profile there is no adequate empirical treatment of the human capital investment dimension of the labour force participation decision in the literature heckman and willis 1977 have studied a sequential discrete choice model of the labour force participation of married women in a reduced form framework their work

income and consumption a micro semistructural analysis with pervasive heterogeneity we develop a model of consumption and income that allows for pervasive heterogeneity in the parameters of both processes introducing codependence between household income parameters and preference

linkages among welfare food assistance programmes and labour supply evidence from the survey of programme dynamics at the centre of the debate on welfare reform is whether incentives based systems help poor families move out of poverty into jobs recent data from the first survey of programme dynamics longitudinal and the 1998 experimental data files allow evaluation of the interaction among the food stamp programme fsp temporary assistance for needy families tanf programme and labour force participation under different programme design and economic conditions a model that incorporates jointly determined programmes participation and work decisions is applied to a sample of working age lower income and asset households participation in tanf increases the probability of fsp participation and decreases the probability of being in the work force working decreases the probability of receiving food stamps work tanf and fsp participation are related and tanf and fsp participation rates among poor households who are potentially eligible for tanf are sensitive to changes in programme parameters as expected labou

the endogeneity of union status an empirical test an unsettled issue in the literature relating to the relative wage effect of unions is the appropriate treatment of union status in a wage determination model in the context of a three equation model determining union membership and union and nonunion sector wage rates this paper presents an instrumental variables iv procedure for estimating the parameters of the wage equations and a test of the exogeneity of union status using the hausman specification test an advantage of our iv procedure in comparison to the widely used inverse mill s ratio procedure is that our procedure is a distribution free estimator whereas the inverse mill s ratio estimator hinges in the assumption that the error term of the choice equation is normally distributed using data for a sample of middle aged white workers we estimate the parameters of the union and nonunion wage equations with both procedures on the key question of the endogeneity of union status the hausman test decisively rejects the null hypothesis of exo

allocation of human capital and innovation at the frontier firm level evidence on germany and the netherlands this paper examines how productivity eects of human capital and innovation vary at dierent points of the conditional productivity distribution our analysis draws upon two large unbalanced panels of 6 634 enterprises in germany and 14 586 enterprises in the netherlands over the period 2000 2008 considering 5 manufacturing and services industries that dier in the level of technological intensity industries in the netherlands are characterized by a larger average proportion of high skilled employees and indus tries in germany by a more unequal distribution of human capital intensity except for low technology manufacturing average innovation performance is higher in all industries in germany and the innova tion performance distributions are more dispersed in the netherlands in both countries we observe non linearities in the productivity eects of investing in product innovation in the majority of indus tries frontier rms enjoy the highest returns to product innovation whereas the most negative returns to process innovation are observed in the best performing enterprises of most industries in both countries we nd that the returns to human capital increase with proximity to the technological frontier in industries with a low level of technological intensity strikingly a negative complementarity eect between human capital and proximity to the technological frontier is observed in knowledge intensive services which is most pronounced for the netherlands suggestive evidence for the latter points to a winner takes all interpretation of this nding

black white earnings ratios since the civil rights act of 1964 the importance of labor market dropouts published median earnings of wage and salary workers by race and sex are based on distributions that exclude those without earnings and those not employed as wage and salary workers at the time of the survey it has been argued that the changing importance of these exclusions rather than any improvement in the distribution of offered wages for blacks accounts for the apparent increase in black white relative median earnings this paper presents a new method for correcting the published medians for such censoring the apparent improvement in relative earnings is reduced but not eliminated by the correction

tax policy and human capital formation missing from recent discussions of tax reform is any systematic analysis of the effects of various tax proposals on skill formation this gap in the literature in empirical public finance is due to the absence of any empirically based general equilibrium models with both human capital formation and physical capital formation that are consistent with observations on modern labor markets this paper is a progress report on our ongoing research on formulating and estimating dynamic general equilibrium models with endogenous heterogeneous human capital accumulation our model explains many features of rising wage inequality in the u s economy james heckman lance lochner and christopher taber 1998 in this paper we use our model to study the impacts on skill formation of proposals to switch from progressive taxes to flat income and consumption taxes for the sake of brevity we focus on steady states in this paper although we study both transitions and steady states in our research this abstract was borrowed from another version of this item

further evidence of excess sensitivity of consumption nonseparability among goods and heterogeneity across households the standard theoretical framework for analysing households intertemporal decisions is the life cycle permanent income model among its implications testing the model allows to analyse the response of consumption to fiscal policy however the empirical literature with microdata has yielded mixed results this article examines the sensitivity of the results to the assumption of separability among goods and of homogeneity across households for that purpose we test a rational expectations permanent income model with household data drawn from the spanish family expenditure survey this survey contains detailed information on total expenditure and the income presents large exogenous quarterly changes due to an institutional feature the article shows that assuming separability among commodities biases the test against the model when separability is not imposed we show that the rejection of the model depends on heterogeneity across households in terms of their members being unemployed or not for those

true and spurious duration dependence the identifiability of the proportional hazard model lancaster and nickell 1980 have argued that in the proportional hazard model the effects of time dependence true duration dependence and unobserved sample heterogeneity spurious duration dependence cannot be distinguished we show that both effects can be distinguished if the model allows for observed explanatory variables in the hazard we also discuss the application of our result to practical situations

sectoral growth and poverty alleviation a multiplier decomposition technique applied to south africa abstract how does an increase in a sector s output affect poverty alleviation in this paper a multiplier decomposition for a socioeconomic system represented by a social accounting matrix sam is used to study this linkage the decomposition applied to south africa reveals that growth in agriculture services and some manufacturing sectors can alleviate poverty for the black african population for sectoral growth to be effective however the need for appropriate skill acquisition for the poor must be addressed directly only long term policies geared towards improving both economic growth and the human capital stock of the poor can lead to significant poverty alleviation

household choices in equilibrium this paper is an empirical investigation of equilibrium restrictions on household consumption and male labor supply it exploits a simple factor structure rationalized by two assumptions that household allocations are pareto optimal and that the labor market is competitive the paper estimates household preferences and tests how well this parsimonious factor structure represents panel data on married couples and time series data on asset returns most of the estimates are roughly comparable to those found in previous work no evidence against the simple factor representation is found and the intertemporal capital asset pricing model is not rejected copyright 1990 by the econometric society

accounting for heterogeneity in multicrop micro econometric models implications for variable input demand modeling this article aims to show that if the farm sample under consideration is characterized by significant heterogeneity recovering output specific input uses or modeling farm level input uses may be more complicated than previously recognized the article theoretically investigates the problems implied by farm heterogeneity in input allocation equations and multicrop econometric models proposes an empirically tractable solution for overcoming these problems and assesses the empirical relevance of the theoretically identified problems the results demonstrate that heterogeneity matters but that the revealed heterogeneity bias has a limited impact on the empirical results copyright 2012 oxford university press

self selection and the distribution of hourly wages this article formulates and estimates alternative equilibrium models of industrial wage determination and self selection in explaining industrial wage differentials we find that it is important to account for heterogeneous sector specific skills and self selection decisions by agents concerning their sector of employment the classical roy model is rejected so is an efficiency units model of the labor market a revised roy model that accounts for comparative advantage in the choice of industrial sectors and choice between market and nonmarket work is much more successful in explaining cross section wage distributions and their evolution over time

an estimable dynamic general equilibrium model of work schooling and occupational choice this paper develops and estimates a dynamic general equilibrium overlapping generations model of career decisions the model is fit to data on life cycle employment schooling and occupation decisions and on life cycle labor earnings within and between cohorts observed in the us between 1968 and 1993 based on the estimates of the model the impact of cohort size on skill prices and consequently on career decisions is assessed compared to a baseline case in which cohort size increased at a steady average rate and the fertility process was stationary it is found that the male baby bust generations born in the 1930s and 1940s faced higher skill prices by as much as 2 0 completed college at a higher rate by as much as 0 3 percentage points and worked more over the lifetime by as much as 0 1 years in contrast the males from the baby boom generations born in the 1950s and 1960s faced lower skill prices by as much as 1 5 completed college at a lower rate by as much as 1 0 percentage points and worked less over the lifetime by as much as 0 1 years the impact of cohort size is found to differ across gender due to the differential impact of fertility on the value of home production unlike males the female baby bust generations completed college at a lower rate by as much as 1 5 percentage points and worked less over the lifetime by as much as 0 5 years while the female baby boom generations completed college at a lower rate by as much as 1 5 percentage points and worked more over the lifetime by as much as 0 2 years a tuition subsidy experiment is also performed both in a general equilibrium setting in which skill prices are endogenous and in a partial equilibrium setting with fixed skill prices based on the estimated model a 1 increase in tuition is predicted to reduce college enrollment rates by 1 27 in partial equilibrium consistent with previous estimates and by 1 05 in the general equilibrium case thus for this policy experiment the partial equilibrium analysis of schooling choice would not differ significantly from the general equilibrium analysis

the composition of growth matters for poverty alleviation this paper contributes to explain the cross country heterogeneity of the poverty response to changes in economic growth it does so by focusing on the structure of output growth the paper presents a two sector theoretical model that clarifies the mechanism through which the sectoral composition of growth and associated labor intensity can affect workers wages and thus poverty alleviation then it presents cross country empirical evidence that analyzes first the differential poverty reducing impact of sectoral growth at various levels of disaggregation and the role of unskilled labor intensity in such differential impact the paper finds evidence that not only the size of economic growth but also its composition matters for poverty alleviation with the largest contributions from labor intensive sectors such as agriculture construction and manufacturing the results are robust to the influence of outliers alternative explanations and various poverty measures

determinants of successful regional trade agreements abstract this paper investigates the determinants of the effectiveness of regional trade agreements rtas in enhancing bilateral trade characteristics of both the country pair and other rta members are found to significantly influence the trade creation effect of rtas however north north north south and south south rtas are found to have similar effects on trade

patents as options some estimates of the value of holding european patent stocks in many countries holders of patents must pay an annual renewal fee in order to keep their patents in force this paper uses data on the proportion of patents renewed and the renewal fees faced by post world war ii cohorts of patents in france the united kingdom and germany in conjunction with a model of patent holders renewal decisions to estimate the returns earned from holding patents in these countries since patents are often applied for at a nearly stage in the innovation process the model allows agents to be uncertain about the sequence of returns that will be earned if the patent is kept inforce formally then the paper presents and solves a discrete choice optimal stochastic control model derives the implications of the model on aggregate behaviour and then estimates the parameters of the model from aggregate data the estimates enable a detailed description of the evolution of the distribution of returns earned from holding patents over their life spans and calculations of both the annual returns earned from holding the patents still in force or the patent stocks in the alternative countries and the distribution of the discounted value of returns earned from holding the patents in a cohort this abstract was borrowed from another version of this item

poverty in bangladesh measurement decomposition and intertemporal comparison this article using the methodology developed by foster greer and thorbecke to measure and decompose poverty provides estimates of the levels of poverty in rural and urban areas in bangladesh it investigates in the context of bangladesh the most powerful effect of poverty in terms of a shortfall in food for daily calorie intake by the poor it provides intertemporal comparison of poverty and its decomposition among subgroups it also makes comparisons between the results obtained in this study with those currently available the results of the study show a significant improvement in poverty situations in rural areas from 1982 to 1986 the article also discusses the policy implications of its findings

understanding black white wage differentials 1960 1990 understanding black white wage differentials 1960 1990 author s james j heckman thomas m lyons petra e todd source the american economic review vol 90 no 2 papers and proceedings of the one hundred twelfth annual meeting of the american economic association may 2000 pp 344 349 published by american economic association stable url http www jstor org stable 117248 accessed 16 08 2008 00 56

identification of standard auction models this paper presents new identification results for models of first price second price ascending english and descending dutch auctions we consider a general specification of the latent demand and information structure nesting both private values and common values models and allowing correlated types as well as ex ante asymmetry we address identification of a series of nested models and derive testable restrictions enabling discrimination between models on the basis of observed data the simplest model symmetric independent private values is nonparametrically identified even if only the transaction price from each auction is observed for richer models identification and testable restrictions may be obtained when additional information of one or more of the following types is available i the identity of the winning bidder or other bidders ii one or more bids in addition to the transaction price iii exogenous variation in the number of bidders iv bidder specific covariates while many private values pv models are nonparametrically identified and testable with commonly available data identification of common values cv models requires stringent assumptions nonetheless the pv model can be tested against the cv alternative even when neither model is identified

the length of stay in the demand for tourism abstract one of the main characteristics of current tourism is the reduction in the length of stay at a destination nevertheless this variable has received little attention in literature this paper examines the microeconomic determinants of the length of stay at one of the mediterranean s leading sun and sand destinations the estimation of a conditional demand function model highlights the explanatory power of the tourist s sociodemographic profile and of holiday characteristics as well as the sensitivity of the length of stay to price changes

the sectoral structure of poverty during an adjustment period evidence for indonesia in the mid 1980s the authors examine the structure of poverty in indonesia by sector of employment and how it changed during the adjustment period 1984 to 1987 they find that while aggregate poverty decreased during the period the gains to the poor were quite uneven across regions and sectors gains to the rural sector in key regions were quantitatively important to indonesia s success in alleviating poverty they found most poverty exists and most gains in alleviating poverty were made in the rural farming sector these gains were associated with crop diversification and continued growth in off farm employment the government s adjustment program favored rural areas and were crucial to indonesia s evident success at maintaining momentum in alleviating poverty however one should not underrate the favorable conditions in indonesia when adjustment started

nonparametric bounds on treatment effects assume that each member of a population is characterized by values for the variables ya yb z x here x is a vector describing a person and z is a binary variable indicating which of two treatments this person receives the treatments are labelled a and b the variables ya and yb are scalar measures of the outcomes of the two treatments for example a cancer patient might be treated by a drug therapy or b surgery the relevant outcome y might be life span following treatment an unemployed worker might be given a vocational training or b job search assistance here the relevant outcome might be labor force status following treatment assume that a random sample is drawn and that one observes the realizations of z x and of the outcome under the treatment received thus ya is observed if treatment a is received but is a latent variable if treatment b is received similarly yb is either observed or latent suppose that one wants to learn the difference in expected outcome if all persons with attributes x were assigned to treatment a or b this treatment effect is

rethinking the effects of microcredit on household welfare in cambodia abstractthis article analyses the effects of microcredit on household welfare in terms of household expenditure per capita in cambodia with data from the cambodia socio economic survey carried out in 2014 the analysis describes the effects via formal and informal lending sectors accounting for endogenous selection bias arising from unobserved factors and for structural differences between borrowers and non borrowers in terms of expenditure functions the findings suggest that microcredit in both sectors reduces household expenditure

new evidence on excess sensitivity of household consumption the monthly salaries and allowances of korean government employees are known in advance but vary greatly throughout the year using a korean monthly panel data set the present study examines how nondurable consumption expenditures in households headed by government employees respond to predictable income changes the study finds a moderate excess sensitivity in consumption that can be attributed to about 9 of the households further analysis shows that these 9 of the households have lower committed expenditures and are likely inattentive consumers

asymmetric labour force participation decisions this article finds compelling evidence of asymmetric labour force participation decisions across demographic groups in response to changes in labour market conditions this behaviour is consistent with predictions from the standard labour leisure choice model and suggests that asymmetry in individual behaviour plays some role in the observed asymmetry of the aggregate unemployment rate it is estimated that the weighted average difference in response to a one percentage point change in unemployment rates is sizeable when compared to the average monthly change in the aggregate labour force

agricultural growth and poverty in an archetypical middle income country chile 1987 2003 is a reduced share of agriculture in the economy an obstacle for the agricultural sector to play an important role in poverty alleviation what is the key channel if any by which agriculture is benefiting the poor in chile that would be worthwhile to promote in other countries by answering these questions we expand the literature on poverty and composition of growth by proposing a methodology that allows to disentangle the mechanisms by which agricultural growth can be poverty reducing we find that in chile agriculture plays a large role in reducing poverty and most of this effect is channeled through the labor market

beyond agriculture versus non agriculture decomposing sectoral growth poverty linkages in five african countries summary africa s development debate is often cast as agriculture versus non agriculture with agriculture s proponents arguing that agricultural growth is more effective at reducing poverty this dual economy perspective overlooks the heterogeneity within and synergies between these two broad sectors recent studies decompose agriculture into subsectors and find that agricultural growth led by smallholder farmers is even more effective at reducing poverty than larger scale estate farms in contrast few studies estimate subsectoral growth poverty linkages for non agriculture yet we strongly expect for example that growth led by informal traders or foreign owned mining companies will have quite different implications for poverty reduction different perspectives on what constitutes non agriculture might therefore explain divergent views on its relative importance for poverty reduction to address this gap in our understanding we estimate sectoral poverty growth elasticities using economy wide models for five african countries while our estimated elasticities are higher for agriculture than for non agriculture as a whole the extent to which this is true varies considerably across nonagricultural subsectors and across countries we find that the poverty growth elasticities for trade and transport services and manufacturing especially agro processing are often close to and sometimes exceed agriculture s this means that growth led by these nonagricultural subsectors might be as effective as agriculture at reaching the poor this confirms the need for a more nuanced treatment of non agriculture in africa s policy debate and may explain conflicting perspectives on agriculture s role vis a vis non agriculture