the macrodynamics of sorting between workers and firms we develop an equilibrium model of on the job search with ex ante heterogeneous workers and firms aggregate uncertainty and vacancy creation the model produces rich dynamics in which the distributions of unemployed workers vacancies and worker firm matches evolve stochastically over time we prove that the surplus function which fully characterises the match value and the mobility decision of workers does not depend on these distributions we estimate the model on us labour market data from 1951 2007 and predict the fit for 2008 12 we use the model to measure the cyclicality of mismatch between workers and jobs

do employers use unemployment as a sorting criterion when hiring evidence from a field experiment the stigma associated with long term unemployment spells could create large inefficiencies in labor markets while the existing literature points toward large stigma effects it has proven difficult to estimate causal relationships using data from a field experiment we find that long term unemployment spells in the past do not matter for employers hiring decisions suggesting that subsequent work experience eliminates this negative signal nor do employers treat contemporary short term unemployment spells differently suggesting that they understand that worker firm matching takes time however employers attach a negative value to contemporary unemployment spells lasting at least nine months providing evidence of stigma effects

costs and benefits to taxpayers consumers and producers from u s ethanol policies the u s ethanol industry is lobbying hard for an extension of existing ethanol import tariffs and blenders tax credits before they expire at the end of 2010 the purpose of this study is to examine the likely consequences on the u s ethanol industry corn producers taxpayers fuel blenders and fuel consumers if current policy is not extended impacts of different ethanol policies in both 2011 and 2014 were estimated estimates were obtained by developing a new stochastic model that calculates market clearing prices for u s ethanol brazilian ethanol and u s corn the model is stochastic because market clearing prices are calculated for 5 000 random draws of corn yields and wholesale gasoline prices key assumptions in this study are that the strong growth in flex fuel vehicles in brazil continues intermediate ethanol blends with few restrictions are implemented in u s markets in 2014 u s ethanol production capacity reaches 15 billion gallons in 2014 and brazilian ethanol production increases by at least 45 by 2014 projected strong demand for ethanol in brazil combined with a largely saturated u s ethanol market means that elimination of ethanol import tariffs would have almost no impact on u s corn and ethanol markets in 2011 elimination of the tax credit would impact markets modestly with ethanol production declining by an average of about 700 million gallons this reduction in ethanol production would cause corn prices to drop by an average of 23 cents per bushel ethanol prices would drop by 12 cents per gallon elimination of the tax credit would shift the burden of meeting mandates from taxpayers to blenders and consumers taxpayers would save more than 6 billion through elimination of the tax credit or almost 7 00 per gallon of ethanol produced in excess of mandated amounts the impacts of a change in u s ethanol policy in 2014 are larger than 2011 impacts because brazil has a chance to respond by ramping up its ability to export in response to trade liberalization but because of strong domestic demand growth in brazil and limits on how fast brazilian ethanol production can increase the impacts of a change in policy are still modest as long as the mandate is maintained u s ethanol production drops by no more than 500 million gallons corn prices drop by no more than 16 cents per bushel and ethanol prices drop by no more than 35 cents per gallon if the impact of intermediate blends is not as strong as assumed in this study then there will be less incentive for brazil to export ethanol and the impacts of tariff elimination would be even more modest

employer search training and vacancy duration we develop a model of optimal employer search strategy when information about match quality is endogenous the model is tested using four data sets two of which have not previously been used as theory predicts we find that when filling positions requiring more training employers search more intensively and extensively employers also search more extensively when hiring workers with more education and with prior experience these findings provide strong evidence of systematic variation in search strategies based on the characteristics of the positions and job applicants factors that influence employer search also affect the duration of a vacancy

job search stigma effect and escape rate from unemployment this article formulates job search models incorporating certain types of the stigma effect of unemployment it is assumed that the probability of getting a job offer given the unemployment individual contacts the firm is influenced by the duration of unemployment and is justified in a signaling context the optimal search is analyzed for one sector as well as across several independent labor market segments it is shown that there are reasonably general conditions on the search environments for which both the individual reservation wage and escape rate are negative duration dependent a fact observed in empirical studies

cashier or consultant entry labor market conditions field of study and career success we measure impacts of entry conditions on labor market outcomes for the us college graduating classes of 1974 2011 a large recession reduces initial earnings by 10 through full time work and wag

the effect of unemployment benefits and nonemployment durations on wages abstract we estimate that unemployment insurance ui extensions reduce reemployment wages using sharp age discontinuities in ui eligibility in germany we show this effect combines two key policy parameters the effect of ui on reservation wages and the effect of nonemployment durations on wage offers our framework implies if ui extensions do not affect wages conditional on duration then reservation wages do not bind we derive resulting instrumental variable estimates for the effect of nonemployment durations on wage offers and bounds for reservation wage effects the effect of ui on wages we find arises mainly from substantial negative nonemployment duration effects jel j31 j64 j65

will affirmative action policies eliminate negative stereotypes a key question concerning affirmative action is whether the labor market gains it brings to minorities can continue without it becoming a permanent fixture in the labor market the authors argue that this depends on how the policy affects employers beliefs about the productivity of minority workers they study the joint determination of employer beliefs and worker productivity in a model of statistical discrimination in job assignments the authors prove that even when identifiable groups are equally endowed ex ante affirmative action can bring about a situation in which employers correctly perceive the groups to be unequally productive ex post copyright 1993 by american economic association

on the effects of ranking by unemployment duration abstract we propose a theory based on the firm s hiring behavior that rationalizes the observed significant decline of callback rates for an interview and exit rates from unemployment and the mild decline of reemployment wages over unemployment duration we build a directed search model with symmetric incomplete information on worker types and non sequential search by firms sorting due to firms testing of applicants in the past makes expected productivity fall with duration which induces firms to rank applicants by duration in equilibrium callback and exit rates both fall with unemployment duration in our numerical exercise using u s data we show that our model can replicate quite well the observed falling patterns with the firm s ranking decision accounting for a sizable part

land use intensification potential in slash and burn farming through improvements in technical efficiency abstract much attention is being paid to find alternative land use options in slash and burn sab farming or forest fallow based shifting cultivation systems the conservation objective is often twofold that is to discourage farmers from expanding into the forest frontier and to reduce the ecological damage from burning plots options include the total abandonment of forest plots the adoption of productivity increasing green revolution type technologies and the application of modern evergreen agroforestry knowledge this paper evaluates another alternative the intensification of land use by improving technical efficiency in farming this involves the reduction of land clearing while at the same time maintaining crop output levels and the local and traditional low input technology the potential for such land use intensification is empirically assessed with ecological and socioeconomic household data from yucatan mexico the methodology is based on both parametric and nonparametric output and input distance functions in addition the sources of inefficiency are addressed the results of the analysis suggest that on and off farm labour diversification can play a key role to help shifting cultivating households to improve their technical efficiency in farming and thus to help to intensify land use furthermore while the empirical results point towards the positive effect of soil fertility mainly determined by the length of forest fallows on crop output levels farmers appear to overcome the ecological constraint of farming in less fertile soils by being more technically efficient

a matching model with endogenous skill requirements we consider a labor market in which workers differ in their abilities and jobs differ in their skill requirements the distribution of worker abilities is exogenous but we model the choice of skill requirements by firms high skill jobs produce more output than low skill jobs but high skill jobs require high skill workers and thus are more difficult to fill we use a matching model together with a nash bargaining approach to wage setting to determine the equilibrium mix of job types along with the equilibrium relationship between worker and job characteristics wages and unemployment

statistical discrimination and duration dependence in the job finding rate this article models a frictional labour market where employers endogenously discriminate against the long term unemployed the estimated model replicates recent experimental evidence which documents that interview invitations for observationally equivalent workers fall sharply as unemployment duration progresses we use the model to quantitatively assess the consequences of such employer behaviour for job finding rates and long term unemployment and find only modest effects given the large decline in callbacks interviews lost to duration impact individual job finding rates solely if they would have led to jobs we show that such instances are rare when firms discriminate in anticipation of an ultimately unsuccessful application discrimination in callbacks is thus largely a response to dynamic selection with limited consequences for structural duration dependence and long term unemployment

information externalities in the labour market and the duration of unemployment a matching model is analysed in which firms imperfectly test workers prior to hiring them if some firms hire only workers who pass the test there is an informational externality unemployment duration is a signal of productivity in equilibrium if it is profitable for a firm to test it is also profitable for it to condition its hiring decision on duration hiring those whose duration is less than a critical value this testing equilibrium is inefficient with too much testing and too low a critical duration value sensitivity analysis of the latter suggests explanations for the dependence of re employment probabilities on duration and the instability of the u v curve

extensive search intensive search and hiring costs new evidence on employer hiring activity this paper presents recent evidence on employer search to fill a position a 1982 employer survey sponsored by the national institute of education and the national center for research in vocational education provides the basis for analyzing employer search and hiring costs the paper examines the effects of such factors as employer size dismissal costs unionization on the job training adjustment costs capital and labor market conditions on intensive employer search extensive employer search and hiring costs intensive employer search is measured by the average number of hours the employer spends recruiting screening and interviewing per applicant extensive search is measured by the number of applicants seen per applicant interviewed and the number interviewed per employment

heterogeneity and unemployment dynamics many previous articles have studied the contribution of inflows and outflows to the cyclical variation in unemployment but ignored the critical role of unobserved heterogeneity across workers thi

duration dependence and labor market conditions evidence from a field experiment this article studies the role of employer behavior in generating negative duration dependence the adverse effect of a longer unemployment spell by sending fictitious resumes to real job postings in 100 u s cities our results indicate that the likelihood of receiving a callback for an interview significantly decreases with the length of a worker s unemployment spell with the majority of this decline occurring during the first eight months we explore how this effect varies with local labor market conditions and find that duration de pendence is stronger when the local labor market is tighter this result is consistent with the prediction of a broad class of screening models in which employers use the unemployment spell length as a signal of unobserved productivity and recognize that this signal is less informative in weak labor markets jel code j64

the assignment of workers to jobs in an economy with coordination frictions this paper studies the assignment of heterogeneous workers to heterogeneous jobs owing to the anonymity of a large labor market workers use mixed strategies when applying for jobs this randomness generates coordination frictions two workers may apply for a particular job whereas an identical job gets no applications the model generates assortative matching with a positive but imperfect correlation between matched workers and firms types it predicts that a worker s wage is increasing in her job s productivity and a firm s profit is increasing in its employees productivity the model also yields a version of the welfare theorems

opportunity for profitable investments in cellulosic biofuels research efforts to allow large scale conversion of cellulose into biofuels are being undertaken in the us and eu these efforts are designed to increase logistic and conversion efficiencies enhancing the economic competitiveness of cellulosic biofuels however not enough attention has been paid to the future market conditions for cellulosic biofuels which will determine whether the necessary private investment will be available to allow a cellulosic biofuels industry to emerge we examine the future market for cellulosic biofuels differentiating between cellulosic ethanol and drop in cellulosic biofuels that can be transported with petroleum fuels and have equivalent energy values we show that emergence of a cellulosic ethanol industry is unlikely without costly government subsidies in part because of strong competition from conventional ethanol and limits on ethanol blending if production costs of drop in cellulosic biofuels fall enough to become competitive then their expansion will not necessarily cause feedstock prices to rise as long as local supplies of feedstocks that have no or low valued alternative uses exist then expansion will not cause prices to rise significantly if cellulosic feedstocks come from dedicated biomass crops then the supply curves will have a steeper slope because of competition for land

nonemployment stigma as rational herding a field experiment abstract long spells of unemployment are known to reduce the likelihood of re employment but it is difficult to discern the reasons for this observation using an experimental method that controls for search intensity and possible discouragement of job applicants i document that job market opportunities for the nonemployed diminish rapidly over time in this experiment duration dependence is solely due to firm perceptions why do firms view long spells of nonemployment as negative signals rational herding is one important factor managers believe that unemployed applicants were previously interviewed and if the applicants were productive they would have been hired

ranking unemployment duration and wages it explores the implication of one central assumption when firms receive multiple acceptable applications they hire the worker who has been unemployed for the least amount of time this assumption ranking is contrasted with the assumption of random hiring no ranking by embodying this assumption in a model of the labour market with job creation destruction and matching the joint behaviour of unemployment the distribution of unemployment durations and wages are characterized the implication that the re employment prospects of employed workers were they to become unemployed are better than those of the currently unemployed appears to have been an important feature of european unemployment experience in the 1980 s this paper examines the effects of the composition of unemployment on wage determination it explores one central assumption when firms receive multiple acceptable applications they hire the worker who has been unemployed for the least amount of time we refer to this assumption as ranking and contrast it throughout to the assumption of random hiring or no ranking by embodying this assumption in a model of the labour market with job creation destruction and matching we characterize the joint behaviour of unemployment the distribution of unemployment durations and wages ranking has a number of important implications first in addition to the obvious result that the exit rate from unemployment is a decreasing function of duration we show that the effect of duration is stronger the higher the rate of unemployment second with the wage depending on the distributions of prospective unemployment durations the presence of long term unemployed per se has little effect on wages third looking at the relation between the wage and the aggregate level of unemployment and comparing ranking to the case of no ranking the wage moves less with the level of unemployment but more with the change in unemployment put simply ranking and no ranking models show exactly the same aggregate unemployment slightly different long run responses of wages to unemployment and sharply different wage dynamics the paper is organized as follows section i characterizes the matching process and derives a matching function based on an urn ball process with vacancies as urns and applications by unemployed workers as balls thus the distribution of applications per vacancy depends on aggregate unemployment and vacancies vacancies with at least one acceptable application are filled when a vacancy receives more than one acceptable application firms use a rule to choose among applicants thus the rule determines who is hired but does not affect the number of hires section ii uses this matching function in a model of the labour market with continual job creation and destruction and characterizes the equilibrium values of unemployment vacancies and hires

income variance dynamics and heterogeneity recent theoretical work has shown the importance of measuring microeconomic uncertainty for models of both general and partial equilibrium under imperfect insurance in this paper the assumption of i i d income innovations used in previous empirical studies is removed and the focus of the analysis is placed on models for the conditional variance of income shocks which is related to the measure of risk emphasized by the theory we first discriminate amongst various models of earnings determination that separate income shocks into idiosyncratic transitory and permanent components we allow for education and time specific differences in the stochastic process for earnings and for measurement error the conditional variance of the income shocks is modelled as a parsimonious arch process with both observable and unobserved heterogeneity the empirical analysis is conducted on data drawn from the 1967 1992 panel study of income dynamics we find strong evidence of sizeable arch effects as well as evidence of unobserved heterogeneity in the variances

determinants of callbacks to job applications an audit study abstract we summarize findings from an audit study investigating how unemployment duration age and holding a low level interim job affect the likelihood that experienced college educated females applying for administrative support jobs receive a callback from potential employers the results show no relationship between callback rates and unemployment duration in contrast workers age 50 and older and workers with an interim job are significantly less likely to receive callbacks we also summarize disparate findings in the growing literature of resume based audit studies of career histories and discuss avenues in which the literature could achieve results that are more comparable and externally valid