nonstationarity in job search theory generally structural job search models are taken to be stationary in this paper models are examined in which every exogenous variable can cause nonstationarity for instance because its value is dependent on unemployment duration a general differential equation that describes the evolution of the reservation wage over time is derived as an empirical illustration a nonstationary structural model is estimated that focuses on the consequences of a downward shift in the level of benefits it appears that the elasticity of duration with respect to the level of benefits after the shift is much larger than the elasticity with respect to the level before the shift this paper examines the movement of a job seeking individual s reservation wage over time in a general nonstationary job search model also results concerning comparative dynamics of the reservation wage and the distribution of the duration of unemployment are derived as an empirical illustration a nonstationary structural model is estimated the nonstationarity originates from the decrease in the level of benefits when unemployment duration equals two years from the results some detailed policy recommendations can be deduced as one is able to distinguish the effect of a change in the level of benefits in the first two years of unemployment from the effect of a change in the level after that period recently the use of job search models for the analysis of unemployment duration has become widespread the reduced form approach in empirical studies see e g lancaster 1979 in which only the hazard of the duration distribution is estimated is gradually being replaced by a more structural approach the latter way of modelling is characterized by the explicit use in empirical analysis of the reservation wage equation as stated by the theory e g yoon 1981 lancaster and chesher 1983 lynch 1983 narendranathan and nickell 1985 and van den berg 1988 use the complete theoretical framework of job search theory to make inferences about search behaviour however the structural models used in these studies are stationary this implies that variables like unemployment benefits or the rate of arrival of job offers are assumed to be constant over the spell of unemployment which is often at variance with reality what is more various reduced form empirical studies indicate a significant durationdependence of the re employment probability which is generally interpreted as evidence in favour of the presence of nonstationarity see e g blau and robins 1986 kooreman and ridder 1983 lancaster 1979 and narendranathan nickell and stern 1985 consequently there is a need to model reservation wage movements over time based on a nonstationary theoretical framework

estimating a market equilibrium search model from panel data on individuals from albrecht and axell 1984 and is based on workers who are homogeneous in terms of market productivity and heterogeneous in terms of nonmarket productivity and on firms which are heterogeneous in terms of productive efficiency the equilibrium model is contrasted in terms of its fit to the data with an unrestricted version of the model which is based on a mixture of negative binomial distributions the equilibrium model fails to conform to the data in exactly the dimension of its major focus namely it implies that measurement error accounts for almost all of the dispersion in observed wages the equilibrium model also does not do well in fitting the unemployment duration distribution compared to the unrestricted model the problem is that the duration distribution itself does not support the existence of significant heterogeneity as evidenced by the estimates of the unrestricted model the paper also illustrates the use of such models for policy analysis by simulating the welfare effects of a minimum wage

patent quality and research productivity measuring innovation with multiple indicators we analyse the determinants of the decline in research productivity using panel data on manufacturing firms in the us for the period 1980 93 we focus on three factors the level of demand the quality of patents and technological exhaustion we develop an index of patent quality using detailed patent information and show that using multiple indicators substantially reduces the measured variance in quality research productivity at the firm level is inversely related to patent quality and the level of demand as predicted by theory and patent quality is positively associated with the stock market value of firms

are unemployment and out of the labor force behaviorally distinct labor force states this paper tests the hypothesis that the classifications unemployed and out of the labor force are behaviorally meaningless distinctions this hypothesis is rejected distinct behavioral equations govern transitions from out of the labor force to employment and from unemployment to employment the evidence reported in this paper is broadly consistent with versions of search theory in which unemployment is a state that facilitates the job search process in an appendix we demonstrate that log concavity of the wage offer distribution implies that the exit rate from unemployment is an increasing function of the rate of arrival of job offers

an empirical equilibrium job search model with search on the job and heterogeneous workers and firms in this article we present and estimate a synthesis of previous equilibrium search models allowing for continuous distributions of workers opportunity costs of employment as well as firms productivities the model allows for on the job search and we assume that job offer arrival rates for workers are independent of their labor market state we derive the theoretical implications of these assumptions we provide simulations and we develop a semiparametric estimation procedure that we apply to a dataset of individual labor market histories

an equilibrium model of search unemployment this paper develops a simple general equilibrium model with sequential search in which a nondegenerate wage offer distribution is endogenously determined we use this model to analyze the comparati

inflation and the dispersion of real wages the eects of inflation on real wage dispersion and welfare are studied in a cash in advance economy with a walrasian goods market but a labor market with search friction in which firms enjoy monopsony power in the labor market firms post wages and both the employed and the unemployed workers search among the posted wages in equilibrium a higher inflation rate reduces the dispersion in real wages this result is consistent with both the observed trends in wage dispersion and the inflation rate witnessed in the 1980 s and the 1990 s in the u s and the empirical literature linking reduced inflation to greater wage dispersion while higher inflation always lowers consumption output and employment the optimal inflation rate exceeds the friedman rule

equilibrium search with continuous productivity dispersion theory and nonparametric estimation in this article we develop an equilibrium search model with a continuous distribution of firm productivity types within a given labor market we characterize equilibrium derive expressions for the endogenous equilibrium wage distributions and characterize the set of wage distributions that can be generated by the model we develop a structural nonparametric estimation method for the productivity distribution we estimate the model using french longitudinal survey data on labor supply and we compare the results with those from a french panel data set of firms the results are informative on the degree to which firms exploit search frictions

a structural dynamic analysis of job turnover and the costs associated with moving to another job this paper provides an empirical analysis of the labor market behavior of employed individuals using a structural on the job search model the costs associated with moving to another job are allowed to be nonzero and may depend on the wage level it is shown that under certain conditions the optimal strategy has the reservation wage property the model is estimated using data on job durations and subjective responses concerning the search strategy the results reveal some strong sources of inflexibility of the labor market copyright 1992 by royal economic society

patents learning by doing and market structure in the chemical processing industries for a sample of 24 chemical products count data models are used to evaluate firms propensity to patent and the link between patented process innovations and output prices the results show that process patenting was largely an outgrowth of learning by doing propensity to patent increased with firm size but decreased with market concentration reductions in output prices were strongly linked to learning by doing and more weakly to the rate of patenting producer firms appear to have been more successful than non producers in appropriating the value of patented process innovations

international trends in technological progress evidence from patent citations 1980 2011 we analyse cross country trends in several aspects of technological progress during 1980 2011 by examining the us patent citations data our estimation results on patent quality and citation lags relative to the us reveal the following the emerging asian economies of korea taiwan and china have achieved substantial catch up in the case of korea and taiwan progress has been made in both patent quality and citation lags china has achieved improvement in patent quality but not in citation lag in contrast advanced economies of europe and japan have displayed steady decline in patent quality while the us has strengthened its position

benefit duration unemployment duration and job match quality a regression discontinuity approach summary we use a sharp discontinuity in the maximum duration of benefit entitlement to identify the effect of extended benefit duration on unemployment duration and post unemployment outcomes employment stability and re employment wages we address dynamic selection which may arise even under an initially random assignment to treatment estimating a bivariate discrete time hazard model jointly with a wage equation and correlated unobservables owing to the non stationarity of job search behavior we find heterogeneous effects of extended benefit duration on the re employment hazard and on job match quality our results suggest that the unemployed who find a job close to and after benefit exhaustion experience less stable employment patterns and receive lower re employment wages compared to their counterparts who receive extended benefits and exit unemployment in the same period these results are found to be significant for men but not for women copyright 2012 john wiley sons ltd

measuring the equilibrium effects of unemployment benefits dispersion we analyze the impact of unemployment benefits and minimum wagesusing an equilibrium search model which allows for dispersion ofbenefits and productivity levels job to job transitions andstructural and frictional unemployment the estimation method usesreadily available aggregate data on marginal distributions ofunemployment durations as well as wages and benefit levels different causes of structural and frictional unemployment areinvestigated we investigate the efficiency of the imposition of asingle benefit level for all household types and the introductionof an earned income tax credit

in work benefits in the united states the earned income tax credit the earned income tax credit eitc is or soon will be the largest cash or nearcash benefit provided to low income households in the united states the eitc is a credit on the federal income tax available to working poor families with children in i994 the credit equals 26 3 of earned income wages salaries self employment income and farm income for taxpayers with one child up to an earned income of 7 750 hence the maximum benefit is 2 038 for families with one child because benefits increase with earned income up to a certain point the eitc seems to encourage work and therefore is a popular antipoverty programme taxpayers with one child and incomes above 7 750 but below i i ooo receive the maximum benefit taxpayers with one child whose incomes exceed i i ooo are in the phase out range of the credit their 2 038 credit is reduced by i5 98 cents for every dollar of income earned over and above i i ooo taxpayers with two or more children are entitled to a slightly larger credit 2 528 or 30o0 0 of 8 425 which is phased out at a i 7p68 0 rate a small credit of at most 306 was available to childless taxpayers betnween the ages of 25 and 64 for the first time in i 994 unlike most credits and deductions in the federal individual income tax system the eitc is refundable that is if the amount of the credit exceeds what the taxpayer owes he or she receives a payment from the us treasury for the difference the eitc was adopted in i975 and was originally promoted as a way to relieve the burden of the social security payroll tax on low wage working parents 2 the original eitc equaled io 0 of earnings up to a maximum credit of 400 for taxpayers with children and was phased out at a rate of io cents per dollar of earnings or adjusted gross income whichever was higher for incomes between 4 ooo and 8 ooo the eitc has been increased many times since i975 though the largest changes occurred in i990 and i993 in i996 when the i993 legislative changes are fully phased in the credit rate will be 40 0 of earnings for families with two or more children and 34 0 for families

a great wall of patents what is behind china s recent patent explosion abstract china s patent surge documented in this paper is seemingly paradoxical given the country s weak record of protecting intellectual property rights using a firm level data set that spans the population of china s large and medium size industrial enterprises this paper explores the factors that account for china s rising patent activity while the intensification of research and development in the chinese economy tracks with patenting activity it explains only a fraction of the patent explosion the growth of foreign direct investment in china is prompting chinese firms to file for more patent applications amendments to the patent law that favor patent holders and ownership reform that has clarified the assignment of property rights also emerge as significant sources of china s patent boom these results are robust to alternative estimation strategies that account for over dispersion in the patent counts data and firm heterogeneity

unemployment duration and the restart effect some experimental evidence in this paper we analyse the effect of ihe restart programme in the united kingdom this programme consisis of an interview of tbe long term unemployed to counsel them on effective job search failure to attend the interview carries the threat of the cessation of unemployment benefits the results using experimental data indicate that the programme has a significant effect of reducing unemployment duration estimation of an independent competing risks model distinguishing between exits from unemployment to a job a training placement or to signing off unemployment benefit shows that the channels through which restart works differs according to exit type

new evidence on whether unemployment and out of the labor force are distinct states this paper focuses on the question of whether people who are out of the labor force olf should be included in unemployment measures if people who are olf can obtain jobs as often as the people who are unemployed then there is no real distinction between the two states of nonemployment surprisingly there has been very little effort surrounding this issue in the past clark and summers 1982 conclude that for teenagers unemployment and olf are not distinct states while flinn and heckman 1982a find the opposite for white male high school graduates the methodology adopted in this paper enables one to use incomplete transition data on unemployment and olf and to obtain estimates of the full transition matrix between three labor force states that are not possible with standard methods new evidence for high school graduates is presented by gender and it is found that while for young women the two states are distinct for young men they are not

the patent paradox revisited an empirical study of patenting in the u s semiconductor industry 1979 1995 we examine the patenting behavior of firms in an industry characterized by rapid technological change and cumulative innovation recent survey evidence suggests that semiconductor firms do not rely heavily on patents to appropriate returns to r d yet the propensity of semiconductor firms to patent has risen dramatically since the mid1980s we explore this apparent paradox by conducting interviews with industry representatives and analyzing the patenting behavior of 95 u s semiconductor firms during 1979 1995 the results suggest that the 1980s strengthening of u s patent rights spawned patent portfolio races among capital intensive firms but it also facilitated entry by specialized design firms

optimal unemployment insurance this paper considers the design of an optimal unemployment insurance system the problem is modeled as a repeated principalagent problem involving a risk averse agent the unemployed worker and a risk neutral principal which cannot monitor the agent s search effort the optimal long term contract subject to the associated incentive constraints is characterized this contract involves a replacement ratio that decreases throughout the unemployment spell and a wage tax after reemployment that under some mild regularity conditions increases with the lenght of the unemployment spell some numerical results are presented that suggest that the gains from switching to this optimal unemployment insurance scheme could be quite large the performance of this optimal contract is also compared to alternative liquidity provision mechanisms

structural and frictional unemployment in an equilibrium search model with heterogeneous agents we specify and estimate an equilibrium search model with between market heterogeneity in the productivity levels the model allows for two types of unemployment unemployment due to search frictions and unemployment due to wage floors wage floors may exist because of large unemployment benefits or a binding mandatory minimum wage using data on labour market histories for a sample of dutch workers we decompose the total unemployment rate in a structural and frictional unemployment rate we also discuss the effect of changes in the minimum wage

a penny for your quotes patent citations and the value of innovations the use ofpatents in economic research has been seriously hindered by the fact that patents vary enormously in their importance or value and hence simple patent counts cannot be informative about innovative output the purpose of this article is to put forward patent counts weighted by citations as indicators of the value of innovations thereby overcoming the limitations of simple counts the empirical analysis of a particular innovation computed tomography scanners indeed shows a close association between citation based patent indices and independent measures of the social value of innovations in that field moreover the weighting scheme appears to be nonlinear increasing in the number of citations implying that the informational content of citations rises at the margin as in previous studies simple patent counts are found to be highly correlated with contemporaneous rd however here the association is within afield over time rather than cross sectional

the measurement of unemployment an empirical approach although the unemployment rate is one of the most widely cited and closely monitored economic statistics the definition and measurement of unemployment remain controversial an important issue is whether non employed persons who display a marginal attachment to the labor force for example those who are available for and desire work but are not searching for work should be classified as unemployed or non participants although this issue has been extensively debated it has never been tested empirically this paper carries out empirical tests of this and related hypotheses using a unique longitudinal data set from canada we find within the marginally attached a waiting group whose behavior indicates that they would be more appropriately classified as unemployed rather than out of the labor force the remainder of the marginally attached exhibit behavior between that of the unemployed and the balance of non participants suggesting that the desire for work among non searchers conveys substantial information about labor force attachment and future employment status our methods also apply to heterogeneity within the unemployed and we investigate behavioral variation linked to differences in job search methods and reasons for entry into unemployment although those using passive job search do exhibit behavior somewhat distinct from active searchers our results reject the practice of classifying passive job searchers as out of the labor force overall our results indicate that the non employed are very heterogeneous so that any single division into unemployment and out of the labor force is unlikely to fully capture the variety of degrees of labor force attachment this abstract was borrowed from another version of this item

an empirical equilibrium search model of the labor market in structural empirical models of labor market search the distribution of wage offers is usually assumed to be exogenous however because in setting their wages profit maximizing firms should consider the reservation wages of job seekers the wage offer distribution is essentially endogenous we investigate whether a proposed equilibrium search model in which the wage offer distribution is endogenous is able to describe observed labor market histories we find that the distributions of job and unemployment spells are consistent with the data and that the qualitative predictions of the model for the wages set by employers are confirmed by wage regressions the model is estimated using panel data on unemployed and employed individuals we distinguish between separate segments of the labor market and we show that productivity heterogeneity is important to obtain an acceptable fit to the data the results are used to estimate the degree of monopsony power of firms further the effects of changes in the mandatory minimum wage are examined

a unit root model for trending time series energy variables in this paper we propose a garch based unit root test that is flexible enough to account for a trending variables b two endogenous structural breaks and c heteroskedastic data series our proposed model is applied to a range of time series trending and heteroskedastic energy variables our two main findings are first the proposed trend based garch unit root model outperforms a garch model without trend and second allowing for a time trend and two endogenous structural breaks are important in practice for doing so allows us to reject the unit root null hypothesis

wage differentials employer size and unemployment the unique equilibrium solution to a game in which a continuum of individual employers choose permanent wage offers and a continuum of workers search by sequentially sampling from the set of offers is characterized wage dispersion is a robust outcome provided that workers search while employed as well as when unemployed the unique nondegenerate equilibrium distribution of wage offers is constructed for three cases 1 identical workers and employers 2 identical employers and an atomless distribution of worker supply prices and 3 identical workers and an atomless distribution of job productivities copyright 1998 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

wages and the value of nonemployment nonemployment is often posited as a worker s outside option in wage setting models such as bargaining and wage posting the value of nonemployment is therefore a key determinant of wages we measure the wage effect of changes in the value of nonemployment among initially employed workers our quasi experimental variation in the value of nonemployment arises from four large reforms of unemployment insurance ui benefit levels in austria we document that wages are insensitive to ui benefit changes point estimates imply a wage response of less than 0 01 per 1 00 ui benefit increase and we can reject sensitivities larger than 0 03 the insensitivity holds even among workers with low wages and high predicted unemployment duration and among job switchers and recently unemployed workers the insensitivity of wages to the nonemployment value presents a puzzle to the widely used nash bargaining model which predicts a sensitivity of 0 24 0 48 our evidence supports wage setting models that insulate wages from the value of nonemployment