money and capital abstract the effects of money anticipated inflation on capital formation is a classic issue in macroeconomics previous papers adopt reduced form approaches putting money in the utility function or imposing cash in advance but using otherwise frictionless models we follow instead a literature that tries to be explicit about the frictions making money essential this introduces new elements including a two sector structure with centralized and decentralized markets stochastic trading opportunities and bargaining these elements matter quantitatively and numerical results differ from findings in the reduced form literature the analysis also reduces a gap between microfounded monetary economics and mainstream macro

equilibrium in the labor market with search frictions christopher a pissarides delivered his prize lecture on 8 december 2010 at aula magna stockholm university this abstract was borrowed from another version of this item

choosy search and the mismatch of talents this article proposes a multi sector matching model where workers have symmetric sector specific skills and the search market is segmented by sector workers choose the range of markets they are willing to participate in i identify a composition externality workers do not take into account the impact of their choice on sector specific mean productivity among the pools of job seekers consequently workers prospect too many market segments and there is room for public policy even when the so called hosios condition holds

estimation of scale economies underlying growth and productivity the empirical implications of data aggregation estimation of scale economies underlying growth and productivity patterns is typically based on aggregated data raising questions about the potential for aggregation biases this paper provides empirical evidence on the existence and patterns of such biases we use a cost based model to estimate short long run and internal external scale effects for u s manufacturing data at different aggregation levels our results suggest that aggregation biases in such a model are not substantive also internal scale economies seem more appropriately represented by the aggregate data whereas more disaggregated data appears preferable for estimation of external or spillover effects that occur between industries or sectors

equilibrium price dispersion with sequential search abstract the paper studies equilibrium pricing in a product market for an indivisible good where buyers search for sellers buyers search sequentially for sellers but do not meet every seller with the same probability specifically a fraction of the buyers meetings lead to one particular large seller while the remaining meetings lead to one of a continuum of small sellers in this environment the small sellers would like to set a price that makes the buyers indifferent between purchasing the good and searching for another seller the large seller would like to price the small sellers out of the market by posting a price that is low enough to induce buyers not to purchase from the small sellers these incentives give rise to a game of cat and mouse whose only equilibrium involves mixed strategies for both the large and the small sellers the fact that the small sellers play mixed strategies implies that there is price dispersion the fact that the large seller plays mixed strategies implies that prices and allocations vary over time we show that the fraction of the gains from trade accruing to the buyers is positive and nonmonotonic in the degree of market power of the large seller as long as the large seller has some positive but incomplete market power the fraction of the gains from trade accruing to the buyers depends in a natural way on the extent of search frictions

on optimal public good provision with tax evasion it is proved that for public goods with zero income effects also called ziff public goods tax evasion does not affect the optimal level of public expenditure further examples show that in general tax evasion may lead to less but also to more public expenditure

job search with bidder memories this paper revisits the no recall assumption in job search models with take it or leave it offers workers who can recall previously encountered potential employers in order to engage them in bertrand bidding have a distinct advantage over workers without such attachments firms account for this difference when hiring a worker when a worker first meets a firm the firm offers the worker a sufficient share of the match rents to avoid a bidding war in the future the pair share the gains to trade in this case the diamond paradox no longer holds

life cycle equilibrium unemployment this paper extends the job creation job destruction approach to the labor market to take into account a deterministic finite horizon as hirings and separations depend on the time over which investment costs can be recouped the life cycle setting implies age differentiated labor market flows while search by the unemployed falls with age the separation rate is rather u shaped over the life cycle worker heterogeneity in the context of undirected search implies an intergenerational externality which is not eliminated by the hosios condition we show that age specific policies are required to attain the first best allocation

competitive search equilibrium in this paper i construct an equilibrium for markets with frictions which is competitive in the sense that all agents are price takers and maximize utility subject to a set of market parameters i show that the equilibrium allocation is socially optimal i also show how the competitive search equilibrium can be achieved if employers with vacancies can advertise publicly the wages they pay

dynamic contracts with worker mobility via directed on the job search this article proposes a model with dynamic incentive contracts and on the job search in a frictional labor market the optimal long term contract exhibits an increasing wage tenure profile with increasing wages worker effort also increases with tenure these two features imply that the probabilities of both voluntary and involuntary job separation decrease with both job tenure and the duration of employment given these results workers experience differing labor market transitions between employment unemployment and across different employers and the equilibrium generates endogenous heterogeneity among ex ante homogeneous workers abstract from author

representative evidence on lying costs abstract a central assumption in economics is that people misreport their private information if this is to their material benefit several recent models depart from this assumption and posit that some people do not lie or at least do not lie maximally these models invoke many different underlying motives including intrinsic lying costs altruism efficiency concerns or conditional cooperation to provide an empirically validated microfoundation for these models it is crucial to understand the relevance of the different potential motives we measure the extent of lying costs among a representative sample of the german population by calling them at home in our setup participants have a clear monetary incentive to misreport misreporting cannot be detected reputational concerns are negligible and altruism efficiency concerns or conditional cooperation cannot play a role yet we find that aggregate reporting behavior is close to the expected truthful distribution suggesting that lying costs are large and widespread further lab experiments show that this result is not driven by the mode of communication

computers and productivity are aggregation effects important this paper examines the empirical implications of aggregation bias when measuring the productive impact of computers to isolate two specific aggregation problems relating to aggregation in variables and aggregation in relations we compare various production function estimates across a range of specifications econometric estimators and data levels the results show that both sources of bias are important especially as one moves from the sector to the economy level and when the elasticity of all types of non computer capital are incorrectly restricted to be equal in terms of computers however the estimated elasticity is surprisingly stable between industry and sector regressions and does not appear to be biased by the incorporation of a restrictive measure of non computer capital the data consistently show that computers have a large impact on output

information technology and its impact on productivity firm level evidence from government and private data sources 1977 1993 robert solow s quip that we see computers everywhere but in the productivity statistics has prompted a large and growing literature examining the information productivity paradox some aggregate and industry level studies have failed to detect a positive contribution to productivity growth from investments in computer technology more recent studies utilizing firm level data however have detected a significant contribution this paper confirms the results of these latter studies using u s firm level computer asset and financial data for nonagricultural firms during the period 1977 1993 from a variety of data sources including the u s census bureau s enterprise and auxiliary establishment surveys compustat and computer intelligence infocorp a market research firm our principal finding that computers especially personal computers do contribute positively to productivity growth suggests that the traditional information productivity paradox is largely a measurement problemn this is closely related to the more general problem of assessing service sector productivity because computers are used most intensively in the service sector and in the service functions of non service sector firms e g payroll and purchasing as zvi griliches 1994 noted these activities pose the greatest problems for output and productivity measurement moreover although we may see computers everywhere they represent only a tiny fraction of capital stock on about 2 of plant property and equipment so aggregate effects may be hard to detect oliner and sichel 1993 our data indicate that computers not only contributed to productivity growth during the period 1977 1993 but they yielded excess returns relative to other types of capital the data also suggest that computer productivity peaked around 1986 1987 3 that computers are complementary with skilled labour krueger 1993 and autor katz and krueger 1997 and that use of computers may permit reductions in inventory levels finally and perhaps most interesting the evidence

the impact of high tech capital on productivity evidence from australia i introduction the bulk of the empirical research on the relationship between high tech capital investment and productivity has been based on data for the united states given the relatively large size of the high tech capital sector in the u s economy it is likely that the united states is a special case most economies resemble australia s in being net importers of high tech capital not producing high tech capital was often cited as a weakness in these economies relative to the united states however since the end of the late 1990s tech boom there has been a reappraisal of whether the production or the use of high tech capital is most beneficial hence to shed light on this debate the main purpose of this paper is to empirically examine the relationship between high tech capital use and the multifactor productivity mfp of 10 industries in the australian market sector using annual data for 1966 2002 alternative specifications of production functions are considered and estimated alternative measures of high tech capital are included with combinations of computers software and electronics capital in the first production function high tech capital is allowed to be more or less productive than other capital to determine whether there is a relationship between high tech capital and mfp it is also possible to test whether there are excess returns to high tech capital for robustness testing purposes a second production function is specified with high tech capital as a separate input into production other potential sources of mfp growth such as public capital research and development stocks and microeconomic reform are also included in the production functions we find evidence of a positive relationship between high tech capital and mfp in the market sector there is less evidence however of excess returns to high tech capital which suggests that current investment levels are not inadequate the results by industry suggest that the benefits of investing in high tech capital are not distributed evenly across the economy with only some industries experiencing a positive relationship between high tech capital and mfp the structure of this article is as follows in section ii the theoretical contribution of high tech capital to mfp and the evidence to date is reviewed in section iii the methodology is outlined in section iv data sources and trends are described in section v the results are presented and interpreted and section vi concludes ii the impact of high tech capital on output and productivity the theory and evidence the impact of investment in high tech capital has been the subject of debate between new economy sceptics and optimists for several years it is widely accepted that mfp has increased substantially in u s high tech producing industries in which the rate of technological change has been phenomenal over the past 40 years several publications have found a quantifiable contribution by computer producing industries to u s output growth 1 however australia is not generally regarded as a producer of computers data from the organisation for economic co operation and development oecd 1998 indicate that the high tech share of australian manufacturing value added was 4 5 in 1995 compared to 15 8 in the united states therefore the substantial u s economy wide mfp improvements specifically associated with its computer producing industry are unlikely to be replicated in the australian economy over the past 30 years there has been rapid accumulation of high tech capital in many countries australia was the third most intensive user of high tech capital in the oecd in 1995 behind the united states and new zealand simon and wardrop 2002 find that this rapid accumulation of high tech capital may have substantially contributed to australia s economic growth during the 1990s this accumulation has been driven by technological change in high tech producing industries lowering the price of high tech capital

information technology and growth the rapid diffusion of information technology it is a direct consequence of the swift decline in the price of computer related equipment which has led to a vast and continuing substitution of it equipment for other forms of capital and labor this substitution generates substantial returns for the economic agents who undertake it investments and restructure their activities in order to increase the role of it there is little evidence however that substitution is accompanied by technical change as this term is used by economists while this appears highly paradoxical to technologists who think of substitution of a more it intensive mode of production for a less itintensive mode as a change in technology it is entirely consistent with the economic framework developed by robert m solow 1957 what do economists mean by technical change and how could this exclude the substitution of a more it intensive production process for one that is less it intensive substitution represents movement along a given production function while technical change corresponds to a shift in the production function substitution takes place if the introduction of computer intensive equipment produces benefits that are fully captured or internalized by the users of it and their suppliers technical change occurs only if more

estimating the stock flow matching model using micro data we estimate the stock flow matching model using micro level data from a well defined labor market using a dataset of complete labor market histories for both sides of the market we estimate hazard functions for job seekers and vacancies we find that the stock of new vacancies has a significant positive impact on the job seeker hazard over and above that of the total stock of vacancies there is an even stronger robust result for vacancy hazards thus we find evidence in favor of stock flow matching even when controlling for unobserved search heterogeneity and stratifying into submarkets defined by location and occupation

equilibrium using credit or money with indivisible goods this note studies the trade of indivisible goods using credit or money in a frictional market we show how indivisibility matters for monetary equilibrium under different assumptions about price determination bargaining generates a price and allocation that are independent of the nominal interest or inflation rate over some range this is not the case with price posting and directed search in either case we provide conditions the nominal rate cannot be too high under which stationary monetary equilibrium exists and we show it is unique or generically unique

scale effects in markets with search estimates of aggregate matching functions may miss important scale effects in frictional labour markets because of the reactions of job seekers to scale we estimate a semi structural model of search and matching on a british sample of unemployed people testing for scale effects on the probability of receiving an offer and on the distribution of wage offers we find them only in wage offers but we also find that reservation wages rise to deliver higher post unemployment wages but not faster matches so aggregate matching functions should be unaffected by scale but wage equations should be showing them

competing for order flow in otc markets we develop a model of a two sided asset market in which trades are intermediated by dealers and are bilateral dealers compete to attract order flow by posting the terms at which they execute trades which can include prices quantities and execution times and investors direct their orders toward dealers that offer the most attractive terms of trade equilibrium outcomes have the following properties first investors face a trade off between trading costs and speeds of execution second the asset market is endogenously segmented in the sense that investors with different asset valuations and different asset holdings will trade at different speeds and different costs for example under a leontief technology to match investors and dealers per unit trading costs decrease with the size of the trade in accordance with the evidence from the market for corporate bonds third dealers implicit bargaining powers are endogenous and typically vary across sub markets finally we obtain a rich set of comparative statics both analytically by studying a limiting economy where trading frictions are small and numerically for instance we find that the relationship between trading costs and dealers bargaining power can be hump shaped

inflation output and welfare this paper studies the effects of anticipated inflation on aggregate output and welfare within a search theoretic framework we allow money holders to choose the intensities with which they search for trading partners so inflation affects the frequency of trade as well as the quantity of output produced in each trade we consider the standard pricing mechanism for search models i e ex post bargaining as well as a notion of competitive pricing if prices are bargained over the equilibrium is generically inefficient and an increase in inflation reduces buyers search intensities output and welfare if prices are posted and buyers can direct their search search intensities are increasing with inflation for low inflation rates and decreasing for high inflation rates the friedman rule achieves the first best allocation and inflation always reduces welfare even though it can have a positive effect on output for low inflation rates

sorting and decentralized price competition we investigate the role of search frictions in markets with price competition and how it leads to sorting of heterogeneous agents there are two aspects of value creation the match value when two agents actually trade and the probability of trading governed by the search technology we show that positive assortative matching obtains when complementarities in the former outweigh complementarities in the latter this happens if and only if the match value function is root supermodular that is its nth root is supermodular where n reflects the elasticity of substitution of the search technology this condition is weaker than the condition required for positive assortative matching in markets with random search

competitive equilibrium and the core in club economies with anonymous crowding in club economies with anonymous crowding competitive equilibrium states of the economy are efficient and coincide with the core when there is only one private good anonymous admission prices permit consumers with different tastes to share facilities consumers might do so when their demands for facility size and crowding coincide in which case sharing is efficient thus similarity of demands is the relevant consideration for efficiently grouping consumers with different tastes

frictional wage dispersion in search models a quantitative assessment we propose a new measure of frictional wage dispersion the mean min wage ratio for a large class of search models we show that this measure is independent of the wage offer distribution but depends on statistics of labor market turnover and on preferences under plausible preference parameterizations observed magnitudes for worker flows imply that in the basic search model and in most of its extensions frictional wage dispersion is very small notable exceptions are some of the most recent models of on the job search our new measure allows us to rationalize the diverse empirical findings in the large literature estimating structural search models

robust comparative statics in large dynamic economies we consider infinite horizon economies populated by a continuum of agents subject to idiosyncratic shocks this framework contains models of saving and capital accumulation with incomplete markets in the spirit of works by bewley aiyagari and huggett models of entry exit and industry dynamics in the spirit of hopenhayn s work and dynamic models of occupational choice and search models as special cases robust and easy to apply comparative statics results are established with respect to exogenous parameters as well as various kinds of changes in the markov processes governing the law of motion of the idiosyncratic shocks

toward a theory of vacancies we attempt to further characterize the search strategies of the employer in the article we discuss how characteristics of the employer or conditions that the employer faces affect the optimal search strategies and the probability of filling a vacancy in each period semiparametric and parametric methods are used to estimate hazard rates of filling vacancies the results suggest that for the given sample of vacancies the general form of the hazard function is nonmonotonic additionally the results suggest that those employers who have advance notice of the vacancy may search longer than those employers who do not

marketplaces and matching this paper models equilibrium trading patterns when marketplaces exist and goods are differentiated when first visiting the market a buyer samples a stock of goods if fortunate the buyer matches with and purchases one of these goods and then exits the market if an initial match does not exist the buyer can now only match with the flow of new goods for sale the previous stock has been sampled and rejected in a steady state the current stock of unmatched traders on one side of the market is trying to match with the flow of new traders on the other side it is shown that this market behaviour describes matching patterns between unemployed job seekers and vacancies in uk job centres

spatial growth and industry age between 1970 and 2000 employment growth across u s counties exhibited very different patterns in manufacturing and services whereas manufacturing employment growth was negatively related to initial manufacturing employment across the entire distribution of counties service employment growth was positively related to initial service employment for intermediate sized counties this paper presents a theory to rationalize these facts local sectoral growth is driven by technological diffusion across space and depends on the age of the sector the theory correctly predicts the relation between county employment growth and initial county employment in manufacturing at the turn of the 20th century

equilibrium wage dispersion and interindustry wage differentials this paper develops a search theoretic explanation of interindustry wage differentials given coordination problems in the labor market the probability of filling a vacancy is an increasing function of the wage offered in equilibrium firms that find vacancies more costly will offer higher wages the model thus explains the persistence of interindustry wage differentials and their correlation with industry average capital labor ratio and profitability additionally the model predicts that high wage firms will receive more applications per job opening and that wages in the labor market will behave as strategic complements

the effectiveness of hiring credits this article analyses the effectiveness of hiring credits using comprehensive administrative data we show that the french hiring credit implemented during the great recession had significant positive employment effects and no effects on wages relying on the quasi experimental variation in labour cost triggered by the hiring credit we estimate a structural search and matching model simulations of counterfactual policies show that the effectiveness of the hiring credit relied to a large extent on three features it was non anticipated temporary and targeted at jobs with rigid wages we estimate that the cost per job created by permanent hiring credits either countercyclical or time invariant in an environment with flexible wages would have been much higher

targeted search with horizontal differentiation in the marriage market abstract we develop a search matching model in the marriage market with heterogeneous men a continuum of types and heterogeneous women a finite number of types the model has two distinguishing features first men and women are also horizontally differentiated second the search is targeted each type of woman constitutes a distinctive submarket and men are able to choose beforehand in which submarkets to participate but the search is random within each submarket we show that there is always a unique equilibrium in which men are endogenously segmented into different submarkets and that the equilibrium matching pattern is weakly positive assortative we then explore how the equilibrium marriage pattern changes horizontally and vertically as some exogenous shocks occur in particular we show that an internet induced increase in search efficiency would make the marriage pattern overall more assortative while an increase in the dispersion of the horizontal match fitness could make the marriage pattern overall less assortative

intertemporal labour supply with search frictions starting in the 1970 s wage inequality and the number of hours worked by employed u s prime age male workers have both increased we argue that these two facts are related we use a labour market model with on the job search where by working longer hours individuals acquire greater skills since job candidates are ranked by productivity greater skills not only increase worker s productivity in the current job but also help the worker to obtain better jobs when job offers become more dispersed wage inequality increases and workers work longer hours to obtain better jobs as a result average hours per worker in the economy increase this mechanism accounts for around two thirds of the increase in hours observed in data part of the increase is inefficient since workers obtain better jobs at the expense of other workers competing for the same jobs copyright oxford university press

a search model of rental markets who should pay the commission abstract we develop a dynamic search equilibrium model of rental markets with brokerage fees an endogenous mass of landlords and tenants is active in the search market while the mass of entering tenants is exogenous the mass of entering landlords is endogenously determined by the rate at which apartments become vacant brokerage fees paid by tenants are used as a device to screen short term and long term tenants we analyze a policy that requires fees to be paid by landlords such a policy decreases efficiency by preventing efficient screening but also increases turnover and hence efficiency in the search market we further provide empirically testable implications of our theory

bidding for money we analyze monetary exchange in a model that allows for directed search and multilateral matches we consider environments with divisible goods and indivisible money and compare the results with those in models that use random matching and bilateral bargaining two different pricing mechanisms are used ex ante price posting and ex post bidding auctions also we consider settings both with and without lotteries we find that the model generates very simple and intuitive equilibrium allocations that are similar to those with random matching and bargaining but with different comparative static and welfare properties

frictional assignment i efficiency abstract this paper examines the two sided matching problem where the agents on each side of the market are heterogeneous and the matching process is time consuming this is cast in a labor market setting where workers of different skills match with different machine qualities i characterize the efficient allocation and then show that it can be decentralized by a market mechanism the efficient assignment is not always positively assortative despite the fact that machine qualities and skills are complementary in production to decentralize the efficient allocation the market mechanism requires the firms to post wages and commit each machine quality to a particular skill implications on wage inequality are briefly examined journal of economic literature classification numbers j31 e24 j64

unemployment compensation finance and labor market rigidity abstract the systematic use of experience rating is an original feature of the u s unemployment benefits system at first glance experience rating does not appear to be a desirable choice for a lot of european labor markets which are characterized by high firing costs we provide a simple matching model of a rigid labor market that includes firing costs temporary jobs and a minimum wage in order to analyze this issue our analysis leads us to argue that experience rating is likely to reduce unemployment and improve the welfare of low skilled workers in france and more generally for low skilled workers in a typical rigid continental european labor market

optimal unemployment insurance in search equilibrium should unemployment benefits be paid indefinitely at a fixed rate or should the rate decline or increase over a worker s unemployment spell we examine these issues using an equilibrium model of search unemployment the model features worker firm bargaining over wages free entry of new jobs and endogenous search effort among the unemployed the main result is that an optimal insurance program implies a declining benefit sequence over the spell of unemployment numerical calibrations of the model suggest that there may be nontrivial welfare gains associated with switching from an optimal uniform benefit structure to an optimally differentiated system

sorting versus screening search frictions and competing mechanisms in a market where sellers compete by posting trading mechanisms we allow for a general search technology and show that its features crucially affect the equilibrium mechanism price posting prevails when meetings are rival i e when a meeting by one buyer reduces another buyer s meeting probability under price posting buyers reveal their type by sorting ex ante only if the meeting technology is sufficiently non rival price posting is not an equilibrium multiple buyer types then visit the same sellers who screen ex post through auctions

stock flow matching this paper develops and quantifies the implications of the stock flow matching model for unemployment job vacancies and worker flows workers and jobs are heterogeneous so most worker job pairs cannot profitably match leading to the coexistence of unemployed workers and job vacancies productivity shocks cause fluctuations in the number of active jobs which in turn cause fluctuations in labor market outcomes we derive exact expressions for employment and worker transition rates in a finite economy and analyze their limiting behavior in a large economy a calibrated version of the model is consistent with the co movement of labor market variables observed in u s data and can explain about one third of their volatility

environmental policy and the equilibrium rate of unemployment abstract this paper integrates environmental policy instruments with the theory of equilibrium unemployment we investigate the question of whether a low equilibrium rate of unemployment and a high quality of the environment are complementary policy goals or must be traded off it turns out that an interval exists for a tax on emissions where the two goals are indeed complementary the tax stimulates the emergence of an abatement sector which provides pollution control and vacancies for the job seekers for constrained efficiency the policy maker operates five instruments to internalize the environmental and the search externalities a tax on emissions employment subsidies and recruiting allowances for the polluting industries are sufficient to implement the first best the optimal emission tax is an increasing function of the workers bargaining strength for labor markets where workers have a strong bargaining position the optimal pollution tax may easily exceed the pigouvian tax

the long side of the market and the short end of the stick bargaining power and price formation in buyers sellers and balanced markets the determinants of bargaining power and price formation in a dynamic exchange market where new traders enter randomly over time are studied when agents on the long side of the market possess the option to wait for the arrival of future partners the terms of trade in the spot market must honor the value of this option the equilibrium terms of trade are expressed in intuitive closed form equations that highlight the distinct influences of short run spot market conditions and long run market demographics i introduction few concepts in economics are as intuitive as the idea that traders on the long side of a market wind up holding the short end of the stick that is they receive little or none of the gains from trade consider for instance the classic setting in which b identical buyers each with unit demands for an indivisible homogeneous good face s identical sellers each with one unit of the good for sale it is well known that in a broad class of one shot trading games all of the surplus in this setting goes to the short side of the market in equilibrium that is if b s buyers bid the price up to their reservation value often it is only when b s that market institutions the rules of the game have any bearing on the equilibrium division of surplus this classic result is somewhat brittle because of the discontinuity in the terms of trade when moving from positive to negative levels of excess demand its logic is familiar however from bertrand competition and it is very compelling the option value to an agent frozen out of a trade in a one shot market game is his reservation payoff of zero any outcome that confers nonzero surplus to a long side agent cannot be sustained in equilibrium because all of the long side agents who would otherwise be frozen out possess a strict incentive to undercut

markets with search friction and the dmp model dale t mortensen delivered his prize lecture on 8 december 2010 at aula magna stockholm university this abstract was borrowed from another version of this item

search intensity directed search and the wage distribution we propose a search equilibrium model in which homogenous rms post wages along with a vacancy to attract job seekers while homogenous unemployed workers invest in costly job seeking the key innovation relies on the organization of the search market and the search behavior of the job seekers the search market is continuously segmented by wage level individuals can spread their search investment over the di erent sub markets and search intensity has marginal decreasing returns on each sub market we show that there exists a non degenerate equilibrium wage distribution the density of this wage distribution is increasing at low wages and decreasing at high wages under additional restrictions it is hump shaped and it can be right tailed our results are illustrated by an example originating a beta wage distribution

on the inefficiency of matching models of unemployment with heterogeneous workers and jobs when firms rank their applicants in a circular matching model with bargained wages firms rank their applicants and pick the most suitable one job creation appears to lower the average output as firms do not internalize this effect there are too many jobs in a laissez faire equilibrium under the hosios condition by contrast job rejection is efficient for the equilibrium value of market tightness consequently introducing unemployment compensation raises the aggregate income by lowering market tightness due to the isomorphism between the two models these results extend to match specific productivities however competitive search restores market efficiency

computers productivity and input substitution i introduction the last two decades has been a puzzling time for many productivity analysts while computer prices fell at extraordinary rates and firms invested hundreds of billions of dollars in new computer equipment aggregate productivity growth remained sluggish this computer productivity paradox has generated a large literature that examines the economic impact of the computer revolution 1 this paper offers a simple solution to the computer productivity paradox by making careful distinction between computers as an output from one sector and an input to other sectors data for 35 manufacturing and service sectors for 1947 1991 show that sectoral differences are crucial in understanding the impact of computers aggregate analysis is inappropriate since it obscures basic distinctions between a shifting production function in the computer producing sector multi factor productivity growth and movements along production functions in the computer using sectors substitution and capital accumulation once these differences are isolated the growth impact of computers is readily observable the computer producing sector experienced fundamental technological progress and now produces cheaper better computers the sectoral data show this as rapid multi factor productivity mfp growth for 1973 1991 although aggregate mfp growth remains below historic averages the computer producing sector has clearly done its part mfp growth in this sector is many times the economy average and has contributed over one third of aggregate mfp growth for 19811991 the sectoral detail shows that the slowdown in aggregate productivity would have been much more severe were it not for such large mfp gains in the computer producing sector for the other sectors of the economy computers affect growth in a more traditional although less glamorous way when the price of real computing power fell so dramatically in the 1970s and 1980s firms responded by substituting away from relatively expensive labor and non computer capital and investing heavily in cheap computers for these sectors the computer revolution affects output growth not by raising mfp but by inducing firms to accumulate computers at extraordinary rates real computer services for example grew in excess of 20 per year in 14 out of 35 sectors for 1973 1991 although virtually all sectors are rapidly accumulating computer equipment computers remain small in levels in 1991 for example computer investment was only 10 of private fixed investment so the growth contribution of computers remains small relative to sectoral aggregates of labor and non computer capital the rapid rates of accumulation however are clearly making computers a more important source of growth across sectors with this heavy investment also came the wide spread expectation that computers would fundamentally alter the way firms operate and lead to higher mfp the reality has been very different as the most computer intensive sectors show steep declines in mfp growth after 1973 with three quarters of all computers concentrated in three service sectors trade fire and other services however this finding must be interpreted with caution as griliches 1994 notes output in these sectors is largely unmeasurable and thus mfp growth will be understated nonetheless it is quite reasonable that even computer using sectors where output is easier to measure show no mfp gains computer investment creates a capital input that enters the production function like any other purchased input since constant quality deflators embody productivity improvements in investment the direct impact is seen through the rapid capital accumulation only if the adoption of computers leads to production externalities or spillovers would computer investment also increase mfp growth the data however show no evidence of this ii computers and growth the national statistics most clearly show the computer revolution in the investment data

demand shocks and open economy puzzles abstract we pose good markets frictions on top of an otherwise standard two country international real business cycle irbc model shopping for goods takes effort which prevents perfect matching between customers and producers an increase in search effort implies increased measured productivity demand shocks increase expenditures and search effort simultaneously increasing output consumption productivity and the trade deficit and appreciating the real exchange rate thus we solve the backus smith puzzle and we show that the cross country correlation of consumption is higher than that of output standard irbc models cannot account for these puzzles along with movements in tfp

regulation with wage bargaining in many regulated industries labour unions are strong and there is clear empirical evidence of labour rent sharing in this paper we study optimal regulation in a model in which wages are determined endogenously by wage bargaining at the firm level a seemingly robust conclusion at least when worker bargaining power is considerable is that incentives for cost efficiency should be stronger than in the standard case in which wages do not depend on the regulatory regime

taxation and redistribution of residual income inequality this paper studies the optimal redistribution of income inequality caused by the presence of search and matching frictions in the labor market we study this problem in the context of a directed search model of the labor market populated by homogeneous workers and heterogeneous firms the optimal redistribution can be attained using a positive unemployment benefit and an increasing and regressive labor income tax the positive unemployment benefit serves the purpose of lowering the search risk faced by workers the increasing and regressive labor tax serves the purpose of aligning the cost to the firm of attracting an additional applicant with the value of an application to society

u s economic growth at the industry level the u s economy has expanded rapidly in recent years with total factor productivity the source of growth most closely identified with technological gains rising sharply since the mid 1990 s see e g bureau of labor statistics 1999 william gullickson and michael j harper 1999 mun s ho et al 1999 daniel e sichel 1999 this strong aggregate performance and the well documented explosion of investment in computers and other high tech equipment have led many to believe that the united states has experienced a permanent technology led growth revival it is essential however to disaggregate estimates of economic growth to the industry level to understand the new trends in the u s economy productivity growth the ability to produce more outputs from the same inputs differs widely among industries for the economy as a whole negative productivity growth in one industry can offset positive productivity growth in another and jorgenson 1990 shows that a measure of productivity based solely on aggregate data is valid only under very stringent conditions we avoid the limitations of an aggregate measure of productivity by decomposing u s growth across industries for the period 1958 1996 by breaking down the u s economy into 37 industries 35 private industries private households and general government we identify the contribution of each industry to aggregate productivity growth this enables us to isolate the underlying sources of gains in productivity and provides a better understanding of the forces driving the u s economy economy wide productivity from an aggregate production function increased 0 45 percent per year during 1958 1996 while methodology developed by evsey domar 1961 for aggregating over industries yields an aggregate estimate of 0 48 percent over the same period however industry productivity growth ranged from 1 98 percent in electronic and electric equipment to 20 52 percent in government enterprises highlighting fundamental differences in technology and productivity growth across industries these results show that the aggregate production function provides a reasonable estimate of productivity trends over long periods but also masks important differences among industries

efficient learning and job turnover in the labor market this article nests a continuous time learning model a la jovanovic journal of political economy 92 1984 108 22 into a directed on the job search framework we prove that the socially efficient allocation is separable that is the workers value functions and optimal controls are independent of both the distribution of workers across their current match qualities and the unemployment rate we characterize the dynamics of job transitions in the efficient allocation furthermore when the matching technology is linear our numerical results show that increasing the vacancy creation cost and the speed of learning have ambiguous effects on the unemployment rate and aggregate job transition

employment inequality why do the low skilled work less now abstract low skilled prime age men are less likely to be employed than high skilled prime age men and the differential has increased since the 1970s i build a search model encompassing three explanations 1 automation and trade reduced the demand for low skilled workers 2 health welfare and recreational gaming computer technology reduced the supply of low skilled workers and 3 factors affecting job search such as online job boards reduced frictions for high skilled workers i find a shift in demand away from low skilled workers was the leading cause a shift in supply had little effect and search frictions actually reduced employment inequality

competitive screening under heterogeneous information we study the interplay between informational frictions and second degree price discrimination our theory recognizes that consumers differ in their tastes for quality as well as in the information they possess about available offers which leads to dispersion over price quality menus in equilibrium while firms are ex ante identical we show that their menus are ordered so that more generous menus leave more surplus to consumers of all valuations we explore the cross section of equilibrium menus and variations in market conditions to generate empirical predictions on prices qualities and markups across firms and within a firm s product line for instance more competition may raise prices for low quality goods yet consumers are better off as the qualities they receive also increase the predictions of our model illuminate empirical findings in many markets such as those for cell phone plans yellow pages advertising cable tv and air travel

holdups and efficiency with search frictions a natural holdup problem arises in a market with search frictions firms have to make a range of investments before finding their employees and larger investments translate into higher wages in particular when wages are determined by ex post bargaining the equilibrium is always inefficient recognizing that capital intensive production relations have to pay higher wages firms reduce their investments this can only be prevented by removing all the bargaining power from the workers but this in turn depresses wages below their social product and creates excessive entry of firms in contrast to this benchmark we show that efficiency is achieved when firms post wages and workers can direct their search toward more attractive offers this efficiency result generalizes to an environment with imperfect information where workers only observe a few of the equilibrium wage offers we show that the underlying reason for efficiency is not wage posting per se but the ability of workers to direct their search toward more capital intensive jobs

informative price advertising in a sequential search model the purpose of this paper is to study the role and implications of price advertising when shopping trips are costly to consumers to do so we introduce advertising into an optimal sequential search model information about prices is both gathered by consumers and disseminated by firms consumers search sequentially and stores advertise with various intensity when it is in their interest to do so our model has a unique equilibrium exhibiting priee dispersion the model generates predictions about the shape of the price distribution and firms advertising behavior we explore the effects of entry and find that when initial advertising costs at zero level of effort are precisely zero entry drives the equilibrium to the perfectly competitive outcome however when initial marginal advertising costs are positive entry drives prices higher and while the informed consumers almost surely locate competitive prices welfare does not necessarily increase finally we compare the effectiveness of the two informational channels when advertising costs shrink prices become competitive however when search costs shrink prices remain bounded above marginal production costs

should buyers or sellers organize trade in a frictional market to answer the question in the title this article characterizes the socially efficient organization of the market with search frictions the efficient organization depends on the relative elasticity in the supply between the two sides of the market the costs of participating in the market and organizing trade and the a symmetry in matching we also show that the social optimum can be implemented by a realistic market equilibrium where the organizers set up trading sites to direct the other side s search the results provide a unified explanation for why trade has often been organized by sellers in the goods market by buyers firms in the labor market and by both sides in the asset market the analysis also sheds light on how the efficient market organization can change with innovations such as e commerce and just in time production

search mismatch and unemployment abstract this paper explores the efficiency of the equilibrium allocation in a matching model with heterogeneous workers and jobs in the basic setup there are two types of workers with different skill levels both types can perform the simple tasks of unskilled jobs while the complex tasks of skilled jobs require a high ability worker we demonstrate that the equilibrium outcome with random search and ex post bargaining is never efficient under the hosios condition the average wage is correct but bargaining compresses the wage distribution relative to workers shadow values this feature distorts the relative profits of jobs making it too attractive for firms to create skilled jobs furthermore due to the low skill premium the high ability workers may accept too many jobs finally in an extension we show that the introduction of separate markets for the two types of jobs is not sufficient to guarantee efficiency

ex ante price offers in matching games non steady states a matching problem is considered in which sellers can publicly commit to a trading price that differs from the price at which buyers expect to trade elsewhere in the market when demand and supply are nearly equal the equilibrium ex ante price offer lies below the price associated with the nash bargaining split this relationship reverses when the level of excess demand is large sellers always have an incentive to make ex ante offers when prices elsewhere are determined by nash bargaining this can be interpreted to mean that nash bargaining is an unstable pricing institution copyright 1991 by the econometric society

stock flow matching and the performance of the labor market we estimate outflow equations for vacancies and unemployed workers in britain departing from the stock based analysis of matching in two ways first we deal with the temporal aggregation problem that arises when discrete time data are used to describe continuous time processes second we allow for a stock flow matching mechanism in which the stock of traders on one side of the market matches with the flow of traders on the other side our estimates are in line with the predictions of stock flow matching in terms of higher exit rates of flows and of matching combinations between labor market stocks and flows furthermore employer search effectiveness did not seem to decline between the 1960s and the 1990s nevertheless some deterioration in worker search effectiveness is detected however less severe than that implied by previous stock based work

income tax evasion labour supply and the equity efficiency tradeoff abstract this paper is an attempt to incorporate tax evasion into the analysis of optimum income taxation a model of variable labour supply with tax evasion is used to derive supply functions for labour in regular and irregular markets given taxpayer behaviour the government chooses tax rates penalties and the probability of detection to maximize a utilitarian social welfare function the results consist in the derivation of a formula for the optimum marginal tax rate and a characterization of the factors determining the choice between the penalty rate and the probability of detection as instruments for the control of tax evasion

long term partnership formation marriage and employment of course marriage and employment are different nevertheless a worker looking for a job a rm looking for worker or a single person looking for a marriage partner face similar problems as all are seeking a long term partner indeed forming long term partnerships is a common occurrence in life there are many other examples business people search for other business people to form a pro table relationship bridge players seek to nd a suitable partners students search for a good university we would all like to nd a good friend etc the problem becomes signi cant if there are substantial differences in the return obtained from forming a partnership with different partners for example employers differ in the wages they offer or in the work environment they provide in such a situation a worker may reject some job offers similarly as many have learned to their cost some make better marriage partners than others the problem is two sided while a worker is evaluating a potential employer the employer is also evaluating the worker it is this two sided aspect of the problem that generates a signi cant interest a worker s willingness to accept employment at a rm depends not only on the characteristics of the rm but also the other possible options open to the worker the better an individual s opportunities elsewhere the more selective he or she will be in evaluating a potential partnership an academic who believes harvard may make an offer in the near future will be more selective in evaluating offers from lesser universities in this way expectations play a role if a single man believes that few if any women will nd him an acceptable marriage partner then he may accept the rst opportunity that presents itself partnership formation typically does not comply with a classic market situation where all participants know everything and all trades take place at zero cost finding a job nding a husband or wife or nding a business partner is a time consuming activity where opportunities typically arrive over time at uncertain intervals of time of course we can act in ways that in uence the arrival rate of potential partner workers go to employment agencies or read help wanted advertisements in newspapers singles of a certain age go to discos or join tennis clubs the literature on search and matching sm see mortensen 1982 and pissarides 1990 for early examples 1 provides an excellent framework for the economic journal 109 june f307 f334 royal economic society 1999 published by blackwell publishers 108 cowley road oxford ox4 1jf uk and 350 main street malden ma 02148 usa

directed search and optimal production abstract i consider a model of directed search where strategic sellers advertise general trading mechanisms a mechanism determines the number of buyers that will get served and the side payments as a function of ex post realized demand buyers observe these advertisements and visit one seller without being able to coordinate their visiting strategies despite the oligopolistic nature of the model all symmetric equilibria are constrained efficient in small markets multiple equilibria exist that are not payoff equivalent this indeterminacy vanishes as the market grows large i provide closed form solutions for equilibrium prices profits and the matching function under any parameter values

directed search with multi vacancy firms abstract i construct a directed search model in which firms decide whether to enter a market and how many positions to create within this framework the number of firms and the size of each firm are determined endogenously wages play an allocative role in the matching process and the frictions inherent in this process derive from the equilibrium behavior of workers and firms i characterize the unique equilibrium comparative statics generate testable implications for cross sectional variation in matching efficiency as well as the dynamic behavior of vacancies and unemployment moreover allowing for ex ante heterogeneity across firms the model can easily and naturally generate the observed relationship between firm size wages profitability and hiring

competitive search equilibrium with multidimensional heterogeneity and two sided ex ante investments abstract we analyze a competitive price taking search model where workers and firms make costly investments e g in education and physical capital respectively before they enter the labor market the environment features transferable utility and symmetric information a key novelty with respect to existing work is that we allow for multidimensional heterogeneity on both sides of the market the probabilities of finding and filling different jobs and the corresponding wages are determined endogenously in equilibrium we show that constrained efficient allocations can be determined as optimal solutions to a linear programming problem whereas the prices supporting these allocations and the associated expected payoffs for workers and firms correspond to the solutions of the dual of that linear program we use this characterization to show that an equilibrium exists and is constrained efficient under very general conditions the fact that linear programming techniques are used for the structural estimation of frictionless matching models suggests that our framework is potentially useful for empirical studies of labor markets and other markets where search frictions are prevalent

search costs and efficiency do unemployed workers search enough many labor market policies affect the marginal benefits and costs of job search the impact and desirability of such policies depend on the distribution of search costs in this paper we provide an equilibrium framework for identifying the distribution of search costs and we apply it to the dutch labor market in our model the wage distribution job search intensities and firm entry are simultaneously determined in market equilibrium given the distribution of search intensities which we directly observe we calibrate the search cost distribution and the flow value of non market time these values are then used to derive the socially optimal firm entry rates and distribution of job search intensities from a social point of view some unemployed workers search too little due to a hold up problem while other unemployed workers search too much due to coordination frictions and rent seeking behavior our results indicate that jointly increasing unemployment benefits and the sanctions for unemployed workers who do not search at all can be welfare improving

wage differentials discrimination and efficiency abstract i analyze a large labor market where homogeneous firms post wages to direct the search of workers who differ in productivity i show that the model has a unique equilibrium the wage differential depends positively on the workers productivity differential only when the latter is large when the productivity differential is small high productivity workers get a lower wage than low productivity workers this reverse wage differential remains even when the productivity differential shrinks to zero however the equilibrium is socially efficient high productivity workers always get the employment priority and higher expected wages than low productivity workers although discrimination in terms of expected wages does not exist conventional measures are likely to incorrectly find discrimination in the model

does competition solve the hold up problem in an environment in which heterogeneous buyers and sellers undertake ex ante investments the presence of market competition for matches provides incentives for investment but may leave inefficiencies namely hold up and coordination problems this paper shows using an explicitly non cooperative model that when matching is assortative and investments precede market competition buyers investments are constrained efficient while sellers marginally underinvest with respect to what would be constrained efficient however the overall extent of this inefficiency may be large multiple equilibria may arise one equilibrium is characterized by efficient matches but there can be additional equilibria with coordination failures

a walrasian theory of markets with adverse selection the paper describes a walrasian theory of markets with adverse selection and shows how refinements of equilibrium can be used to characterize uniquely the equilibrium outcome equilibrium exists under standard conditions it is shown that under certain conditions a stable set exists and is contained in a connected set of equilibria for generic models there exists a stable outcome that is all the equilibria in the stable set have the same outcome these ideas are applied to markets with one sided and two sided uncertainty under standard monotonicity conditions it is shown that the stable outcome is separating and implies a particular pattern of matches of buyers and sellers

pareto inefficiency of market economies search and efficiency wage models this paper shows that market economies with search and in which wages are affected by efficiency wage considerations are not constrained pareto efficient wages are not set at pareto efficient levels nor is the level of employment unemployment pareto efficient we identify the nature of the biases and the welfare improving government interventions this abstract was borrowed from another version of this item

it s about time implications of the period length in an equilibrium search model empirical evidence suggests that transitions between employment states are highly clustered around the first day of each workweek or month i analyze the effect of this phenomenon by presenting an equilibrium search model in which the period length is a parameter determining the degree of clustering infinitesimally short periods result in a continuous time model with bilateral meetings whereas longer time periods introduce the possibility of recall or simultaneity of job offers in this environment i show that the period length has a profound effect on equilibrium outcomes including the unemployment rate unemployment duration and the cross sectional wage distribution

strategic bargaining and competitive bidding in a dynamic market equilibrium this paper extends the bargaining and matching literature such as rubinstein 1985 and gale 1986 and 1987 by considering a new matching process we assume that a central information agency exists such as job centres and newspapers in the labour market or real estate agents in the housing market which puts potential traders into direct contact with each other with agent heterogeneity equilibrium trade is characterized by existing traders on the other side since existing traders have already sampled and rejected each other two procedures of trade coexist namely strategic bilateral bargaining and a competitive bidding process depending on the number of potential matches a new trader obtains we characterize the unique symmetric markov perfect equilibrium to this stochastic trading game

pricing and signaling with frictions abstract we study a market where each seller chooses the quality and price of goods and the number of selling sites observing sellers choices of prices and sites but not quality buyers choose which site to visit a seller s choices of prices can direct buyers search and signal quality a unique equilibrium exists and is separating when the quality differential is large the equilibrium implements the efficient allocation with public information otherwise the quality of goods and or the number of sites created is inefficient due to a conflict between the search directing and signaling roles of prices