malawi s agricultural development a success story abstract at a time when attention was focused on africa s poor agricultural performance malawi demonstrated a capacity not only to feed itself but to produce a surplus for export during the periods covered in this paper its agricultural growth exceeded that of most african countries and compared favorably with success stories on the continent this research focuses on malawi s recent performance with particular attention on trends in the provision of essential agro support services credit extension and farmer training and input supply and marketing trends in these services are examined first at the national level and then at the district level while overall trends indicate substantial progress district level data reveal extensive unevenness moreover at the farm level census data on farmer training and technology utilization show fewer benefits to female operators and smaller farmers important elements of developmentally oriented infrastructure and services have been put in place and are functioning better than in most african countries this is important in terms of longer term agricultural development prospects there is ample evidence however that malawi s progress has not spread across different segments of the farm population or agriculture development districts both the unevenness and overall progress have been heavily influenced by donor support

wages experience and seniority in this paper we study the sources of wage growth we identify the contribution to such growth of general sector specific and firm specific human capital our results are interpretable within the context of a model where the returns to human capital may be heterogeneous and where firms may offer different combinations of entry level wages and firm specific human capital development we allow for the possibility that wages are match specific and that workers move jobs as a result of identifying a better match to estimate the average returns to experience sector tenure and firm specific tenure within this context we develop an identification strategy which relies on the use of firm closures our data source is a new and unique administrative data set for germany that includes complete work histories as well as individual characteristics we find positive returns to experience and firm tenure for skilled workers the returns to experience for unskilled workers are small and insignificant after 2 years of experience their returns to sector tenure are also zero however their returns to firm tenure are substantial in this paper we study the growth of wages of young workers in germany knowing the extent and reasons for individual wage growth over the life cycle is important for a number of areas in economics just to mention two examples first it is a key element to understanding and designing active labour market programmes many such programmes offer temporary and often subsidized work opportunities examples are the new deal in the u k and the swedish programmes as well as a number of programmes in germany these programmes are based on the assumption that general skills are sufficiently enhanced while working so as to render the workers employable without a wage subsidy thus the success of these programmes depends on how skills improve on the job for the target population and whether this skill enhancement is transferable across jobs second it is a key to understanding the benefits and costs of job mobility this in turn matters for a number of policy issues including the design of pension policies relating for example to final salary schemes as a result of this widespread interest a large body of empirical research has focused on obtaining estimates for the returns of experience and seniority 1 our study uses a new and unique administrative data set with a number of features that are important for our analysis and allow us to avoid many problems encountered in earlier work in this field in our model wages grow due to learning by doing which may be heterogeneous across individuals moreover since firms offer different career profiles and because we allow for match specific effects on wages investments take the form of searching for the firm with the most desirable learning by doing characteristics career structure 2

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

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

search theory the 2010 nobel memorial prize in economic sciences this paper surveys search theory with an emphasis on the contributions of the 2010 laureates for the nobel memorial prize in economic sciences peter diamond dale mortensen and christopher pissarides

search intensity job advertising and efficiency this paper demonstrates that if both firms and workers search the other side of the market for job matches the equilibrium rate of unemployment is likely to be too high both sides ignore a positive externality of their search when they establish a job match they remove from the market a job searcher so they save society his search costs i show that there is no feasible wage rate that can internalize this externality under fairly weak restrictions on the technology of search

asymmetric information and search frictions a neutrality result this paper integrates asymmetric information between firms into a canonical model of on the job search workers are heterogeneous in ability but not all employers observe a worker s type wage dispersion caused by search frictions makes the equilibrium wage distribution insensitive to informational asymmetries hence the equilibrium outcome may be the same as when a worker s ability is known to every firm the supportability of the full information outcome depends on market parameters related to productivity knowledge and search the theoretical results elucidate an empirical puzzle about demographic differences in asymmetric information between employers

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

the effectiveness of structural adjustment lending initial evidence from malawi abstract the world bank s new programs of structural adjustment lending are likely to prove most effective with those governments which demonstrate shared ideals in their approach to economic adjustment and policy reform malawi has long been regarded as a country placing great reliance on the market in resource allocation showing restraint in public sector expansion and retaining a strong export orientation the balance of payments difficulties and the deterioration in economic circumstances which began in 1980 did not arise solely from external shocks but the structural adjustment lending programs introduced in 1981 as a means of easing the painful reform process found root in a fertile and responsive policy environment this paper chronicles the first two sals to malawi reviewing in particular the specific policy reforms advocated and required by the bank the extent of their implementation and the provisional effects on the malawi economy

public sector wage policy and labor market equilibrium a structural model we develop and estimate a structural model that incorporates a sizable public sector in a labor market with search frictions the wage distribution and the employment rate in the public sector are taken as exogenous policy parameters overall wage distribution and employment rate are determined within the model taking into account the private sector s endogenous response to public sector employment policies job turnover is sector specific and transitions between sectors depend on the worker s decision to accept alternative employment in the same or different sector by comparing the value of employment in the current and prospective jobs the model is estimated on british data by a method of moments we use the model to simulate the impact of various counterfactual public sector wage and employment policies

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

directed search with multiple job applications we develop an equilibrium directed search model of the labor market where workers can simultaneously apply for multiple jobs the main result is that all equilibria exhibit wage dispersion despite the fact that workers and firms are homogeneous wage dispersion is driven by the simultaneity of application choice risk neutral workers apply for both safe and risky jobs the former yield a high probability of a job oer but for low pay and act as a fallback option the latter provide with higher potential payo but are harder to get furthermore the density of posted wages is decreasing consistent with stylized facts unlike most directed search models the equilibria are not constrained ecient

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

a continuous model for multistore competitive location this paper presents a simple model to determine the location strategies of two retail firms planning to open a number of stores in a geographical market firms try to maximize their profit under a leader follower type competition in which the number of stores is made endogenous by the introduction of fixed costs a novel methodology is developed in which firms strategies are defined in terms of their location densities this methodology leads to a model that is solvable analytically and to several results on competitive location strategies first it is shown that if the follower decides to enter a market he enters at least as strongly as the leader second the leader can effectively deter entry even if she is severely cost disadvantaged however in some cases the leader is better off by allowing the follower to enter the market third the leader may also let the follower enter the market in some situations where she has a cost advantage it is also shown that in situations where both firms enter the market their location strategies are quite insensitive to model parameters

the efficiency of search under competition and monopsony this paper compares monopsonistic and competitive search equilibria while the competitive equilibrium is efficient the monopsonistic equilibrium is not there is too much search and the employment rate is too low

bertrand equilibrium with capacity constraints and restricted mobility this paper considers price competition among firms when there are capacity constraints and buyers have limited ability to visit firms a natural method of allocating buyers among firms arises in the equilibrium of the buyers search game sufficient conditions are given under which the buyers equilibrium varies continuously with the prices charged by firms capacity constraints are used to guarantee that this ensures existence of mixed strategy equilibria for the pricing game played by sellers we show that natural pure strategy equilibria arise when the game is made large in appropriate ways since bertrand s criticism of cournot it has been known that models where sellers compete with prices may have undesirable properties when the commodities traded are homogenous in the simplest models with constant marginal costs price may be driven down to the competitive level even when there are only two firms more problematic if sellers are subject to capacity constraints nash in prices equilibrium may not exist at all these problems all arise because of a discontinuity in firms profit functions that arises when the prices of two or more firms are equal there have been many attempts to resolve this problem the simplest is to constrain sellers prices to be equal and to force them to compete in quantities this is the basis of most of the literature on monopolistic competi

structural change in malawi since independence consequences of a development strategy based on large scale agriculture abstract this paper investigates the nature of the structural change which has occured in the malawian economy since independence and identifies key policies pursued by the government which it is argued have been decisive in shaping this development the salient feature of structural change is shown to be the rapid growth of large scale agriculture associated with an equally rapid transfer of labour into wage employment and a decline in the importance of peasant production the implications of these changes for living standards and future development and policy are considered

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

research note vertical information sharing in a volatile market when demand is uncertain manufacturers and retailers often have private information on future demand and such information asymmetry impacts strategic interaction in distribution channels in this paper we investigate a channel consisting of a manufacturer and a downstream retailer facing a product market characterized by short product life uncertain demand and price rigidity assuming the firms have asymmetric information about the demand volatility we examine the potential benefits of sharing information and contracts that facilitate such cooperation we conclude that under a wholesale price regime information sharing might not improve channel profits when the retailer underestimates the demand volatility but the manufacturer does not although information sharing is always beneficial under a two part tariff regime it is in general not sufficient to achieve sharing and additional contractual arrangements are necessary the contract types we consider to facilitate sharing are profit sharing and buyback contracts

does large price discrimination imply great market power abstract a simple model demonstrates that there is no theoretical connection between the extent of price discrimination and the extent of market power

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

efficiency in employment based health insurance the potential for supra marginal cost pricing currently the majority if privately insured individuals in the u s are insured through their employers this has significant implications for competition and the ability qf a competitive insurance industry to assure marginal cost pricing the central barrier to competition arises when employers restrict their employees ability to select among insurance carriers several models 4 insurer proft maximization are explored which demonstrate that supra marginal cost pricing is likely to persist euen when the insurance market appears cornpetitiue

agricultural policy in tropical africa is a turnaround possible abstract the food crisis in africa has entered our living rooms through television and the press why is per capita agricultural production lower now than at independence in the early 1960s this article examines the factors responsible and outlines some solutions both external and internal factors have converged to create the crisis low prices to farmers to placate vocal urban consumers inefficient high cost marketing boards governments neglect of agriculture in favor of industry over valued exchange rates lack of foreign exchange and increasing debt burdens externally the depressed world market decreased demand for africa s exports and contributed to the stagnation of the economics drought a population growth rate approaching 3 year and a shortage of human capital added to the crisis

wage tenure contracts in a frictional labour market firms strategies for recruitment and retention a common assumption in equilibrium search and matching models of the labour market is that each firm posts a wage to be paid to any worker hired this paper considers the implications of firms posting contracts in a random matching model with on the job search more complex contracts enable firms to address both recruitment and retention problems by for example increasing the wage with tenure the effect on the labour market is to reduce turnover below the level required for efficient matching of workers to firms copyright 2004 wiley blackwell

price discrimination in competitive markets we present models in which price discrimination in the context of a two part price can occur in some competitive markets purchases take place in groups which choose which firms to patronize while firms are perfectly competitive with respect to groups they have some market power over individual consumers who are constrained by their groups choices we find that firms will charge an entry fee that is below marginal cost and the second part of the price is marked up above marginal cost the markup not only is positive but increases with the quality of the product

the unemployment volatility puzzle is wage stickiness the answer i discuss the failure of the canonical search and matching model to match the cyclical volatility in the job finding rate i show that job creation in the model is influenced by wages in new matches i summarize microeconometric evidence and find that wages in new matches are volatile and consistent with the model s key predictions therefore explanations of the unemployment volatility puzzle have to preserve the cyclical volatility of wages i discuss a modification of the model based on fixed matching costs that can increase cyclical unemployment volatility and is consistent with wage flexibility in new matches

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

the cost of job loss this article identifies an equilibrium theory of wage formation and endogenous quit turnover in a labour market with on the job search where risk averse workers accumulate human capital through learning by doing and lose skills while unemployed optimal contracting implies the wage paid increases with experience and tenure indirect inference using german data determines the deep parameters of the model the estimated model not only reproduces the large and persistent fall in wages and earnings following job loss a new structural decomposition finds foregone human capital accumulation while unemployed is the worker s major cost of job loss

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

business cycles and labor market search the quantitative implications of labor market search for economic fluctuations are evaluated in the context of a real business cycle model incorporating labor market search into the model is found to improve its empirical performance along several dimensions in particular hours now fluctuate substantially more than wages and the contemporaneous correlation between hours and productivity falls in addition the model replicates the observation that output growth displays positive autocorrelation at short horizons overall the empirical results suggest that the labor market search environment embodies a quantitatively important propagation mechanism copyright 1996 by american economic association

pricing and matching with frictions suppose that n buyers each want one unit and m sellers each have one or more units of a good sellers post prices and then buyers choose sellers in symmetric equilibrium similar sellers all post one price and buyers randomize hence more or fewer buyers may arrive than a seller can accommodate we call this frictions we solve for prices and the endogenous matching function for finite n and m and consider the limit as n and m grow the matching function displays decreasing returns but converges to constant returns we argue that the standard matching function in the literature is misspecified and discuss implications for the beveridge curve

the effects of labour market policies in an economy with an informal sector in this article we build an equilibrium search and matching model of an economy with an informal sector our model extends mortensen and pissarides 1994 by allowing for ex ante worker heterogeneity with respect to formal sector productivity we use the model to analyse the effects of labour market policy on informal sector and formal sector output on the division of the workforce into unemployment informal sector employment and formal sector employment and on wages finally we examine the distributional implications of labour market policy specifically we analyse how labour market policy affects the distributions of wages and productivities across formal sector matches in this article we construct a search and matching model that we use to analyse the effects of labour market policies in an economy with a significant informal sector what we mean by an informal sector is a sector that is unregulated and hence not directly affected by labour market policies such as severance or payroll taxes we find that labour market policies that apply only to the formal sector nonetheless affect the size and the composition of employment in the informal sector this is important since there is substantial economic activity in the informal sector in many economies particularly in developing countries estimates for some latin american countries put the informal sector at more than 50 of the urban work force 1 the informal sector is also important in many transition countries as well as in some developed economies 2 although much of the literature treats the informal sector as a disadvantaged sector in a segmented labour market framework this interpretation is not consistent with recent empirical evidence from latin america under a segmented or dual labour market interpretation one would expect jobs to be rationed in the primary sector and workers to be in the secondary or informal sector involuntarily and to be queuing for formal sector jobs maloney 2004 presents evidence for several latin american countries that challenges this view and instead interprets the informal sector as an unregulated micro entrepreneurial sector similarly using data from the argentinian household survey pratap and quintin 2006 reject the notion that labour markets are segmented in the greater buenos aires area concluding that there is no evidence of a formal sector wage premium after controlling for individual and establishment we thank mauricio santamaria for stimulating conversations that inspired our interest in this topic we also thank bob hussey and fabien postel vinay as well as our editor steve pischke and two anonymous

occupational specificity of human capital we find that returns to occupational tenure are substantial everything else being constant 5 years of occupational tenure are associated with an increase in wages of 12 20 moreover when occupational experience is taken into account tenure with an industry or employer has relatively little importance in accounting for the wage one receives this finding is consistent with human capital being occupation specific

mobility costs frictional unemployment and efficiency with imperfect job information flows it is plausible that the distribution of job offerings becomes more attractive when there are more vacancies and more unemployed with word of mouth communication this condition is derived given this condition steady state equilibrium is not efficient with welfare increased by the introduction of unemployment compensation even though all agents are risk neutral in this way workers become more selective in the jobs they accept

equilibrium wage tenure contracts in this study we consider a labor market matching model where firms post wage tenure contracts and workers both employed and unemployed search for new job opportunities given workers are risk averse we establish there is a unique equilibrium in the environment considered although firms in the market make different offers in equilibrium all post a wage tenure contract that implies a worker s wage increases smoothly with tenure at the firm as firms make different offers there is job turnover as employed workers move jobs as the opportunity arises this implies the increase in a worker s wage can be due to job to job movements as well as wage tenure effects further there is a nondegenerate equilibrium distribution of initial wage offers that is differentiable on its support except for a mass point at the lowest initial wage we also show that relevant characteristics of the equilibrium can be written as explicit functions of preferences and the other market parameters

efficient unemployment insurance this paper constructs a tractable general equilibrium model of search with risk aversion an increase in risk aversion reduces wages unemployment and investment unemployment insurance has the opposite effect insured workers seek high wage jobs with high unemployment risk an economy with risk neutral workers achieves maximal output without any unemployment insurance but an economy with risk averse workers requires a positive level of unemployment insurance to maximize output therefore moderate unemployment insurance not only improves risk sharing but also increases output

rural credit markets and institutions in developing countries lessons for policy analysis from practice and modern theory this article presents evidence of the failure of government intervention in rural credit markets of ldcs in the past three decades it then shows how lessons for policy analysis can be drawn from modern theory particularly those theories focussing on credit rationing in competitive markets and interlinking of credit contracts with labor and land contracts the article outlines the policy implications of these theories and finds them insufficient to account for the empirical evidence it contends that a more systematic and rigorous analysis of institutions and institutional environments is essential for understanding and implementing effective policy reforms of rural credit markets it presents suggestions for undertaking such an analysis

a model of the natural rate of unemployment since the publication of edmund phelps volume the new macroeconomics has treated the labor market as a dynamic process of rational search by unemployed workers for available vacancies wages are viewed as at least potentially flexible though free contracting between workers and firms may lead to fixed wages in the short run imperfect information is a crucial element of the theory for it implies both a need for contracting and a need for rational search rather than simple market clearing in each period a positive rate of frictional unemployment may exist in equilibrium denoted as the natural rate this unemployment is due to the frictions in the search process and imperfections in information rather than to any deficiency in aggregate demand milton friedman defined the natural rate as the level that would be ground out by the walrasian system of general equilibrium equations provided there is embedded in them the actual structural characteristics of the labor and commodity markets including market imperfections stochastic variability in demands and supplies the cost of gathering information about job vacancies and labor availabilities the costs of mobility and so on p 8 this paper reexamines the micro foundations of the natural rate in a model of labor market equilibrium in which turnover flows and imperfect information are explicitly considered workers may quit their current jobs to enter the unemployment pool in order to search among available vacancies for a more preferred position firms economize on turnover by an appropriate wage policy

labor market equilibrium with rehiring consistent with the empirical evidence this article analyzes a labor market in which separations are not permanent and reactivated firms prefer to rehire former employees instead of seek new ones workers engage in job search due to the uncertain prospects of rehiring if firms can commit to wages contingent on rehiring they backload wages to provide incentives for workers to reduce their unobservable search effort under risk aversion and incomplete markets if productivity at reactivation is sufficiently high the tension between wage backloading and consumption smoothing leads to excessive search in equilibrium

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