General training by firms, apprentice contracts, and public policy

Workers will not pay for general on-the-job training if contracts are not enforceable. Firms may if there are mobility frictions. Private information about worker productivities, however, prevents workers who quit receiving their marginal products elsewhere. Their new employers then receive external benefits from their training. In this paper, training firms increase profits by offering apprenticeships which commit firms to high wages for those trainees retained on completion. At these high wages, only good workers are retained. This signals their productivity and reduces the external benefits if they subsequently quit. Regulation of apprenticeship length (a historically important feature) enhances efficiency. Appropriate subsidies enhance it further.     

Evaluating the performance of the search and matching model

Does the search and matching model fit aggregate U.S. labor market data? While the model has become an important tool of macroeconomic analysis, recent literature pointed to some significant failures in accounting for the data. This paper aims to answer two questions: (i) Does the model fit the data, and, if so, on what dimensions? (ii) Does the data “fit” the model, i.e. what are the data which are relevant to be explained by the model?The analysis shows that the model fits certain specifications of the data on many dimensions, though not on all. This includes capturing the high persistence and high volatility of most of the key variables, the negative co-variation of unemployment and vacancies, and the behavior of the worker job finding rate. A key role in this fit is played by the convexity of hiring costs and the stochastic properties of the separation rate. The latter is a major component of the rate discounting the future value of the job-worker match.The paper offers a workable, empirically grounded version of the model for the analysis of aggregate U.S. labor market dynamics.     

Gender differences in self‐employment

This paper examines the factors that influence transitions into self‐employment, paying particular attention to gender differences. We find that: (i) men are more responsive to the wage differential between wage/salaried employment and self‐employment; (ii) liquidity constraints are more important for men; and (iii) the link between father's self‐employment status and the probability of self‐employment is stronger for men. Taken together, these results suggest that, for women, self‐employment is a closer substitute for part‐time work and labour‐market inactivity than it is for men. We attribute such differences to the different labour market opportunities and occupational strategies of women.     

Employment shifts, economic reform and the changes in public/private sector wages in Mexico: 1987–1997

Over the last decade, the public sector in Mexico experienced substantial fiscal reform, divestiture of public enterprises, and the elimination of many regulations affecting pay and employment. This study analyzes the changes in the public/private sector differences in wages during the 1987–1997 period. The results from analyzing microdata from the Encuesta Nacional de Empleo Urbano show that relative public sector wages increased from 1987 to 1997. Most of the relative wage increase in the public sector can be explained by increases in the price of skills and by changes in sorting across sectors. The results have important public policy implications since they suggest that public sector workers earn more and their wages have grown faster than those of their private sector counterparts. As such, policies contemplating public sector reform should take into account the effect of these measures on the inter-sectoral income distribution and the overall economic growth. First version received: April 2000/Final version received: December 2000     

A microfoundation for increasing returns in human capital accumulation and the under-participation trap

This paper considers educational investment, wages and hours of market work in an imperfectly competitive labour market with heterogeneous workers and home production. It investigates the degree to which there might be both underemployment in the labour market and underinvestment in education. A central insight is that the ex post participation decision of workers endogeneously generates increasing marginal returns to education. Although equilibrium implies underinvestment in education, optimal policy is not to subsidise education. Instead it is to subsidise labour market participation which we argue might be efficiently targeted as state-provided childcare support.     

Sample attrition and labor force dynamics: Evidence from the Spanish labor force survey

In this paper we examine a number of issues that arise in investigating labor force dynamics using the Spanish Labor Force Survey (EPA). These issues are by no means specific to the Spanish case and apply to most European-style labor force surveys. Our main conclusions may be summarized as follows. First, survey nonresponse cannot be neglected. Second, the EPA tends to underestimate employment and participation of high-educated young people, and to overestimate those of the low-educated elderly. Finally, we find little evidence that attrition causes important selection biases in estimating quarterly transition probabilities.     

A mechanism implementing the proportional solution

We consider the problem of a commonly owned technology which transforms a single input into a single output. We are interested in implementing a social choice rule called theproportional solution. We introduce a mechanism which implements the proportional solution in Nash, strong (Nash) and undominated Nash equilibria. In the mechanism each agent announces only two numbers which can be interpreted as the total output and her share of the total input-output combination. This paper was originally titled "Doubly implementing the proportional solution." I would like to thank my advisor William Thomson for his detailed comments and suggestions. I would also like to thank Jeffrey Banks and Sung-Whee Shin for their comments. Two anonymous referees and an editor’s comments improved this paper substantially.     

Entry regulation as a barrier to entrepreneurship

Using a comprehensive database of European firms, we study the effect of market entry regulations on the creation of new limited-liability firms, the average size of entrants, and the growth of incumbent firms. We find that costly regulations hamper the creation of new firms, especially in industries that should naturally have high entry. These regulations also force new entrants to be larger and cause incumbent firms in naturally high-entry industries to grow more slowly. Our results hold even when we correct for the availability of financing, the degree of protection of intellectual property, and labor regulations.     

利用闪存芯片作存储器的单片机应用系统

在测量及测试应用系统中,为使现场采集的数据在突发性的掉电过程中不被丢失,且能长时间的保持,可采用32M位闪存芯片KM29N32000TS作为存储器。本文以AT89S51单片机为例介绍它在单片机系统中的硬件连接和软件编程方法。     

Human capital and earnings distribution dynamics

Earnings heterogeneity plays a crucial role in modern macroeconomics. We document that mean earnings and measures of earnings dispersion and skewness all increase in US data over most of the working life-cycle for a typical cohort as the cohort ages. We show that (i) a human capital model can replicate these properties from the right distribution of initial human capital and learning ability, (ii) differences in learning ability are essential to produce an increase in earnings dispersion over the life cycle and (iii) differences in learning ability account for the bulk of the variation in the present value of earnings across agents. These findings emphasize the need to further understand the role and origins of initial conditions.