Poverty Traps, Indeterminacy, and the Wealth Distribution

We consider a one-sector growth model in continuous time with a production externality and endogenous labor supply. There is a continuum of households who have identical preferences but differ with respect to their initial wealth. We show that there exist economies such that an indeterminate steady state exists for some wealth distribution but not for others. A second result is that a redistribution of wealth may drive the economy from a steady state with strictly positive output to a poverty trap in which output converges asymptotically to zero. These results indicate that differences in the wealth distribution may be responsible for drastic differences in the long-run standard of living. Journal of Economic Literature Classification Numbers: D31, D50, O41.     

Have Employment Relationships in the United States Become Less Stable?

There has been considerable debate as to whether job stability has declined in the United States. This paper uses data from the Survey of Income and Program Participation (SIPP) to examine the incidence of labor market turnover between 1986 and 1993. Specifically, we calculate one- and two-year separation rates and then analyze turnover by the source of separation. We find that the incidence of job separations did not increase over the period under investigation, but appears to have declined somewhat. When analyzing separations by reason, conditional on separating from an employer, we find little evidence of temporal changes in the composition of turnover that would indicate greater employment instability. Therefore, we do not find conclusive evidence that employment relationships have become more unstable in the recent past.      

Market clearing and derivative pricing

Summary. We develop a method of assigning unique prices to derivative securities, including options, in the continuous-time finance model developed in Raimondo (2001). In contrast with the martingale method of valuing options, which cannot distinguish among infinitely many possible option pricing processes for a given underlying securities price process when markets are dynamically incomplete, our option prices are uniquely determined in equilibrium in closed form as a function of the underlying economic data.Received: 14 April 2003, Revised: 7 January 2004, JEL Classification Numbers: G13, D52.This paper is dedicated to Birgit Grodal, whose strength and character we greatly admire. We are very grateful to Darrell Duffie, Steve Evans, Botond Koszegi, Roger Purves, Jacob Sagi, Chris Shannon, Bill Zame and an anonymous refereee for very helpful discussions and comments. The work of both authors was supported by Grant SES-9710424, and Andersons work was supported by Grant SES-0214164, from the National Science Foundation.     

Two-settlement Systems for Electricity Markets under Network Uncertainty and Market Power

We analyze welfare and distributional properties of a two-settlement system consisting of a spot market over a two-node network and a single energy forward contract. We formulate and analyze several models which simulate joint dispatch of energy and transmission resources coordinated by a system operator. The spot market is subject to network uncertainty, which we model as a random capacity derating of an important transmission line. Using a duopoly model, we show that even for small probabilities of congestion (derating), forward trading may be substantially reduced, and the market power mitigating effect of forward markets (as shown in Allaz and Vila 1993) may be nullified to a great extent. There is a spot transmission charge reflecting transportation costs from location of generation to a designated hub whose price is the underlying for the forward contract. This alleviates some of the incentive problems associated with the forward market in which spot-market trading is residual. We find that the reduction in forward trading is due to the segregation of the markets in the constrained state, and the absence of natural incentives for generators to commit to more aggressive behavior in the spot market (the strategic substitutes effect). In our analysis, we find that the standard assumption of no-arbitrage across forward and spot markets leads to very little contract coverage, even for the case with no congestion. We present an alternative view of the market where limited intertemporal arbitrage enables temporal price discrimination by competing duopolists. In this framework, we assume that all of the demand shows up in the forward market (or that the market is cleared against an accurate forecast of the demand), and the forward price is determined using a market clearing condition.     

就业体制改革不应忽视内部劳动力市场

本文吸收了西方劳动经济学和企业理论的新成果，论述了内部劳动力市场的基本原理，重新审视了我国以往的就业体制改革思路及其成本与收益．提出发展内部劳动力市场是当前深化我国就业体制改革亟待解决的一个重要问题，并阐述了若干具体的操作思路。     

生产劳动力的劳动时间的探讨

传统经济学的劳动力价值理论只有生产劳动力的生产费用(物化劳动),没有生产劳动力的劳动时间(活劳动)的耗费。劳动力的生产也有劳动时间的耗费。劳动力的自然再生产时间不形成劳动力的价值,劳动力的社会再生产时间、即学习劳动的时间形成劳动力的价值。劳动力价值包括两个部分:一是生产劳动力的物化劳动,如生活费用和学习费用等;二是生产劳动力的活劳动即学习劳动。     

我国农村劳动力转移面临的困难及对策

由于农村剩余劳动力数量庞大而素质较低，再加上观念认识不到位，组织管理工作滞后，就业环境不完善等，导致农村剩余劳动力转移困难，影响农民增加收入和农村小康社会建设。因此，必须采取多种措施，广辟就业渠道，优化就业环境，大力发展劳务中介组织，加强管理和协调，以使农村剩余劳动力有效有序地转移。     

从酸刺村看宁夏南部山区非农产业发展问题

过剩劳动力沉积于农业和农村是造成我国农村长期贫困的根源。宁夏南部山区的西海固由于历史和环境的原因，当地的贫困问题更为突出，发展非农产业来转移农村过剩的劳动力是解决这类地区贫困问题的根本途径。本文通过对宁夏南部西吉县酸刺村的调查分析来论述宁夏南部山区的非农产业发展问题。     

智力劳动的分配决定效应及模型

随着知识的积累与科技的进步 ,智力密集型劳动已经替代体力密集型劳动成为价值的最主要源泉。智力劳动的特征使得凝结在产品中的劳动含量与智力投资呈正相关 ,进而与其所形成的智力劳动力价值呈正向相关。因此 ,提高智力劳动力价值在分配决定机制中的权重 ,相对于现行以工龄为主体的工资决定体制而言 ,更能体现按“能”付酬原则 ,更能体现生产力的进步对分配的决定作用。以简单劳动力价值确定最低工资水平 ,然后依据每一阶次的智力劳动力价值差别确定工资水平差别 ,更能推动智力投资与劳动力资源的合理配置。以智力劳动力价值为基础的工资分配制度 ,可界定为一个基于贴现理论的微观静态分配模型。     

Tradeable permits,missing markets,and technology

This paper examines the effects of missing markets, heterogeneous pollutants, and the pollution technology of firms on the efficacy of transferable pollution permits. Under the assumption of perfect competition in all markets, we show that if firms can substitute among pollutants, then setting the optimal number of permits for only one pollutant will not, in general, lead to an efficient outcome. The degree of the inefficiency will depend on the information set available to the regulator and the substitutability among pollutants by firms. When establishing transferable pollution rights regulators should, therefore, consider the technology of firms. If firms discharge pollutants in the same fixed proportions, then the regulator need only set a market for one of the pollutants to ensure an efficient outcome. Where firms can substitute among pollutants, however, establishing a market for only one pollutant provides an incentive for firms to substitute to unregulated ones. This is an important policy issue as substitutability among pollutants within and across production processes may dampen the dynamic advantages of a tradeable permit policy.