农民工教育与职业的匹配及其工资效应——基于城市规模视角

农民工教育与职业的匹配状况对提高劳动力资源利用、增加劳动供给质量具有重要意义。本文使用中国流动人口动态监测调查2011～2016年微观数据,基于城市规模视角分析了农民工教育与职业的匹配状况对工资效应的差别。研究发现:人口规模越大的城市,农民工教育与职业的错配比例越高;中小城市农民工教育过度对工资的影响呈现工资嘉赏效应,大城市农民工教育过度对工资的影响以工资惩罚为主;而教育不足对农民工工资则普遍存在负向影响。农民工教育与职业不匹配对工资影响的理论机制表明,中小城市支持人力资本理论模型,而大城市和特大城市则支持分配理论模型。这意味着,农民工在中小城市表现出学历越高人力资本回报越高的特点;而在大城市,教育与职业适配则更为重要。因此,改善城市层面的教育-职业的适配性,让农民工在城市劳动力市场上自由流动和工作转换,进一步增强城市间劳动力资源的流动是相关政策调节的重点。     

Impacts of protected areas on local livelihoods: Evidence of giant panda biosphere reserves in Sichuan Province,China

Given the debates about whether Protected Areas (PAs) exacerbate local poverty or might contribute to poverty alleviation, there is a critical need for evidence to examine the impacts. In this study, we have conducted a household investigation of 560 rural households in 7 PAs of Sichuan province of China. We used matching method to value impacts of PAs on local livelihoods. The results showed that compared to the Average Treatment Effect, the results of traditional regression model exaggerate the negative impacts of the PAs. However, we should notice that the overall impact of PAs on local household wealth was still negative. Households inside the PAs had more Non-timber Forest Products gathering income and compensation, but fewer crop production income and forestry income. Better conservation policies need to be initiated to realize the harmonious and concurrent development of ecological objectives and livelihood objectives.     

A many-to-many ‘rural hospital theorem’

We show that the full version of the so-called ‘rural hospital theorem’ generalizes to many-to-many matching problems where agents on both sides of the problem have substitutable and weakly separable preferences. We reinforce our result by showing that when agents’ preferences satisfy substitutability, the domain of weakly separable preferences is also maximal for the rural hospital theorem to hold.     

The substitutes condition and the lattice structure of the set of stable allocations

In the many-to-one matching model with contracts, I show that there is no restriction on preferences weaker than substitutable preferences which guarantees that the set of stable allocations is a lattice. Thus, when contracts are not substitutes, removing agents from the economy may decrease the payoffs to existing agents on both sides of the market.     

Vacancy posting, job separation and unemployment fluctuations

What is the relative importance of hiring and separation in driving unemployment fluctuations? This paper presents a framework to decompose the moments of unemployment and study the respective contributions of vacancy posting, a measure of firms’ hiring efforts, and separation. Separation accounts for about 40% of unemployment's variance, compared to 60% for vacancy posting, and contributes to about 60% of unemployment steepness asymmetry, the fact that unemployment increases faster than it decreases. Further, while vacancy posting is, on average, the most important contributor of unemployment fluctuations, the opposite is true around business cycle turning points, when separation is responsible for most of unemployment movements.     

Efficient resource allocation under multi-unit demand

We study resource allocation with multi-unit demand, such as the allocation of courses to students. In contrast to the case of single-unit demand, no stable mechanism, not even the (student-proposing) deferred acceptance algorithm, achieves desirable properties: it is not strategy-proof and the resulting allocation is not even weakly efficient under submitted preferences. We characterize the priority structure of courses over students under which stability is consistent with strategy-proofness or efficiency. We show that stability is compatible with strategy-proofness or efficiency if and only if the priority structure is essentially homogeneous. This result suggests that efficient allocation under multi-unit demand is difficult and that the use of stable mechanisms may not deliver desirable outcomes.     

Equilibrium unemployment and retirement

We first propose some new empirical evidence on the fact that the labor market conditions matter for the retirement decision at the individual level: we investigate whether unemployed workers retire before employed workers, other things being equal. Our main objective in this paper is then to propose an equilibrium unemployment approach to retirement decisions that allows us to derive the positive and normative features of retirement decisions when search and matching frictions are considered. Two main conclusions emerge: the retirement decision of unemployed workers depends on the labor-market frictions whereas that of employed workers does not; the existence of search externalities makes the retirement age of unemployed workers intrinsically suboptimal. Considering Social Security policy issues, we show that the complete elimination of the implicit tax on continued activity is not necessarily welfare-optimizing in a second best world where the labor market equilibrium suffers from distortions.     

Firm-specific human capital in different market conditions: Evidence from the Japanese football league

This paper examined how and the extent to which obtaining skills to meet team specific human capital is important to improve football player’s performance by comparing the top league and the second league. Based on panel data of individual players during the 2012–2016 seasons of the Japan Professional Football League (J League), we found; (1) In the top-league, changing team reduced player’s performance and their performance improved as player’s tenure of the team and also tenure of J League increased. (2) returns from acquiring team specific skills on time of play in the game increase and then decrease as years have passed. (3) benefit from moving team depends on the timing of moving, and so rookie players can benefit from moving when team tenure reach 4 years or more. (4) In the second league, neither team tenure nor experience of the professional football player does not influence player’s performance.     

Revisiting the matching function

There is strong empirical evidence for Cobb–Douglas matching functions. We show in this paper that this widely found relation between matches on the one hand and unemployment and vacancies on the other hand can be the result of different underlying mechanisms. Obviously, it can be generated by assuming a Cobb–Douglas matching function. Less obvious, the same relationship results from a vacancy free-entry condition and idiosyncratic productivity shocks. A positive aggregate productivity shock leads to more vacancy posting, a shift of the idiosyncratic selection cutoff and thereby more hiring. We calibrate a model with both mechanisms to administrative German labor market data and show that idiosyncratic productivity for new contacts is an important driver of the elasticity of the job-finding rate with respect to the market tightness. Accounting for idiosyncratic productivity can explain the observed negative time trend in estimated matching efficiency and asymmetric business cycle responses to large aggregate shocks.     

A one-sided many-to-many matching problem

This study discusses a one-sided many-to-many matching model wherein agents may not be divided into two disjoint sets. Moreover, each agent is allowed to have multiple partnerships in our model. We restrict our attention to the case where the preference of each agent is single-peaked over: (i) the total number of partnerships with all other agents, and (ii) the number of partnerships that the agent has with each of the other agents. We represent a matching as a multigraph, and characterize a matching that is stable and constrained efficient. Finally, we show that any direct mechanism for selecting a stable and constrained efficient matching is not strategy-proof.