Testing the Validity of the Sibling Sex Ratio Instrument

We test the validity of the sibling sex ratio instrument suggested by Angrist and Evans using the methods proposed by Kitagawa and Huber and Mellace. The sex ratio of the first two siblings is arguably randomly assigned and influences the probability of having a third child, which makes it a candidate instrument for fertility when estimating the effect of fertility on female labor supply. However, identification hinges on the random assignment of the instrument, an instrumental exclusion restriction, and the monotonicity of fertility in the instrument. We find that the instrumental variable tests of Kitagawa and Huber and Mellace do not point to a violation of these assumptions in the Angrist and Evans data (which can, however, not be ruled out even asymptotically as the tests cannot detect all possible violations).     

IMMIGRATION,WAGES, AND COMPOSITIONAL AMENITIES

There is strong public opposition to increased immigration throughout Europe. Given the modest economic impacts of immigration estimated in most studies, the depth of anti‐immigrant sentiment is puzzling. Immigration, however, does not just affect wages and taxes. It also changes the composition of the local population, threatening the compositional amenities that natives derive from their neighborhoods, schools, and workplaces. In this paper we use a simple latent‐factor model, combined with data for 21 countries from the 2002 European Social Survey (ESS), to measure the relative importance of economic and compositional concerns in driving opinions about immigration policy. The ESS included a unique battery of questions on the labor market and social impacts of immigration, as well as on the desirability of increasing or reducing immigrant inflows. We find that compositional concerns are 2–5 times more important in explaining variation in individual attitudes toward immigration policy than concerns over wages and taxes. Likewise, most of the difference in opinion between more‐ and less‐educated respondents is attributable to heightened compositional concerns among people with lower education.     

基于博弈的“外包内做”型制造外包违规控制研究

在管理实践中发现,"外包内做"型外包模式已经成为了制造企业的重要生产方式之一,但生产质量问题却日渐突出。本文研究了"外包内做"型制造企业外包中承包方的违规行为控制问题。运用博弈分析方法,分三种情形:违规与罚款、罚款前提下违规与巡检、奖励与罚款前提下违规与巡检,分析了制造企业与劳务承包方关于制造质量的博弈,为解决制造企业生产阶段外包业务的质量控制问题提供了一种新的思路。研究结果表明:(1)除了以往研究者已证明的对违规罚款外,对履约奖励也一样可以有效地减少违规行为,但两者都有一定的适用条件,两者共同运用时,只要V-(1-a)(R+F+I)<0,承包方就会选择履约;(2)巡检仅能减少承包方的违规收益,但并不能改变承包方的违规行为,因此对控制违规意义不大;(3)提高违规被发现的概率,对减少劳务承包方的违规行为具有重要作用。根据研究结果,企业可采取罚款与奖励并用、提高违规被发现的概率、降低违规收益等方法达到对施工质量进行控制的目的。本文的研究将对采取"外包内做"型制造企业的质量管理提供一定的理论基础和实践指导。     

Firm Size and Employment Dynamics: Estimations of Labor Demand Elasticities Using a Fractional Panel Probit Model

This paper examines the comprehensive discussion on the relationship between job creation, or destruction and firm size. More specifically, the study will determine whether the argument about small‐ and medium‐sized enterprises (SMEs) showing higher employment dynamics is confirmed or not. As such, the following work applies elasticities from a standard labor demand model derived from the estimations of fractional probit models for panel data, as process recommended in Papke and Wooldridge [2008; Journal of Econometrics 145(1–2): 121–133]. Elasticities are a useful measure of employment dynamics, if it is assumed that SMEs act on the same markets. The elasticity results from German establishment data illustrate that firm size does matter for the increase or decrease of employment. SMEs with less than 10 workers exhibit a higher employment dynamic, compared with other entities, at each respective percentile in the distribution of the wage share. Additionally, the outcome of the analysis weakly confirms the hypothesis that smaller firms are more restricted to capital markets, compared with large entities. The results also illustrate that firm size only explains one aspect of job creation and destruction. As stated in the well‐known Hicks–Marshall rules for elasticities of factor demand, the results illustrate that the reaction of labor demand on economic changes increases with the share of labor. Firms with a high share of labor also have larger elasticities, compared with firms with a strong use of capital. Both effects, the size effect and the effect of the proportion of labor, would blend in reality, and therefore, possibly lead to controversial results for the relationship between firm size and employment dynamics. In addition, a model with a negative relationship among both variables is too simple to explain the behavior of firms.     

食品安全"监管困局"、 信号扭曲与制度安排

在既有研究提出的食品安全"监管困局"现象基础上,通过仿真建模及分析进一步解剖该困局的动态形成过程,构建食品市场中生产者、消费者和监管者构成的两期博弈模型,剖析食品安全"监管困局"的内在形成机理.研究发现:1)加大监管力度形成的违规揭露信息会影响到消费者的支付预期,当违规揭露水平超过消费者心理承受时会降低消费者的支付水平,进而影响食品行业平均收益,导致生产经营者的超额违规收益迅速增大,反过来又增强了生产经营者的违规动机,是为食品安全"监管困局"的动态形成过程;2)食品安全"监管困局"在于监管者与企业、监管者与消费者两种信息结构使监管力度的信号被扭曲所致,即政府监管力度对消费者形成信号扭曲,消费者无法通过市场价格实现质量信号分离,从而降低支付水平而影响行业平均收益.本文由此提出针对性的制度安排.     

期望效用视角下的风险对冲效率

与传统文献将风险下降比率作为风险对冲效率指标不同,本文引入期望效用理论来比较最小方差对冲策略、最小在险价值(VaR)对冲策略和最小条件在险价值(CVaR)对冲策略的对冲效率,从而将人们的风险态度同对冲策略选择联系起来,以实现不同风险态度的投资者选择不同风险对冲策略的目的。借用风险中性效用函数、二次效用函数和CARA效用函数,本文严格证明:在这三种对冲策略中,最小方差对冲策略过于保守,最小VaR对冲策略最为激进,风险厌恶程度大的投资者偏好最小方差对冲策略,风险中性投资者和风险厌恶程度小的投资者更偏好最小VaR对冲策略,最小CVaR对冲策略介于二者之间。     

On the radius of centrality in evolving communication networks

In this article, we investigate how the choice of the attenuation factor in an extended version of Katz centrality influences the centrality of the nodes in evolving communication networks. For given snapshots of a network, observed over a period of time, recently developed communicability indices aim to identify the best broadcasters and listeners (receivers) in the network. Here we explore the attenuation factor constraint, in relation to the spectral radius (the largest eigenvalue) of the network at any point in time and its computation in the case of large networks. We compare three different communicability measures: standard, exponential, and relaxed (where the spectral radius bound on the attenuation factor is relaxed and the adjacency matrix is normalised, in order to maintain the convergence of the measure). Furthermore, using a vitality-based measure of both standard and relaxed communicability indices, we look at the ways of establishing the most important individuals for broadcasting and receiving of messages related to community bridging roles. We compare those measures with the scores produced by an iterative version of the PageRank algorithm and illustrate our findings with three examples of real-life evolving networks: the MIT reality mining data set, consisting of daily communications between 106 individuals over the period of 1 year, a UK Twitter mentions network, constructed from the direct tweets between \(12.4\) k individuals during 1 week, and a subset of the Enron email data set.     

商品期货指数的编制研究及功能检验

在国际期货市场上,商品指数已经成为市场走势重要的风向标。而在国内市场上,商品指数的研究和开发还处于起步阶段。在国内为数不多的商品期货指数中,中科-格林商品期货指数(M-G Commodity futures index)是较为重要的一个。该指数在开发过程中充分借鉴了国际成熟商品指数的经验,同时也考虑了中国期货市场的自身发展特点,具有较强的适用性。本文以中科-格林商品指数为研究对象,阐述了商品期货指数的编制方法,并验证了指数的功能。     

Transitions in the Labour Market: Discouragement Effect and Individual Characteristics

The present work analyses the unemployment gender gap in Italy for the period 2004–11. We present a methodology for decomposing the natural rate of unemployment, thus defining it in terms of equilibrium labour market flows between the aggregate states of the labour market (Employment, Unemployment, Inactivity). In addition, we offer estimates of the determinants of the unemployment gender gap to pinpoint the relative role of individual characteristics and structural factors in determining this difference.     

基于失效情景的应急设施选址评估指标体系与模型

突发事件具有巨大的破坏性、不确定性,应急设施有可能失效,本文研究基于失效情景的应急设施选址评估指标体系与评估模型。首先基于定义的失效情景研究应急设施选址评估指标。构建全局性、可靠性、时效性、均衡性、经济性评估指标。可靠性作为重要评估指标有助于提高应急设施对需求区域的物资保障程度,保证系统的稳定性,采用多重覆盖率刻画。然后,设计具有不同侧重评估目标的一般情景评估指标体系、设施失效情景评估指标体系以及多区域情景评估指标体系。最后,由于应急设施选址评估具有多影响因素特征,涉及输入和输出多个指标的测度,选取处理多输入\多输出问题具有优势的评估方法—数据包络法,对应急设施选址的合理性进行评估。实例验证评估指标体系的实用性和有效性。     

Occupational and Locational Substitution: Measuring the Effect of Occupational and Regional Mobility

The paper analyses the effects of occupational and regional mobility on the matching rate using monthly panel data disaggregated at the regional and occupational level. The main contribution of the paper is to measure the effect of substitutability between vacancies in different occupations, and vacancies in different regions on the matching rate. The estimates indicate higher regional mobility in West Germany but higher occupational mobility in East Germany. The results show that if occupations were perfect substitutes, then the number of matches could increase by 5–9 per cent. Perfect regional mobility would increase matchings by 5–15 per cent. It is also shown that partial aggregation causes a downward bias in substitutability estimates.     

Is There Still a Wage Penalty for Being Overeducated But Well‐matched in Skills? A Panel Data Analysis of a Swiss Graduate Cohort

Using two periods' panel data from the Swiss Graduate Survey, this study examines the incidence, persistence and wage effects of overeducation. An alternative measure of overeducation that accounts for graduate heterogeneity in perceived skills mismatch is used. This analysis differs from previous panel data studies in that two estimation methods are applied to control for unobserved ability. Results indicate that graduates who are overeducated and mismatched in skills are the most penalized in terms of earnings. This evidence is still valid when unobserved ability is accounted for, whereas the pay penalty is no more significant for graduates who are overeducated but matched in skills. This result is robust to different definitions of perceived skills mismatch and is consistent with the notion that apparent overeducation reflects a lack of unobserved attributes, such as ability.     

Summarizing Risk Using Risk Measures and Risk Indices

Our society is fascinated with risk in many different areas and disciplines. One of the main ways to describe and communicate the level of risk is through risk indices, which summarize risk using numbers or categories such as words, letters, or colors. These indices are used to communicate risks to the public, understand how risk is changing over time, compare among different risks, and support decision making. Given the different methods to construct risk indices, including flawed methods such as risk matrices, this article develops specific steps that analysts can follow to create a risk index. This article emphasizes the importance of describing risk with a probability distribution, developing a numerical risk measure that summarizes the probability distribution, and finally translating the risk measure to an index. Measuring the risk is the most difficult part and requires the analyst to summarize a probability distribution into one or possibly a few numbers. The risk measure can then be transformed to a numerical or categorical index. I apply the method outlined in this article to construct a risk index that compares the risk of fatalities in aviation and highway transportation.     

心理契约研究述评

从心理契约的概念界定、结构维度、形成过程、违背及后果4个方面对心理契约的研究现状进行了逐一梳理,指出了目前已取得的成果,分析了存在的问题。认为心理契约未来研究的发展趋势是:研究范围不断扩展,呈现出多层面立体交叉的格局;将在理论与实证研究互动的基础上,进一步廓清心理契约理论框架;在心理契约双向视角的实证研究中,开发双向责任的有效测量工具将是未来值得期待的一个研究方向;心理契约的问题将成为一个多学科交叉渗透的研究领域。     

FAMILY VALUES AND THE REGULATION OF LABOR

To be efficient, flexible labor markets require geographically mobile workers. Otherwise firms can take advantage of workers' immobility and extract rents at their expense. In cultures with strong family ties, moving away from home is costly. Thus, to limit the rents of firms and to avoid moving, individuals with strong family ties rationally choose regulated labor markets, even though regulation generates higher unemployment and lower incomes. Empirically, we find that individuals who inherit stronger family ties are less mobile, have lower wages and higher unemployment, and support more stringent labor market regulations. We find a positive association between labor market rigidities at the beginning of the 21st century and family values prevailing before World War II, and between family structures in the Middle Ages and current desire for labor market regulation. Both results suggest that labor market regulations have deep cultural roots.     

COMPETITION AND GENDER PREJUDICE: ARE DISCRIMINATORY EMPLOYERS DOOMED TO FAIL?

According to Becker's famous theory on discrimination (Gary Becker, 1957 , The Economics of Discrimination, University of Chicago Press), entrepreneurs with a strong prejudice against female workers forgo profits by submitting to their tastes. In a competitive market their firms lack efficiency and are therefore forced to leave. We present new empirical evidence for this prediction by studying the survival of start‐up firms in longitudinal matched employer–employee data. We find that firms with strong preferences for discrimination approximated by a low share of female employees relative to the industry average have significantly shorter survival rates. This is especially relevant for firms starting out with female shares in the lower tail of the distribution. Competition at the industry level additionally reduces firm survival and accelerates the rate at which prejudiced firms are weeded out. We also find evidence for employer learning as highly discriminatory start‐up firms that manage to survive submit to market powers and increase their female workforce over time.     

The Implications of Temporary Jobs on the Distribution of Wages in Italy: An Unconditional IVQTE Approach

Using Italian data, this paper investigates the wage implications of temporary jobs across the whole pay profile using unconditional quantile regression (UQR) models. Results clearly indicate that the wage penalty associated to temporary jobs is significantly larger at the bottom of wage profile and is almost absent for high‐wage jobs. This is in line with the sticky floors hypothesis, supporting the idea that the wage gap for temporary employees depends on their position in the wage distribution for low‐paid jobs. To recover a causal interpretation, I employ an instrumental variable (IV) strategy. I adopt the unconditional instrumental variable quantile treatment effects (IVQTE) estimator proposed by Frolich and Melly, which corrects for endogenous selection in temporary contracts. The IVQTE estimates yield similar results to standard UQR, even if the wage penalty is larger in size at the bottom of the wage distribution and disappears at the top quantiles. This evidence highlights that policies aimed at increasing flexibility may reinforce the two‐tier nature of the Italian labour market and the relative wage inequality.     

New lower bounds for the second variable Zagreb index

The aim of this paper is to obtain new sharp inequalities for a large family of topological indices, including the second variable Zagreb index \(M_2^{\alpha }\), and to characterize the set of extremal graphs with respect to them. Our main results provide lower bounds on this family of topological indices involving just the minimum and the maximum degree of the graph. These inequalities are new even for the Randi?, the second Zagreb and the modified Zagreb indices.     

IMMIGRATION,JOBS, AND EMPLOYMENT PROTECTION: EVIDENCE FROM EUROPE BEFORE AND DURING THE GREAT RECESSION

In this paper we analyze the impact of immigrants on the type and quantity of native jobs. We use data on 15 Western European countries during the 1996–2010 period. We find that immigrants, by taking manual‐routine type of occupations pushed natives towards more “complex” (abstract and communication) jobs. This job upgrade was associated to a 0.7% increase in native wages for a doubling of the immigrants' share. These results are robust to the use of an IV strategy based on past settlement of immigrants across European countries. The job upgrade slowed but did not come to a halt during the Great Recession. We also document the labor market flows behind it: the complexity of jobs offered to new native hires was higher relative to the complexity of lost jobs. Finally, we find evidence that such reallocation was larger in countries with more flexible labor laws.     

The Effects of Personality Traits on Wages: A Matching Approach

I use the National Longitudinal Survey of Youth 1979 to estimate the effects of adolescent measurements of self‐esteem and locus of control on adult wages using propensity score matching. An adolescent possessing high self‐esteem will experience between 8.5 and 9.2 per cent higher wages as an adult. This result is statistically significant and robust to the addition of cognitive skill and family background characteristics. When cognitive skill and family background characteristics are controlled for, locus of control as an adolescent is insignificant in explaining adult wages. This result is contrary to findings in the literature.