Equilibrium Wage Dispersion with Worker and Employer Heterogeneity

We construct and estimate an equilibrium search model with on–the–job–search. Firms make take–it–or–leave–it wage offers to workers conditional on their characteristics and they can respond to the outside job offers received by their employees. Unobserved worker productive heterogeneity is introduced in the form of cross–worker differences in a “competence” parameter. On the other side of the market, firms also are heterogeneous with respect to their marginal productivity of labor. The model delivers a theory of steady–state wage dispersion driven by heterogenous worker abilities and firm productivities, as well as by matching frictions. The structural model is estimated using matched employer and employee French panel data. The exogenous distributions of worker and firm heterogeneity components are nonparametrically estimated. We use this structural estimation to provide a decomposition of cross–employee wage variance. We find that the share of the cross–sectional wage variance that is explained by person effects varies across skill groups. Specifically, this share lies close to 40% for high–skilled white collars, and quickly decreases to 0% as the observed skill level decreases. The contribution of market imperfections to wage dispersion is typically around 50%.     

Knocking on Academia's Doors: An Inquiry into the Early Careers of Doctors in Life Sciences

The early careers of French doctors in life sciences are characterized by the importance of temporary jobs. While most young Ph.D. researchers wish to obtain a job in the French academic sector (which grants them, among other things, lifetime employment), few of them manage to achieve this objective immediately after completing their Ph.D. A majority of young doctors have to wait for a period of time before they find stable employment in the academic sector. In the meantime, they usually find temporary research jobs. Two main types of short–term jobs can be distinguished: fixed–term research contracts (in most cases in a French public laboratory) and post–doctoral positions (temporary research jobs in a foreign country). The aim of this paper is to determine whether these different types of temporary jobs have different consequences on the careers of Ph.D. researchers. We first discuss from a theoretical perspective the impact of choosing ‘post–doc’ research rather than a job on a fixed–term contract. Then, after dealing with selection biases that affect the access to these temporary jobs, we will use survival data analysis to estimate the impact of both types of temporary positions on the probability of entering the academic sector. The analysis is based on a database on the early careers of 800 young French doctors in life sciences. The main results include the following findings: the probability of a Ph.D. researcher finding stable employment is higher if he has held a post–doc position than if he has held a fixed–term contract. This result holds for both the private and public sectors. However, careers in the private sector are also affected by long–term choices, such as the decision to undertake Ph.D. research in partnership with a firm.     

Latent Separability: Grouping Goods without Weak Separability

This paper develops a new concept of separability with overlapping groups—latent separability. This is shown to provide a useful empirical and theoretical framework for investigating the grouping of goods and prices. It is a generalization of weak separability in which goods are allowed to enter more than one group and where the composition of groups is identified by the choice of group specific exclusive goods. Latent separability is shown to be equivalent to weak separability in latent rather than purchased goods and provides a relationship between separability and household production theory. For the popular class of linear, almost ideal and translog demand models and their generalizations, we provide a method for choosing the number of homothetic separable groups. A detailed method for exploring the composition of the separable groups is also presented. These methods are applied to a long time series of British individual household data on the consumption of twenty two nondurable and service goods.     

Integrating Knowledge through Information Trading: Examining the Relationship between Boundary Spanning Communication and Individual Performance*

With the global penetration of Internet technologies, individuals may now cross organizational boundaries to communicate efficiently with others regardless of time and space. Thus, when looking for help in solving work tasks, knowledge workers may just as easily contact individuals in rival firms across the globe as a coworker sitting at the next desk. As a result, management faces questions such as (1) How should firms manage employees' knowledge‐sourcing activities when they span both intra‐organizational and extra‐organizational boundaries, and (2) What is the relationship between different knowledge‐sourcing activities and individual performance? Grounded in the knowledge‐based view of the firm, we investigate these questions using data from Europe's largest information technology (IT) services and management consulting company. Our results provide evidence that organizations should support boundary spanning and knowledge sourcing from both internal and external sources. Results suggest (1) a positive relationship between boundary spanning communication and creativity and general performance, and (2) a negative relationship between a reliance on colocated coworkers as knowledge sources and creativity.     

State estimation for aoristic models

Aoristic data can be described by a marked point process in time in which the points cannot be observed directly but are known to lie in observable intervals, the marks. We consider Bayesian state estimation for the latent points when the marks are modeled in terms of an alternating renewal process in equilibrium and the prior is a Markov point process. We derive the posterior distribution, estimate its parameters and present some examples that illustrate the influence of the prior distribution. The model is then used to estimate times of occurrence of interval censored crimes.     

A Mixed-Methods Approach to Refining and Measuring the Construct of Positive Risk-Taking in Adolescence

Adolescence is a peak period for risk-taking, but research has largely overlooked positive manifestations of adolescent risk-taking due to ambiguity regarding operationalization and measurement of positive risk-taking. We address this limitation using a mixed-methods approach. We elicited free responses from contemporary college students (N = 74, M_age = 20.1 years) describing a time they took a risk. Qualitative analysis informed the construction of a self-report positive risk-taking scale, which was administered to a population-based sample of adolescents (N = 1,249, M_age = 16 years) for quantitative validation and examination of associations with normative and impulsive personality. Sensation seeking predicted negative and positive risk-taking, whereas extraversion and openness were predominantly related to positive risk-taking. Results provide promising evidence for a valid measure of adolescents' engagement in positive risks.     

Sampling refugee groups: The example of Syrians in Turkey

Quantitative surveys among refugees not only advance our scientific understanding of forced migration, but they also provide political and civil society actors with the information they need to take measures to improve their protection and living conditions. These actors often need to acquire such information within a short period of time. However, the methods to access and survey this group to gain valid findings are subject to scientific debates. Based on a survey among Syrian refugees in Turkey, this article demonstrates a study design that generated valid knowledge about this population within a limited amount of time and resources. As a unique feature of the article, we compare our sample with four other sources of information to scrutinize how well it resembles the target population. As we can show, although point estimations differ to some extent, the internal distributions of sample characteristics are comparable across sources confirming the success of our sampling method.