Alternative theories of wage dispersion

We analyze labor market models where the law of one price fails—i.e., models with equilibrium wage dispersion. We begin considering ex ante heterogeneous workers, but highlight a problem with this approach: If search is costly the market shuts down. We then assume homogeneous workers but ex post heterogeneous matches. This model is robust to search costs, and delivers equilibrium wage dispersion. However, we prove that the law of two prices holds: Equilibrium implies at most two wages. We explore other models, including one combining ex ante and ex post heterogeneity which is robust and delivers more realistic wage dispersion.     

Training, search and wage dispersion

This paper combines on-the-job search and human capital theory to study the coexistence of firm-funded general training and frequent job turnovers. Although ex ante identical, firms differ in their training decisions. The model generates correlations between various firm characteristics that are consistent with the data. Wage dispersion exists among ex ante identical workers because workers of the same productivity are paid differently across firms, and because workers differ in their productivity ex post. Endogenous training breaks the perfect correlation between work experience and human capital, which yields new insights on wage dispersion and wage dynamics.     

从事前效率问题到事后效率问题——不完全合同理论的几类经典模型比较

通过对不完全合同经典理论模型的组成要素的梳理和分类,本文首次将不完全合同理论的模型分为四种类型:行动事前不可缔约而事后可缔约的事前效率问题模型,行动事前和事后都不可缔约的事前和事后效率问题模型,事前部分可缔约的事前和事后效率问题模型,收益事后不可证实的事前和事后效率问题模型。这些不同的理论被纳入一个统一的框架中进行表述。传统的产权理论具有一些缺陷,而事后不可缔约的模型更适合研究权威、授权、科层等问题。相对于关于投资激励的事前效率问题,事后效率问题的来源要多得多。对事前与事后缔约性问题的探讨以及对事后效率问题的研究是丰富不完全合同理论发展的动力。     

Unemployment duration and economic incentives—a quasi random-assignment approach

We investigate how economic incentives and spell duration affect hazard rates out of insured unemployment. We take into account that insured unemployment not always ends in employment, but also in disability, training programs, or benefit sanctions. Our empirical basis is Norwegian register data containing variation in economic incentives and spell duration similar to that of random-assignment experiments. We find that the employment and benefit-sanction hazards are negatively affected by the unemployment insurance replacement ratio, but that the effects vary considerably among individuals. There is negative duration dependence in the employment hazard and positive duration dependence in the disability hazard.     

Complexity and Renegotiation: A Foundation for Incomplete Contracts

The paper considers a hold-up model where only one of n future trading opportunities will prove to be efficient, and where ex post renegotiation of the ex ante contract cannot be prevented. As the environment becomes more complex ( n →∞), the outcome under any message-contingent long-term contract converges to that of the "incomplete contracting" model where trade is contractible ex post , but not ex ante . When trades are costly to describe, both ex ante and ex post , the incomplete contracting result is extended to a broader class of environments.     

EX POST VERSUS EX ANTE MEASURES OF THE USER COST OF CAPITAL

Should we use ex post or ex ante measures of user costs to calculate the contribution of capital in a growth accounting exercise? The answer, based on a simple model of temporary equilibrium, is that ex post is better in theory. In practice researchers usually calculate ex post user costs by assuming that the rate of return is equalized across assets. But this is only true if expectations are correct. In general, the ex post rate of return differs between assets, even though ex ante it is the same. I propose a hybrid method. The index of capital services is estimated using ex ante weights; the contribution of capital is the growth of this index multiplied by the ex post income share of capital. I show that this method is theoretically correct if the production function is CES. I compare the ex post, ex ante and hybrid methods using data for 31 U.K. industries from 1970 to 2000.     

Unequal uncertainties and uncertain inequalities: an axiomatic approach

In this paper, we provide an axiomatic characterization of social welfare functions for uncertain incomes. Our most general result is that a small number of reasonable assumptions regarding welfare orderings under uncertainty rule out pure ex ante as well as pure ex post evaluations. Any social welfare function that satisfies these axioms should lie strictly between the ex ante and the ex post evaluations of income distributions. We also provide an axiomatic characterization of the weighted average of the minimum and the maximum of ex post and ex ante evaluations.     

On competitive balance in the group stage of the UEFA Champions League*

This article examines competitive balance in the group stage of the UEFA Champions League over the last two decades (1999/2000–2017/2018). Competitive balance is considered both before and after a competition. Have the groups been designed in such a way as to ensure similar levels of competitive balance ex ante? Have the demonstrated strengths (ex post competitive balance) of the different groups been similar over each season? What is the relationship between the competitive balance in the designed groups and that achieved in the same groups after the competition? Are the performance achieved in terms of ex post competitive balance similar to ex ante competitive balance levels? We found that, despite expectations, the groups' ex ante competitive balance was not homogeneous. Although ex ante competitive balance serves as a good predictor, on average, of ex post competitive balance, we observed significant differences at the levels of group and seasons. Therefore, it is possible to improve the design mechanism of the groups that make up the group stage of the champions so that they are composed homogeneously in terms of ex ante competitive balance.     

Use it or lose it

We examine the optimality of budget policies imposed by a funding authority on a bureaucrat who operates under a fixed budget. In particular, we study a “use‐it‐or‐lose‐it” (UILI) policy under which the bureaucrat has to return any unspent budget without being able to “roll over” any part to the next period. Instead of returning the unspent budget, the bureaucrat can go on a spending spree and engage in policy drift, which is inversely related to his motivation. The bureaucrat's motivation represents how well matched he is with the bureaucracy's mission. We show that a UILI policy is complementary to motivation as it has stronger ex ante positive incentive effects on more motivated bureaucrats. Such ex ante positive effects can overcome the ex post inefficiency of the policy and make a UILI policy optimal when the bureaucrat is well matched with the bureaucracy's mission or when its budget is large.     

Smoothing sudden stops

Emerging economies are often exposed to sudden shortages of international financial resources. Yet domestic agents do not seem to take preventive measures against these sudden stops. We highlight the central role played by the limited development of ex ante (insurance) and ex post (spot) domestic financial markets in generating this collective undervaluation of international resources. We study several policies to counteract the external underinsurance. We do this by solving for the optimal mechanism given the constraints imposed by limited financial development, and then considering the main financial policies—in terms of the model and practical relevance—that implement this solution.     

Location decisions of a polluting firm and the time consistency of environmental policy

This paper considers location decisions of a monopolist, who faces a tax on its emissions in the home country, under ex post that is, time consistent, and ex ante, that is precommitment, environmental policies. We show that the monopolist will relocate more often under ex post optimal emission taxes. A government which cannot commit to an ex ante emission tax and sets its tax ex post after abatement effort has been chosen, is unable to affect the monopolist’s location decision, because it cannot commit to strategically reduce its tax level in the first stage. Domestic welfare is often higher under ex post emission taxes whenever the monopolist relocates under both policy regimes. Otherwise, welfare is higher under government commitment to an ex ante emission tax level. Thus, government commitment to a policy is not always welfare improving.     

The public management of risk: Separating ex ante and ex post monitors

When a firm undertakes risky activities, the conflict between social and private incentives to implement safety care requires public intervention which can take the form of both monetary incentives and also ex ante or ex post monitoring, i.e., before or after an accident occurs. We delineate the optimal scope of monitoring depending on whether public monitors are benevolent or corruptible. We show that separating the ex ante and the ex post monitors increases the likelihood of ex post investigation, helps prevent capture and improves welfare.     

Increasing consumer well-being: risk as potential driver of happiness

This article investigates the relation between risk and individual well-being. We propose a theoretical model of happiness that makes a distinction between ex ante evaluations of happiness and ex post assessments. The main assumptions of the model are tested through three studies based on anchoring vignettes. We show that, even if, ex ante, consumers fear high risk and do not associate it to a high level of happiness, their ex post evaluation of well-being is generally higher when identical consequences result from a high-risk situation than from a low-risk situation. Control over risk-taking reinforces the gap between ex ante and ex post measures of happiness. Thus, our article provides empirical evidence about a positive relation between risk and individual well-being, suggesting that risky experiences have the potential to increase consumer well-being.     

The role of ex ante and ex post decisions in the valuation of life

This paper examines the use of ex ante and ex post criteria in the evaluation of projects involving the risk of death. One issue concerns the appropriate welfare function, and it is argued that this should reflect both ex post and ex ante considerations, but not in the form of restrictions on the welfare function. The second issue concerns the form of compensation. The argument in favour of ex post compensation as a means of reducing the cost of risk-bearing needs to be modified when risks involve more than a single dimension as they do in projects involving the risk of death.     

Do Lower Caseloads Improve the Performance of Public Employment Services? New Evidence from German Employment Offices

The caseworker‐to‐clients ratio is an important, but understudied, policy parameter that affects both the quality and cost of public employment services that help job seekers find employment. We exploit a large‐scale pilot by Germany's employment agency, which hired 490 additional caseworkers in 14 of its 779 offices. We find that lowering caseloads caused a decrease in the rate and duration of local unemployment as well as a higher re‐employment rate. Disentangling the mechanisms that contributed to this improvement, we find that offices with lowered caseloads increased monitoring and imposed more sanctions but also intensified search efforts and registered additional vacancies.     

Island matching

A plausible micro foundation for the matching function, postulated in models of equilibrium unemployment, is proposed. The flow of matches formed is an increasing and concave function of the number of jobs and workers to be matched holding the other constant, but exhibits increasing to scale. Nevertheless, the function is consistent with the observed Beveridge curve and the log linear relationship between the job finding rate and the vacancy-unemployment ratio. Although a market equilibrium in which wages are determined by ex post auctions is not constrained efficient, a modified auction exists that decentralizes the solution to the social planner's problem.     

Bargaining In International Trade Under Exchange-Rate Uncertainty

This paper examines the implications of various contracting alternatives between exporting and importing firms on the volume of international transactions. the contracts that we study are determined in a bargaining situation under exchange-rate uncertainty. First we look at contracts which entail an ex ante commitment on price and quantity of exports without the possibility of renegotiation ex post. Second, spot contracts, i.e., the price and the quantity of exports are negotiated after the exchange the rate is known. A third type of contracts consists of ex ante commitment and ex post renegotiation.     

Asymmetric information, optimal money growth targets, and fed secrecy in a monetary policy game

This paper analyzes the impact on inflation of requiring the monetary authority to announce money supply targets and punishing it for deviations from same. Two regimes are considered. In one, called the ex ante regime, the target is announced prior to the authority's obtaining information concerning relevant economic shocks. In the other, called the ex post regime, the announcement is made after the authority obtains relevant information and thus provides the public with data concerning the authority's private information. It is shown that the ex ante regime may dominate the ex post regime. This follows because an ex post regime may yield a higher mean inflation rate as the monetary authority attempts to exploit the relationship between its announcement and expected inflation.     

Ordinary Shares and Managers

We argue that ordinary shares undermine any inherent commitment of its holders to resist renegotiating away ex post inefficiencies. Yet, in a dynamic adverse selection problem, such ex post inefficiencies are optimal from an ex ante point of view. We show that shareholders may use a manager in combination with a golden parachute (managerial severance payments) as a commitment device not to renegotiate ex post.     

On the efficiency of ex ante and ex post pricing institutions

Summary This paper compares the performance of three pricing institutions in a decentralized matching model in which random matching occurs. In the first, sellers make public ex ante commitments to trade at pre-specified prices before matching occurs. In the second, the buyer and seller engage in an alternating offer bargaining game once a match has occurred. In the final pricing institution, one party is chosen at random to make a take it or leave it price offer. The steady state equilibrium with ex ante pricing pareto dominates the steady state equilibrium with ex post take it or leave it offers, which in turn pareto dominates the steady state equilibrium with alternating offers. As the discount factor goes to one, the equilibrium with ex ante pricing generates participation rates that tend toward the pareto efficient level. The ex post pricing institutions generate participation rates that are bounded away from efficient levels. The surplus loss associated with switching from ex ante pricing to take it or leave it offers is small when the discount factor is close to one. Contrary to many models of decentralized trade, ex post pricing institutions encourage too much search by buyers.The financial support of the Social Sciences and Humanities Research Council of Canada is gratefully acknowledged. The research for this paper was completed while the author was visiting the University of California at San Diego. The author thanks Douglas Gale for comments.