A Test of Two Skew Models to Explain Cooperative Breeding

Synopsis Two competing models, reproductive skew and skew selection, have been constructed to explain the evolution of cooperation among unrelated breeders. Reproductive skew is a trade-off model that assumes breeding occurs under scarce resource conditions. One breeder gains units of fecundity at the expense of other breeders during aggressive, altruistic or tug-of-war transactions. After joining, the distribution of fecundity among breeders shifts from symmetrical to asymmetrical. In contrast, skew selection is a surplus model that assumes breeding occurs during a springtime glut. Skew selection assumes that fecundity among breeders is initially asymmetrical and that joining reduces the asymmetry of fecundity. This paper reports findings from a breeding experiment on the fire ant, Solenopsis invicta, which supported skew selection rather than reproductive skew. Joining was a win-win strategy for alpha and beta breeders; beta breeders gained within-group survival benefits; alpha breeders gained between-group survival benefits. In summary, skew selection extends Darwin’s theory of natural selection by revealing the self-interested core of cooperative breeding.      

Dissertation abstract: “Essays in applied economics on the intervention of a third player in agency relationships”

Agency theory has established that appropriate incentives can reconcile the diverging interests of the principal and the agent. Focusing on three applications, this dissertation evaluates the empirical relevance of these results when a third party interacts with the primary contract. The analyses provided rely on either laboratory or natural experiments. First, corruption is analyzed as a two-contract situation: a delegation contract between a Principal and an Agent and a corruption pact concluded between this Agent and a third player, called Briber. A survey of the recent microeconomic literature on corruption first highlights how corruption behavior results from the properties of those two agreements. We thereafter show that the Agent faces a conflict in reciprocities due to those two conflicting agreements. The resulting delegation effect, supported by observed behavior in our three-player experimental game, could account for the deterrence effect of wages on corruption. Second, health care is governed by contradictory objectives: patients are mainly concerned with the health provided, whereas containing health care costs is the primary goal of health care administrators. We provide further insights into the ability of incentives to balance these two competing objectives. In this matter, our theoretical and econometric analysis evaluates how a new mixed compensation scheme, introduced in Quebec in 1999 as an alternative to fee-for-services, has affected physicians’ practice patterns. Free switching is shown to be an essential feature of the reform, since it implements screening between physicians. Finally, the demand for underground work departs from the traditional Beckerian approach to illegal behavior, due to the dependence of benefits from illegality on competitors’ behavior. We set up a theoretical model in which the demand for underground work from all producers competing on the same output market is analyzed simultaneously. We first show that competition drastically undermines the individual benefits of tax evasion. At equilibrium, each firm nonetheless chooses evasion with a positive probability, strictly lower than one. This Bertrand curse could then account for the “tax evasion puzzle” i.e. the overprediction of evasion in models that ignore market interactions. We thereafter show that allowing firms to denounce competitors’ evasion is not likely to solve this curse—by providing a credible threat against price cuts, it fosters illegal work. Empirical evidence from a laboratory experiment confirms these predictions. Without denunciation, experimental firms often choose evasion whereas evasion benefits are canceled out by competition. When introduced, denunciation is rarely used by firms, but the threat makes evasion profitable. JEL Classification K42, I18, D21, C25, C91     

Constitutional coordination in unstable party systems: the Brazilian constitution of 1988

Constitutional assemblies are a common feature of many democratic transitions. However, the goal of coordinating constitutional choice would seem nearly impossible when assemblies are comprised of highly fragmented and volatile political parties. Building on Knight’s bargaining model, this article argues that the main challenge to coordination in unstable party systems is the procedural disequilibrium that results from incomplete information over breakdown payoffs. The likelihood of compromise in such circumstances is a function of the ideologies that frame constitutional choice and inform coalition-building. Thus, unstable party systems are not chaotic, although they may be deeply conflict-laden. These issues are illustrated empirically via the Brazilian Constitution of 1988, which demonstrates the possibilities for a stable constitutional order emerging from a fragmented and volatile party system.

Candidate stability and nonbinary social choice

Summary. The requirement that a voting procedure be immune to the strategic withdrawal of a candidate for election can be formalized in different ways. Dutta, Jackson, and Le Breton (Econometrica, 2001) have recently shown that two formalizations of this candidate stability property are incompatible with some other desirable properties of voting procedures. This article shows that Grether and Plott's nonbinary generalization of Arrow's Theorem can be used to provide simple proofs of two of their impossibility theorems. Received: August 15, 2001; revised version: March 11, 2002 RID="*" ID="*" Parts of this article were previously circulated in somewhat different form in a working paper with the same title by the second author. We are grateful to Michel Le Breton and an anonymous referee for their comments. Correspondence to:J.A. Weymark     

Labor income and risky investments: can part-time farmers compete?

In the developed countries, a majority of farm households receive at least as much income from nonfarm sources as from the farm. Such part-time farms have survived inspite of lower returns than full-time farms. This paper considers when lower returns to part-time farming could be compensated by risk-reduction due to diversification of income sources. The paper uses a dynamic portfolio choice model with labor income. The model and results could be applied in other contexts as well.     

The Determinants of Sticky Prices and Sticky Plans: Evidence from German Business Survey Data

So far, there is no consensus on the price adjustment determinants in the empirical literature. Analyzing a novel firm‐level business survey data set, we provide new insights on the price setting behavior of German retailers during a low inflation period. Relating the probability of both price and pricing plan adjustment to time‐ and state‐dependent variables, we find that state‐dependence is important; the macroeconomic environment as well as the firm‐specific condition significantly determines the timing of both actual price changes and pricing plan adjustments. Moreover, input cost changes are important determinants of price setting. Finally, price increases respond more strongly to cost shocks compared to price decreases.     

心理所有权的非均衡发展及其影响效应研究

本文在组织心理所有权的基础上提出工作心理所有权,研究两者分别对组织行为的影响,以及两者之间的非均衡发展对组织行为的影响。经过理论分析和实证检验,本文认为,组织心理所有权和工作心理所有权都可以解释组织承诺、工作满意度、OCB和角色外行为等,但工作心理所有权的解释能力更强。心理所有权在组织和工作层面存在显著差异,呈现非均衡发展的现象。当心理所有权的这种非均衡发展超过一定限度之后,较强的工作心理所有权和较低的组织心理所有权降低了组织承诺和工作满意度,并对OCB和角色外行为产生不利影响。本文在这些研究的基础上,进一步解释了心理所有权"阴暗面"的产生机制,分析了可能产生的员工消极行为并提出了相应的对策建议。     

支付制度、医生的行为与药物经济学的应用

制度影响人们的行为选择,引发不同的效率结果。在医疗卫生市场中,不同的支付制度加上一些其他经济因素,使得追求收益最大化的医生具有不同的目标收益函数和行为选择。这些行为选择对社会而言可能具有效率,也可能无效率。通过比较不同支付制度下医生的行为选择及其是否符合效率准则,我们能够发现对药物经济学应用有利的一些制度因素。     

Optimal savings with taxable and tax-deferred accounts

We solve and estimate a life-cycle model with earnings risk and liquidity constraints in the presence of tax-deferred retirement accounts (TDAs). We explicitly consider two very different types of households (with TDAs): direct and indirect stockholders. The latter hold stocks only through TDAs and, consistent with the data, save considerably less than the former, who hold stocks both inside and outside these accounts. We find that TDAs promote higher wealth accumulation but only marginally higher net savings. Consumption increases mostly during retirement, as desired, but the effect is largest for those households with higher savings rates already.