Core concepts in economies where information is almost complete

Summary. The paper analyzes the properties of cores with differential information, as economies converge to complete information. Two core concepts are investigated: the private core, in which agents' net trades are measurable with respect to agents' private information, and the incentive compatible core, in which coalitions of agents are restricted to incentive compatible allocations. Received: March 15, 2000; revised version: August 24, 2000     

Contests where there is variation in the marginal productivity of effort

Summary. We provide a characterization of participants' behavior in a contest or tournament where the marginal productivity of effort varies across contestants and individual productivity is private information. We then consider the optimal design of such a contest. We first analyze contestant behavior for the usual type of contest, where the highest output wins. Abilities need not be independently distributed. We demonstrate that there is a unique symmetric equilibrium output function, that output is increasing in ability, and that marginal effort is increasing in ability, while effort decreases when the cost of effort increases. Next we consider the case where the highest output need not win, with independently distributed abilities. We analyze the contest designer's decisions in choosing contest rules optimal from her perspective. We show that the output produced, probability of winning, and contest designer's expected revenue are generally increasing in contestants' ability. We examine the relationship between the marginal cost of producing output and marginal utility per dollar of the net award for winning. Received: July 30, 1998; revised version: August 7, 2000     

Home is where the hurt is: an econometric analysis of injuries caused by spousal assault

Using data on injuries presenting at the emergency departments of participating hospitals in the Australian state of Queensland we examine the nature of injuries resulting from spousal assault and compare them to injuries from nonspousal assault and accidental injuries. We ask: who are the persons most vulnerable to spousal assault?, Are spousal assault injuries more (or less) severe than injuries from nonspousal assault and accidental injuries? Do the recorded figures for assault injuries on women understate the true number of assault injuries, and if so, by how much?

‘But for my bonny Kate, she must with me. I will be master of what is mine own. She is my goods, my chattels’ (Taming of the Shrew).     

The economics of posted prices in a concentrated market where demand is uncertain

This paper analyses the theory of the optimal output decision for a firm whose policy is to post a non-negotiable price for a good or service in a concentrated market where the demand facing the firm is determined, in part, by a random variable. The theoretical findings are the opposite of those in competitive markets; Proposition 1 states that the optimal output of a risk-averse firm is expected to be larger than that of a risk-neutral firm if the expected payoff of its marginal profit is less than or equal to 1. Proposition 2 states that the optimal output of a risk-seeking firm is expected to be smaller than that of a risk-neutral firm if the expected payoff of its marginal profit is greater than 1.     

Local public expenditure in Sweden a model where the median voter is not necessarily decisive

This paper deals with local public expenditures, and the analysis is based on cross-section data for the Swedish municipalities. Two models are estimated; one is the basic median voter model where the decisive voter is assumed to be the voter with median income, while the other is a more general statistical alternative. The statistical alternative nests the basic median voter model as a special case, which makes it easy to test the null hypothesis that the basic median voter model is the correct model, given that the alternative is the true general structure. Although our results indicate a rejection of the null hypothesis, the estimation results are, nevertheless, similar for the two models.     

饮水思源

水是地球上一切生命的源泉，万物都要依靠水才能生存。 在今天，世界范围的水危机已是一个迫切需要解决的问题，尤其是发展中的国家几乎都面临着缺水的危机，我国已被国际社会列入到世界最缺水国家的“黑名单”里。水资源短缺已经成为制约我国经济、社会发展的一个主要因素。除了自然地理条件和人们消费观念上的因素外，环境的污染也在日益消耗着本已短缺的水资源，使得水体水质从总体上呈恶化趋势。 目前，仅全国城市的生活污水一项就有大量的未经处理便排入江河湖泊。例如：以乡镇个体私营经济发达闻名的温州市，由于生产和生活污水…     

Should educational expenses be deductible?: A comparison of tax bases in a model where education is a choice variable

The paper studies the design of an educational policy within the context of an optimal taxation model where individuals are free to choose how much education to acquire, and also have a discrete labor-leisure choice. A linear income tax and tax deductibility of educational expenses are the only instruments available to the government, whose goal it is to use these instruments so as to maximize the utility of the worst off individual in society. The main focus of the study is how large a fraction of educational expenses should be deductible. A variation of this fraction has several opposing effects. The optimal size of the fraction depends therefore in a complicated way on the distribution of ability, the costs of producing education, and the effect of education on wages and productivity. There is no general case either for no deductibility or for full deductibility.     

Optimality: where competition fails and monopoly succeeds

Where, initially, the demand curve is a marginal curve and the supply curve is an average curve, ‘exploitation’ only of the supply curve, transforming it into a marginal curve, is required. If, initially, the reverse is true, optimality requires that the demand curve alone be ‘exploited’.