A new proof of the maximum principle

Summary. We offer a new proof of the maximum principle, by using the envelope theorem that is frequently used in the standard microeconomic theory. Received: April 11, 2002; revised version: June 26, 2002 Correspondence to: K. Shimomura     

Partisanship and the effectiveness of oversight

We examine the welfare effects of partisanship in a model of checks and balances. An executive makes a policy proposal and an overseer then decides whether or not to veto the executive's proposal. Both the executive and the overseer have private information as to the correct policy to pursue, and both are motivated by the desire to appear competent. A partisan overseer is one who, in addition to seeking to promote her own reputation, cares how her decision will impact the executive's reputation. Our main result is that partisanship can improve the efficacy of an oversight regime, as the distortions caused by a partisan overseer's desire to affect the executive's reputation can offset the distortions caused by her desire to enhance her own. Our results provide a new rationale for divided government, as partisan considerations are often necessary to prevent the overseer from rubber stamping all executive proposals.     

How much does household collateral constrain regional risk sharing?

We construct a new data set of consumption and income data for the largest US metropolitan areas, and we show that the extent of risk-sharing between regions varies substantially over time. In times when US housing collateral is scarce nationally, regional consumption is about twice as sensitive to income shocks. We also document higher sensitivity in regions with lower housing collateral. Household-level borrowing frictions can explain this new stylized fact. When the value of housing relative to human wealth falls, loan collateral shrinks, borrowing (risk-sharing) declines, and the sensitivity of consumption to income increases. Our model aggregates heterogeneous, borrowing-constrained households into regions characterized by a common housing market. The resulting regional consumption patterns quantitatively match those in the data.     

On the unique features of post-disaster humanitarian logistics

Logistic activity can be thought of as a socio-technical process whereby a social network of individuals orchestrates a series of technical activities using supporting systems such as transportation and communications. To understand the functioning of the entire system requires proper consideration of all its components. We identify seven key components: the objectives being pursued, the origin of the commodity flows to be transported, knowledge of demand, the decision-making structure, periodicity and volume of logistic activities, and the state of the social networks and supporting systems. Based on our analysis of the differences between commercial and humanitarian logistics, we pinpoint research gaps that need to be filled to enhance both the efficiency of humanitarian logistics and the realism of the mathematical models designed to support it.We argue that humanitarian logistics is too broad a field to fit neatly into a single definition of operational conditions. At one end of the spectrum we find humanitarian logistic efforts of the kind conducted in long-term disaster recovery and humanitarian assistance, where operational efficiency – akin to commercial logistics – is a prime consideration. At the other, post-disaster humanitarian logistic operations involved in disaster response and short-term recovery activities represent a vastly different operational environment, often in chaotic settings where urgent needs, life-or-death decisions and scarce resources are the norm. The huge contrast between these operational environments requires that they be treated separately.     

Too close for comfort? Distinguishing between team intimacy and team cohesion

The authors examine theory and research on team intimacy and team cohesion, and argue that the two have often been confused, merged, and used interchangeably in recent theoretical, empirical, and applied work on team effectiveness. The authors propose distinct definitions to clarify and distinguish between team intimacy and team cohesion, and suggest areas that will aid research and application. Their examination provides a framework for understanding the inconsistent findings in team effectiveness and team building research and thus helps to improve human resource management (HRM) interventions.     

Should the Good and the Selfish be Taxed Differently?*

In this paper, we consider an environment where individual actions have externalities and two types of agents exist: agents with social preferences (the good) and selfish agents. Selfish agents have pay‐off functions that do not take into account social welfare. The pay‐off of an agent is a linear combination of social welfare and the pay‐off of a selfish agent. We demonstrate that the corrective tax rates that maximize social welfare do not depend on the degree of social preferences. Hence, the good and the selfish should not be taxed differently.     

A Middle Class Image of Society

We studied undercoverage and nonresponse in a telephone survey among the population of the City ofGroningen, the Netherlands. The original sample, drawn from the municipal population register,contained 7000 individuals. For 37 percent of them, the telephone company was unable to produce a validtelephone number. Of those with a known telephone number, 49 percent did not answer the telephone orrefused to cooperate. As a result, the final respondents comprised merely 32 percent of the originalsample. To study distributional bias, we used individual-level data compiled from municipal records asour benchmark. Bivariate as well as multivariate analyses showed the undercoverage to be stronglyrelated to all sociodemographic variables studied, except gender. Nonresponse was related to age, countryof origin, marital status, and household size and composition, but not to gender, unemployment, socialassistance benefit, and education. Both undercoverage and nonresponse contributed to a strong middleclass bias in the final data set: middle-aged and older, economically secure people, of Dutch origin andliving with others in a household are overrepresented, while persons in disadvantaged and marginalpositions, such as the young, people of foreign stock, the unemployed, persons depending on publicincome support and singles are underrepresented.     

A never-decisive and anonymous criterion for optimal growth models

We address in this paper the question of the existence of a Social Welfare Function that would be sustainable and would allow us to obtain solutions to optimal growth models. We define sustainability by two new axioms called Never-decisiveness of the present and Never-decisiveness of the future. We first show that a SWF which has Never-decisiveness properties cannot be defined on a ball of $l_{\infty }^{+}$ . We must (i) restrict to the set of utility streams for which the value of the SWF is finite and (ii) introduce additional assumptions in order to obtain the Never-decisiveness properties. Our main result in this paper is therefore to show that the undiscounted utilitarian criterion is an anonymous and never-decisive criterion for optimal growth models. We consider the set of utilities of consumptions which are generated by a specific technology, namely a technology with decreasing returns for high levels of capital, and restrict ourselves to good programs, i.e., any program for which intertemporal utility is well defined.     

Heterogeneous Impact of Soil Contamination on Farmland Prices in the Belgian Campine Region: Evidence from Unconditional Quantile Regressions

We estimate a hedonic-pricing model using geo-coded farmland-transaction data from the Campine region, situated in the north-east of Belgium. Unlike previous hedonic studies, we use the method of unconditional quantile regression (Firpo et al., in Econometrica 77(3):953–973, 2009). An important advantage of this new method over the traditional conditional quantile regression (Koenker and Bassett, in Econometrica 46(1):33–50, 1978) is that it allows for the estimation of potentially heterogeneous effects of cadmium pollution along the entire (unconditional) distribution of farmland prices. Using a threshold specification of the hedonic-pricing model, we find evidence of a U-shaped valuation pattern, where cadmium pollution of the soil has a negative and significant impact on prices only in the middle range of the distribution, insofar as cadmium concentrations are above the regulatory standard of 2 parts per million for agricultural land. Results obtained from a probit model to classify land plots into different price segments further suggest that the heterogeneous impact of soil pollution on price can be directly related to the variety of amenities that farmland provides.