Testable consequences of economic theoryRID=""ID=""This is the written version of a conference delivered at the University of Calabria for the 1999 meeting of AMASES. The author is grateful to AMASES for their invitation.

This is a review of recent results on the disaggregation problem: given a collective demand function, is it or is it not the sum of individual demand functions, and, if it is, can one retrieve the individual demands from their given sum? There are several variants to this problem, depending on whether one deals with market demand or excess demand, but the general philosophy remains the same: to get interesting answers, i.&nspace;e. to be able to discriminate between those collective demand functions which arise from individual utility maximization and those which do not, one needs microeconomic data (e.pg., the individual allowances).     

Valuing Mangrove-Fishery Linkages – A Case Study of Campeche, Mexico

This paper explores the value of mangrove systems as a breeding and nursery habitat for off-shore fisheries, focusing on mangrove-shrimp production linkages in Campeche State, Mexico. We develop an open access fishery model to account explicitly for the effect of mangrove area on carrying capacity and thus production. From the long-run equilibrium conditions of the model we are able to establish the key parameters determining the comparative static effects of a change in mangrove area on this equilibrium. We then estimate empirically the effects of changes in mangrove area in the Laguna de Terminos on the production and value of shrimp harvests in Campeche over 1980–90. Our findings suggest that mangroves are an important and essential input into the Campeche shrimp fishery, but that the low levels of deforestation between 1980 and 1990 mean that the resulting losses to the shrimp fishery are still comparatively small. Over-exploitation of the fishery due to open access conditions remains the more pervasive threat, and without better management any long-run benefits of protecting mangrove habitat are likely to be dissipated.     

Do Open Access Conditions Affect the Valuation of an Externality? Estimating the Welfare Effects of Mangrove-Fishery Linkages in Thailand

Mangroves are considered ecologicallyimportant due to their role as breedinggrounds and nursery habitats for off-shorefisheries. However, mangrove deforestationthrough conversion to shrimp aquaculturethreatens this valuable function. This paperdevelops a dynamic production functionapproach to analyze the influence of habitatchanges on an open access fishery that faces afinite elasticity of demand. The basic modelis applied to a case study of the impacts ofmangrove deforestation on the artisanal marinedemersal and shellfish fisheries in Thailand. By estimating parameters through pooledtime-series and cross-sectional data over the1983–1993 period for the five coastal zones ofSouthern Thailand, the welfare impacts ofmangrove deforestation are estimated underdifferent elasticity of demand assumptions. Under pure open access, the welfare lossesestimated for mangrove deforestation inThailand of 30 km² annually ranged from$12,000 to $408,000 depending on theelasticity of demand.     

Multifunctionality of agriculture: an inquiry into the complementarity between landscape preservation and food security

Without support, the levels of agricultural public goods suchas food security and landscape preservation would fall shortof demand in high-cost countries. However, as demonstrated byNorway as a case study, the current level of support is disproportionatefrom a public goods perspective, and the policy instrumentsare badly targeted at the public goods in question. Becauseagricultural land is a major component of both food securityand landscape preservation, giving rise to a high degree ofcost complementarity between the public goods, it would be moreefficient to support land-extensive production techniques thanproduction per se.     

The purchase of moral positions: an essay on the markets of concerned parenting

The markets directed towards the very youngest are rapidly expanding. This article looks into the mechanisms behind the expansion of this type of parental consumption, assigning children a position similar to what Veblen categorized as vicarious consumption. The assumption put forward is that the modern markets for babies and toddlers rooted not only in the need to stimulate, protect and support the child, or the desire to display cultural and economic capital through vicarious consumption, but also in the need to indicate positions in the moral economy of concerned parenting. The expanding markets of considered consumption are partly based on translation values, empathy and care made into tangible products with symbolic values in the moral economy.     

Determinants of social desirability bias in sensitive surveys: a literature review

Survey questions asking about taboo topics such as sexual activities, illegal behaviour such as social fraud, or unsocial attitudes such as racism, often generate inaccurate survey estimates which are distorted by social desirability bias. Due to self-presentation concerns, survey respondents underreport socially undesirable activities and overreport socially desirable ones. This article reviews theoretical explanations of socially motivated misreporting in sensitive surveys and provides an overview of the empirical evidence on the effectiveness of specific survey methods designed to encourage the respondents to answer more honestly. Besides psychological aspects, like a stable need for social approval and the preference for not getting involved into embarrassing social interactions, aspects of the survey design, the interviewer’s characteristics and the survey situation determine the occurrence and the degree of social desirability bias. The review shows that survey designers could generate more valid data by selecting appropriate data collection strategies that reduce respondents’ discomfort when answering to a sensitive question.     

Predators in the market: implications of market interaction on optimal resource management

A two-species bioeconomic model is analyzed, but in contrast to most similar models, there is no biological interaction between the species, only economic. The interaction takes place in the market where the quantity of either species may affect the price of the other. The effects of cross-price elasticities on the optimal steady state and on the optimal paths in the sole-owner case are investigated both analytically (steady states) and numerically (optimal paths). First, it is shown that if the harvest of one species has impact on the price of another species, then this has a positive effect on its steady-state stock. The effect increases with the stock-elasticity in the cost function. Further, in the case of linear demand functions, the steady state outcome depends solely on the sum of the cross-price parameters and not their individual values. Secondly, in the investigation of optimal paths, it is shown that if the harvest of one species has impact on the price of the other, optimal trajectories reach steady state faster for itself and slower for the other species. Further, when cross-price elasticities are sufficiently high, the paths go from being monotonic to feature over- or undershooting.     

Matching for teams

We are given a list of tasks Z and a population divided into several groups X _j of equal size. Performing one task z requires constituting a team with exactly one member x _j from every group. There is a cost (or reward) for participation: if type x _j chooses task z, he receives p _j (z); utilities are quasi-linear. One seeks an equilibrium price, that is, a price system that distributes all the agents into distinct teams. We prove existence of equilibria and fully characterize them as solutions to some convex optimization problems. The main mathematical tools are convex duality and mass transportation theory. Uniqueness and purity of equilibria are discussed. We will also give an alternative linear-programming formulation as in the recent work of Chiappori et al. (Econ Theory, to appear).