Model selection in random effects models for directed graphs using approximated Bayes factors

With the development of an MCMC algorithm, Bayesian model selection for the p ₂ model for directed graphs has become possible. This paper presents an empirical exploration in using approximate Bayes factors for model selection. For a social network of Dutch secondary school pupils from different ethnic backgrounds it is investigated whether pupils report that they receive more emotional support from within their own ethnic group. Approximated Bayes factors seem to work, but considerable margins of error have to be reckoned with.     

Integrating ecosystem services into conservation assessments: A review

A call has been made for conservation planners to include ecosystem services into their assessments of conservation priority areas. The need to develop an integrated approach to meeting different conservation objectives and a shift in focus towards human wellbeing are some of the motivations behind this call. There is currently no widely accepted approach to planning for ecosystem services. This study contributes towards the development of this approach through a review of conservation assessments and the extent to which they include ecosystem services. Of the 476 conservation assessments identified by a set of search terms on the Web of Science, 100 were randomly selected for this review. Of these only seven had included ecosystem services, while another 13 had referred to ecosystem services as a rationale for conservation without including them in the assessment. The majority of assessments were based on biodiversity pattern data while 19 used data on ecological processes. A total of 11 of these 19 assessments used processes, which could be linked to services. Ecosystem services have witnessed an increase in attention received in conservation assessments since the year 2000, however trends were not apparent beyond this date. In order to assess which types of ecosystem services and how they have been accounted for in conservation assessments, we extended our review to include an additional nine conservation assessments which included ecosystem services. The majority included cultural ecosystem services, followed by regulatory, provisioning and supporting services respectively. We conclude with an analysis of the constraints and opportunities for the integration of ecosystem services into conservation assessments and highlight the urgent need for an appropriate framework for planning for ecosystem services.     

Component efficient solutions in line-graph games with applications

Recently, applications of cooperative game theory to economic allocation problems have gained popularity. We investigate a class of cooperative games that generalizes some economic applications with a similar structure. These are the so-called line-graph games being cooperative TU-games in which the players are linearly ordered. Examples of situations that can be modeled like this are sequencing situations and water distribution problems. We define four properties with respect to deleting edges that each selects a unique component efficient solution on the class of line-graph games. We interpret these solutions and properties in terms of dividend distributions, and apply them to economic situations. This research has been done while the third author was visiting Tinbergen Institute at the Free University, Amsterdam. The research is part of the Research Programme “Strategic and Cooperative Decision Making” at the Department of Econometrics. Financial support from the Netherlands Organization for Scientific Research (NWO) in the framework of the Russian-Dutch programme for scientific cooperation, is gratefully acknowledged. The third author also appreciates partial financial support from the Russian Leading Scientific Schools Fund (grant 80.2003.6) and Russian Humanitarian Scientific Fund (grant 02-02-00189a). We thank three anonymous referees for their valuable comments.     

All in the family or public? Law and appropriative costs as determinants of ownership structure

We examine how the legal protection of outside shareholders and the appropriative costs that they induce influence the incentives for private firms to go public. A higher degree of protection of shareholders can increase the appropriative costs associated with the conflict between managers and shareholders. To counteract this effect the managers/owners increase the share of the firm they retain so that, overall, higher protection of outsiders increases the likelihood of going public. In addition, we examine how the share of funds raised used to finance the firm affects both appropriative costs and the decision to sell.For helpful comments we thank participants at the conference on Corporate Governance at UC Irvine (February 2002), seminar participants at the Athens University of Economics and Business, and worskshop participants on the New Organization of Labour at the 2002 CESifo summer Institute in Venice. Skaperdas gratefully acknowledges support from a grant for Research and Writing from the John D. and Catherine T. MacArthur Foundation.     

Decomposing Redistributive Effects of Taxes and Transfers in Australia: Annual and Lifetime Measures

This paper decomposes the redistributive effect on annual and lifetime inquality of a range of taxes and transfers in Australia, using a dynamic cohort lifetime simulation model. The redistributive effect is decomposed into vertical, horizontal and reranking effects. Horizontal inequities in the tax and transfer system are found to be negligible. The extent of reranking is greater in the lifetime than in the annual context and is affected by the equivalence scales used to adjust household incomes. If no adjustment is made to household incomes, reranking is about nine per cent of the reduction in lifetime inequality. However, if each child is counted as equivalent to one-third of an adult, reranking is found to be less than one per cent.