Air pollution-mortality models: A demonstration of the effects of random measurement error

Errors of measurement have long been recognized as a chronic problem in statistical analysis. Although there is a vast statistical literature of multiple regression models estimating the air pollution-mortality relationship, this problem has been largely ignored. It is well known that pollution measures contain error, but the consequences of this error for regression estimates is not known. We use Lave and Seskin's air pollution model to demonstrate the consequences of random measurement error. We assume a range of 0% to 50% of the variance of the pollution measures is due to error. We find large differences in the estimated effects on mortality of the pollution variables as well as the other explanatory variables once this measurement error is taken into account. These results cast doubt on the usual regression estimates of the mortality effects of air pollution. More generally our results demonstrate the consequences of random measurement error in the explanatory variable of a multiple regression analysis and the misleading conclusions that may result in policy research if this error is ignored.     

Structural instability of the core

Let σ be a q-rule, where any coalition of size q, from the society of size n, is decisive. Let w(n,q)= 2q-n+1 and let W be a smooth ‘policy space’ of dimension w. Let U(W)^N be the space of all smooth profiles on W, endowed with the Whitney topology. It is shown that there exists an ‘instability dimension’ w^*(σ) with 2w^*(σ)w(n,q) such that:

1. (i) if ww^*(σ), and W has no boundary, then the core of σ is empty for a dense set of profiles in U(W)^N (i.e., almost always),

2. (ii) if ww^*(σ)+1, and W has a boundary, then the core of σ is empty, almost always,

3. (iii) if ww^*(σ)+1 then the cycle set is dense in W, almost always,

4. (iv) if ww^*(σ)+2 then the cycle set is also path connected, almost always.

The method of proof is first of all to show that if a point belongs to the core, then certain generalized symmetry conditions in terms of ‘pivotal’ coalitions of size 2q−n must be satisfied. Secondly, it is shown that these symmetry conditions can almost never be satisfied when either W has empty boundary and is of dimension w(n,q) or when W has non-empty boundary and is of dimension w(n,q)+1.     

PROPRIETORIAL CONTROL IN FAMILY FIRMS: SOME FUNCTIONS OF 'QUASI-ORGANIC' MANAGEMENT SYSTEMS

The purpose of this paper is to investigate the strategies of managerial control which are used by the proprietors of family-owned business enterprises. Interviews with the proprietors and senior managers of businesses in the building industry illustrate the ‘quasi-organic’ nature of management structures. These grant some autonomy to senior managers without threatening proprietorial decision-making prerogatives. Although the family firm has certain distinctive features, similar control strategies designed to ensure that delegated decisions are ‘reliable’ and ‘responsible’ are evident in various types of business enterprise. There is, then, scope for further comparative research within a conceptual framework which does not entirely divorce the family firm from other business organizations.     

Finding a Nash equilibrium in spatial games is an NP-complete problem

Summary. We consider the class of (finite) spatial games. We show that the problem of determining whether there exists a Nash equilibrium in which each player has a payoff of at least k is NP-complete as a function of the number of players.Received: 15 September 2002, Revised: 9 March 2003, JEL Classification Numbers: C72.Correspondence to: H. HallerWe thank a referee for helpful comments. The hospitality of the Institute of Economics, University of Copenhagen, and the Institute for Advanced Studies, Vienna, is gratefully acknowledged by the third author.     

Asymmetric FDI and tax-treaty bargaining: theory and evidence

Tax treaties are often viewed as a mechanism for eliminating tax competition, however, this approach ignores the need for bargaining over the treaty's terms. This paper focuses on how bargaining can affect the withholding taxes set under the treaty. In a simple framework, we develop hypotheses about patterns in treaty tax rates. A key determinant for these patterns is the relative size of bilateral foreign direct investment (FDI) activity. In plausible situations, more asymmetric countries will negotiate treaties with higher tax rates. This theory is then tested using 1992 data from US and Organization for Economic Cooperation and Development (OECD) bilateral tax treaties. Overall, the data supports the prediction that greater asymmetric FDI activity increases the negotiated tax rates.     

Evaluation of national foresight activities: Assessing rationale, process and impact

The paper addresses the question of what constitutes an appropriate evaluation strategy for national foresight activities in different situations. The variety of rationales for foresight is explored, ranging from a desire to set priorities through to participation-oriented goals and building new networks around common visions and strategies. A generational model of foresight is used to show the evolution of key evaluation issues. The generic motivations for evaluation of accountability, justification and learning are discussed in the context of foresight. Evaluation grounded in the concept of behavioural additionality and the systems failure rationale is shown to be more suited as a rationale for foresight as public policy.Assessing the effects of foresight requires an understanding that it is only one of several influences on public policy. To be effective it needs to be tuned into the strategic behaviour and cycles of policy and economic actors. Cases are presented of evaluation of foresight programmes in the United Kingdom, Germany and Hungary. It is concluded that there is no “one-size-fits-all” evaluation approach and that the method selected is conditioned by motivation, timing and the level of aggregation. Foresight cannot be fully evaluated independently from its context. Foresight is being strengthened by the emergence of rigorous and systematic knowledge to assist learning and improvement.     

Late entry,market shares and competitive survival: The case of synthetic fibers

This paper examines product policy in relation to the experience curve and product life cycle concepts in the context of the experience of the thirteen major firms in the Western European synthetic fibers industry. It examines the hypothesis based on Boston Consulting Group and the Profit Impact of Market Share (PIMS) evidence that late entrants to a market will be at a competitive disadvantage because they lack the accumulated experience of the pioneering firms. For each of the three main synthetic fibres, acrylic, nylon and polyester, it was found that the early entrants who established major market shares early in the growth phase of the product life cycle were able to maintain that leadership nearly twenty years later. In contrast not only did almost all the late entrants fail to achieve significant market shares but in the difficult market conditions between 1974 and 1981 they provided seven out of nine market withdrawals.