Patterns and dynamics of population heterogeneity in mixtures models

Mixtures of distributions are a common modelling tool for durations of social phenomena, especially when the population is believed to be heterogeneous. We discuss heterogeneity patterns which can be captured by various mixing distributions in continuous and discrete time. Particular attention is given to recidivism data which Kaplan modeled by beta-mixtures of geometric distributions. We also investigate the dynamics of heterogeneity, measured via the variance of the mixing distribution, over the duration. It is shown that not all mixture models display decreasing heterogeneity over time.     

Two Dimensions of Convergence: National and International Wage Adjustment Effects of Cross-border Outsourcing in Europe

The paper proposes a distinction between the two dimensions of convergence—within and between countries—when analyzing the impact of cross‐border outsourcing on real wage rates in the EU‐15 and the CEEC. In the CEEC, international outsourcing has not affected the adjustment of average real wage rates at the manufacturing industry level, but it has led to a closure of the gap within a typical EU economy. Between‐country convergence is likewise fostered by cross‐border outsourcing, supporting the hypothesis that outsourcing facilitates international factor price equalization.     

WHAT ACCOUNTS FOR THE DECLINE IN CRIME?*

In this article we analyze recent trends in aggregate property crime rates in the United States. We propose a dynamic equilibrium model that guides our quantitative investigation of the major determinants of observed patterns of crime. Our main findings can be summarized as follows: First, the model is capable of reproducing the drop in crime between 1980 and 1996. Second, the most important factors that account for the observed decline in property crime are the higher apprehension probability, the stronger economy, and the aging of the population. Third, the effect of unemployment on crime is negligible. Fourth, the increased inequality prevented an even larger decline in crime. Overall, our analysis can account for the behavior of the time series of property crime rates over the past quarter century.     

Lies,damned lies and statistics: the accuracy of survey responses

That survey research is error prone is not a new idea and different varieties of non-sampling error have been investigated in the literature as well as consideration being given in many statistics textbooks to the issue of sampling error. The paper here considers research upon corporate environmental reporting. It compares information provided by corporate environmental reports with information that survey respondents claim their organization’s environmental report contains. This enables the accuracy of the claims to be assessed. Consideration is given to two different industries the Water industry and the Energy industry. Errors due to inaccurate reporting by survey respondents are shown to be relatively infrequent and respondents appear just about as likely to claim they report information that they do not, in fact, report as to fail to indicate that they report information that is, in fact, actually reported.     

Fashion centres: An approach to sector intervention

The clothing and textile industry is a major employer in many areas. It consists of a large number of small firms characterised by very poor working conditions. The need to sustain employment in the industry and improve conditions has led to several local authorities adopting a sector approach to intervention. This paper looks at the development of one particular measure, the establishment of fashion centres.     

Entry and growth in a perfectly competitive vintage model

A perfectly competitive vintage-knowledge model of Schumpeterian growth is introduced to study the relation between growth, technology-lifetime, entry, and productivity-dispersion. The incentive to innovate is generated by the productivity-dispersion (latent in traditional vintage models) between new and old plants, rather than by monopoly rents. The model has a unique steady-state REE with endogenous growth. The endogenous extent of entry constitutes a buffer, dampening the effect of research-efficiency and completely neutralizing the effect of population size or population growth rates on per-capita income levels and growth rates. Variations of research-efficiency lead to a negative relation between growth and vintage-lifetime and a non-monotonic relation between growth and productivity-dispersion.     

Environmental Taxation and Vertical Cournot Oligopolies: How Eco-industries Matter

This article specifies what an optimal pollution tax should be when dealing with a vertical Cournot oligopoly. Polluting firms sell final goods to consumers and outsource their abatement activities to an environment industry. It is assumed that both markets are imperfectly competitive. Thus, the tax is a single instrument used to regulate three sorts of distortions, one negative externality and two restrictions in production. Consequently, the optimal tax rate is the result of a trade-off that depends on the firms’ market power along the vertical structure. A detailed analysis of Cournot-Nash equilibria in both markets is also performed. In this context, the efficiency of abatement activities plays a key-role. It gives a new understanding to the necessary conditions for the emergence of an eco-industrial sector.      

Competition Policy: What are the Costs and Benefits of Measuring its Costs and Benefits?

Summary  Competition authorities are increasingly measuring the effects of their enforcement actions, seeking a robust justification for the proliferation of competition policy. We highlight the importance of identifying the right counterfactual against which to measure effects, and set out the relevant categories of costs and benefits. We then explore how a balance can be struck between the benefits and inherent limitations of these measurement exercises. Relatively crude analyses of cartel action benefits can be sufficient to achieve public legitimacy for competition policy. Assessing the effects of merger and conduct inquiries is often ambiguous, but could be used to improve decision-making processes. Director and Managing Consultant, respectively, at Oxera, Oxford and London. The valuable comments of Fod Barnes, Kerry Hughes and an anonymous referee are gratefully acknowledged. The opinions expressed in this article are those of the authors alone.