The Employed, the Unemployed, and the Unemployable: Directed Search with Worker Heterogeneity

We examine the implications of worker heterogeneity on the equilibrium matching process, using a directed search model. Worker abilities are selected from a general distribution, subject to some weak regularity requirements, and the firms direct their job offers to workers. We identify conditions under which some fraction of the workforce will be "unemployable": no firm will approach them even though they offer positive surplus. For large markets we derive a simple closed form expression for the equilibrum matching function. This function has constant returns to scale and two new terms, which are functions of the underlying distribution of worker productivities: the percentage of unemployable workers, and a measure of heterogeneity (?).The equilibrium unemployment rate is increasing in ? and, under certain circumstances, is increasing in the productivity of highly skilled workers, despite endogenous entry. A key empirical prediction of the theory is that ? ? 1. We examine this prediction, using data from several countries.Directed search; worker heterogeneity; unemployment

Instrument Choice in Environmental Policy

We examine the extent to which various environmental policy instruments meet major evaluation criteria, including cost-effectiveness, distributional equity, minimization of risk in the presence of uncertainty, and political feasibility. Instruments considered include emissions taxes, tradable emissions allowances, subsidies for emissions reductions, performance standards, technology mandates, and research and development subsidies. Several themes emerge. First, no single instrument is clearly superior along all the criteria. Second, significant trade-offs arise in the choice of instrument; for example, assuring a reasonable degree of distributional equity often will require a sacrifice of cost-effectiveness. Third, it is possible and sometimes desirable to design hybrid instruments that combine features of various instruments in their “pure” form. Fourth, for many pollution problems, more than one market failure may be involved, which may justify (on efficiency grounds, at least) employing more than one instrument. Finally, potential overlaps and undesirable interactions among environmental policy instruments are sometimes a matter of concern.emissions control instruments, cost-effectiveness, distributional burden, induced innovation

Dynamic and mass transfer phenomena of spherical capped bubbles

Imperial Users onl

Soccer and the American Dream

The American Dream is founded upon the ideological belief that ‘you can be anything you want to be, regardless of your current class position.’ This belief is contained within the dominant prevailing notion that the U.S. is a meritocracy where power and success are associated with determination and failure with laziness. This thesis challenges whether the American Dream is a relevant, attainable and viable concept for higher education students via the avenue of a soccer scholarship. In so doing, the research presented challenges the perceived wisdom of ‘American exceptionalism’ from a critical theoretical perspective. The research question at the heart of this study is ‘what are the motives of American university students for undertaking a soccer scholarship?’ The adoption of an interpretive paradigm for this study aims to provide an explanation of student decision-making. In the final analysis, this approach reveals what soccer means to the lives of the student-athletes. The central themes of the study were established via a pilot study and categorised as: family, social class, social mobility and career development. Questionnaires were completed by 154 students from two separate Division One universities. Twelve students were then purposively sampled and interviewed using a semi-structured format. To supplement these opinions, interviews were then conducted with a selection of coaches and athletic directors at the respective institutions. Analysis of the responses was contextualised using the framework provided by Csikszentmihayli and Schneider’s (2000) ‘Support/Challenge Questionnaire’. The findings support a common hypothesis that the family is a significant agent in socialising of their children to the cultural values of the American Dream. The findings additionally reveal support for the notion that families are important influences on their child’s sport mobility orientations in the soccer context. An alternative explanation proposed here is that the transmission process is actually a two-way dialogue in which children socialised their parents and vice versa. The family in this study represent a potentially problematic social process for the inculcation of values related to the maintenance of social life. The conclusions presented clearly reveal that the majority of students embarking on a soccer scholarship are motivated by the need to firstly finance their higher education and secondly to take part in a sport they have played since childhood. Students were aware of the uncertainty of the marketplace and the limitations of their own technical ability. As such their participation in the scholarship could be considered to be a pragmatic adaptation of a ‘labour of love.

When Can Carbon Abatement Policies Increase Welfare? The Fundamental Role of Distorted Factor Markets

This paper employs analytical and numerical general equilibrium models to assess the efficiency impacts of two policies to reduce U.S. carbon emissions — a revenue-neutral carbon tax and a non-auctioned carbon quota — taking into account the interactions between these policies and pre-existing tax distortions in factor markets. We show that tax interactions significantly raise the costs of both policies relative to what they would be in a first-best setting. In addition, we show that these interactions put the carbon quota at a significant efficiency disadvantage relative to the carbon tax: for example, the costs of reducing emissions by 10 percent are more than three times as high under the carbon quota as under the carbon tax. This disadvantage reflects the inability of the quota policy to generate revenue that can be used to reduce pre-existing distortionary taxes. Indeed, second-best considerations can limit the potential of a carbon quota to generate overall efficiency gains. Under our central values for parameters, a non-auctioned carbon quota (or set of grandfathered carbon emissions permits) cannot increase efficiency unless the marginal benefits from avoided future climate change are at least $17.8 per ton of carbon abatement. Most estimates of marginal environmental benefits are below this level. Thus, our analysis suggests that any carbon abatement by way of a non-auctioned quota will reduce efficiency. In contrast, our analysis indicates that a revenue-neutral carbon tax can be efficiency-improving so long as marginal environmental benefits are positive.

Realistic evaluation of hull performance for rowing shells, canoes, and kayaks in unsteady flow

In this study, we investigated the effect of hull dynamics in shallow water on the hydrodynamic performance of rowing shells as well as canoes and kayaks. An approach was developed to generate data in a towing tank using a test rig capable of reproducing realistic speed profiles. The impact of unsteady shallow-water effects on wave-making resistance was examined via experimental measurements on a benchmark hull. The data generated were used to explore the validity of a computational approach developed to predict unsteady shallow-water wave resistance. Comparison of measured and predicted results showed that the computational approach correctly predicted complex unsteady wave-resistance phenomena at low oscillation frequency and speed, but that total resistance was substantially under-predicted at moderate oscillation frequency and speed. It was postulated that this discrepancy arose from unsteady viscous effects. This was investigated via hot-film measurements for a full-scale single scull in unsteady flow in both towing-tank and field-trial conditions. Results suggested a strong link between acceleration and turbulence and demonstrated that the measured real-world viscous-flow behaviour could be successfully reproduced in the tank. Thus a suitable tank-test approach could provide a reliable guide to hull performance characterization in unsteady flow

A Critical Appraisal of the MODSS Process as Applied to Forestry in South-East Queensland and the Hodgson Creek Catchment

Part of a report for the RIRDC/Land & Water Australia/FWPRDC: Joint Venture Agroforestry Program, July 2002