Threshold models for trended time series

This paper presents the theoretical development of a new threshold autoregressive model based on trended time series. The theoretical arguments underlying the model are outlined and a nonlinear economic model is used to derive the specification of the empirical econometric model. Estimation and testing issues are considered and analysed. Additionally we apply the model to the empirical investigation of U.S. GDP.This paper is the result of work carried out for the author's Ph.D. thesis. I would like to thank Hashem Pesaran for his help, encouragement and insights during the preparation of this paper. I also thank Gary Koop and Sean Holly for helpful comments. Financial assistance from the Economic and Social Research Council is gratefully acknowledged.     

Regulatory Restrictions on Vertical Integration and Control: The Competitive Impact of Gasoline Divorcement Policies

Gasoline divorcement regulations restrict the integration of gasoline refiners and retailers. Theoretically, vertical integration can harm competition, making it possible that divorcement policies could increase welfare; alternatively, these policies may reduce welfare by sacrificing efficiencies. This paper attempts to differentiate between these possibilities by estimating a reduced form equation for the real retail price of unleaded regular gasoline. I find that divorcement regulations raise the price of gasoline by about 2.6¢ per gallon, reducing consumers surplus by over $100 million annually. This finding suggests that current proposals to further separate gasoline retailing from refining will be harmful to gasoline consumers.     

Corporate Lobbying, Regulatory Conduct and the Porter Hypothesis

Michael Porter, the influential Harvard management guru, has promoted the idea that compliance with stricter environmental regulations can afford secondary benefits to firms through improved product design, innovation, corporate morale and in other ways. Once these secondary benefits are factored, the net cost of compliance is argued to be lower than conventionally thought and may even be negative. Whilst environmental economists have rejected the Porter Hypothesis as being based on excessively optimistic expectations of the likely size of such secondary benefits the underlying ideas do enjoy significant credence in the business community. In the context of a lobbying model of regulatory policy-making we argue that the EPA should change the way it conducts regulatory policy to take account of Porter's views – even if it knows those views to be misguided. The model serves to illustrate the more general point that fashions in management thinking can be expected to impact the optimal conduct of regulatory policy.     

How to control a chaotic economy?

An economic system which exhibits chaotic behaviour has been stabilized on various periodic orbits by use of the Ott-Grebogi-Yorke method. This procedure has been recently applied to controlling chaotic phenomena in physical, chemical and biological systems. We adopt this method successfully for Feichtinger's generic model of two competing firms with asymmetrical investment strategies. We show that the application of this control method to the particular economic process considered brings a substantial advantage: one can easily switch from a chaotic trajectory to a regular periodic orbit and simultaneously improve the system's economic properties. Numerical simulations are presented in order to illustrate the effectiveness of the whole procedure.The work was supported by the Alexander von Humboldt-Stiftung and by the Polish National Council (KBN) Grant No 2 P302 038 04.     

Nonresponse in Contingent Valuation-reducing uncertainty in value inference

This paper focuses on problems associated with nonresponse in Contingent Valuation surveys. The results from a telephone follow-up survey show that value inference can be considerably improved by information on nonrespondents' attitudes.     

A Permanent Income Model of Public Consumption

This paper tests the permanent income hypothesis (PIH) for public consumption. Unlike private agents, a government is a representative national, infinitely-lived agent that usually faces no liquidity constraints. Thus, the expectation is that the PIH restrictions should not be rejected for public consumption. However, using U.S. data, the paper is unable to find evidence supporting the permanent income model of public consumption. Public consumption is found to be sensitive to lagged public income and too smooth relative to permanent public income. The results therefore cast doubt on the characterization of the public sector as a social welfare optimizing agent.