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.     

Post OPA-90 Vessel Oil Transfer Spill Prevention: The Effectiveness of Coast Guard Enforcement

Although oil spills from tanker accidents receive the most publicity, most vessel spills are not the result of accidents but of oil transfer activities. We investigate determinants of the size of vessel oil transfer spills as well as the effectiveness of Coast Guard enforcement activities in reducing their size. Vessel out-of-water and in-water oil transfer spillage functions are estimated utilizing tobit regression and detailed data on individual vessel oil transfer spills as well as Coast Guard safety/environmental enforcement activity data for the 1991–1995 period. Our estimation results suggest that Coast Guard hull but not machinery inspections are effective in reducing both out-of-water and in-water spills; patrols by air, but not by boat, are effective in reducing out-of-water spills; but neither is effective in reducing in-water spills. The results also show that the type of vessel (oil- and non-oil-cargo), vessel characteristics, vessel operations, weather/visibility conditions, and waterway type are determinants of post OPA-90 vessel oil transfer spills.     

Bargaining Outcomes with Double-Offer Arbitration

Increasingly, arbitration is becoming used to resolve bargaining disputes in a variety of settings. Reducing dispute rates is often listed as a main goal in designing arbitration mechanisms. Conventional arbitration and final-offer arbitration are two commonly used procedures, but theoretical examinations of these arbitration procedures show that disputants’ final bargaining positions do not converge and disagreement is likely. This article contains results from a set of experiments designed to compare bargaining outcomes under the two commonly used arbitration procedures with outcomes under an innovative procedure called “double-offer” arbitration (Zeng et al., 1996). This procedure requires that disputants make two final offers at impasse: a primary and a secondary offer. The arbitrator evaluates the pairs of offers using a linear criterion function, and theory suggests the secondary offers converge to the median of the arbitrator’s preferred settlement distribution. Because the procedure’s rules are that convergence of offers generates a settlement at those offers, this theoretical convergence result implies that arbitration is not needed in the end. Experimental results indicate that dispute rates in double-offer arbitration are, on average, about the same as dispute rates in conventional arbitration. However, other results show reason to favor double-offer arbitration. Specifically, in repeated bargaining, there is concern over whether use of an arbitration procedure becomes addictive and makes bargainers more likely to use the procedure in the future-a “narcotic effect.” The data show that double-offer arbitration is non-addictive, whereas both conventional and final-offer arbitration are.     

Vetoes Overridable by Simple Majorities

Conventional wisdom has it that the absolute (purely negative) veto is ineffective when overridable by a simple majority. That is flatly false. The examples that prove this surprising fact are themselves surprisingly ordinary yet oddly resistant to direct observation. They reveal virtues of a neglected institutional design.JEL classification: D71, D72     

Convenient estimators for the panel probit model: Further results

Bertschek and Lechner (1998) propose several variants of a GMM estimator based on the period specific regression functions for the panel probit model. The analysis is motivated by the complexity of maximum likelihood estimation and the possibly excessive amount of time involved in maximum simulated likelihood estimation. But, for applications of the size considered in their study, full likelihood estimation is actually straightforward, and resort to GMM estimation for convenience is unnecessary. In this note, we reconsider maximum likelihood based estimation of their panel probit model then examine some extensions which can exploit the heterogeneity contained in their panel data set. Empirical results are obtained using the data set employed in the earlier study. Helpful comments and suggestions by Irene Bertschek and Michael Lechner are gratefully acknowledged. This paper has also benefited from comments by two anonymous referees and from seminar participants at the Center for Health Economics at the University of York. Any remaining errors are the responsibility of the author.     

Noisy chaotic dynamics in commodity markets

The nonlinear testing and modeling of economic and financial time series has increased substantially in recent years, enabling us to better understand market and price behavior, risk and the formation of expectations. Such tests have also been applied to commodity market behavior, providing evidence of heteroskedasticity, chaos, long memory, cyclicity, etc. The present evaluation of futures price behavior confirms that the resulting price movements can be random, suggesting noisy chaotic behavior. Prices could thus follow a mean process that is dynamic chaotic, coupled with a variance that follows a GARCH process. Our conclusion is that models of this type could be constructed to assist in forecasting prices in the short run but not over long run time periods.First version received: June 2001/Final version received: March 2003     

The nature of the steady state in models of optimal growth under uncertainty

Summary. We study a one-sector stochastic optimal growth model with a representative agent. Utility is logarithmic and the production function is of the Cobb-Douglas form with capital exponent . Production is affected by a multiplicative shock taking one of two values with positive probabilities p and 1-p. It is well known that for this economy, optimal paths converge to a unique steady state, which is an invariant distribution. We are concerned with properties of this distribution. By using the theory of Iterated Function Systems, we are able to characterize such a distribution in terms of singularity versus absolute continuity as parameters and p change. We establish mutual singularity of the invariant distributions as p varies between 0 and 1 whenever . More delicate is the case . Singularity with respect to Lebesgue measure also appears for values such that . For and Peres and Solomyak (1998) have shown that the distribution is a.e. absolutely continuous. Characterization of the invariant distribution in the remaining cases is still an open question. The entire analysis is summarized through a bifurcation diagram, drawn in terms of pairs .Received: 9 April 2002, Revised: 29 October 2002, JEL Classification Numbers: C61, O41.Correspondence to: Tapan MitraThis research was partially supported by CNR (Italy) under the "Short-term mobility" program and by M.U.R.S.T. (Italy) National Group on "Nonlinear Dynamics and Stochastic Models in Economics and Finance" . We are indebted to Rabi Bhattacharya for providing us with the reference to Solomyak's (1995) paper. The present version has benefitted from comments by Mukul Majumdar and two anonymous referees.     

A theory of persistent income inequality

This paper explores the dynamics of income inequality by studying the evolution of human capital investment and neighborhood choice for a population of families. Parents affect the conditional probability distribution of their children's income through the choice of a neighborhood in which to live. Neighborhood location affects children both through local public finance of education as well as through sociological effects. These forces combine to create incentives for wealthier families to segregate themselves into economically homogeneous neighborhoods. Economic stratification combines with strong neighborhoodwide feedback effects to transmit economic status across generations, leading to persistent income inequality.     

Trade and Renewable Resources in a Second Best World: An Overview

We provide an overview and introduction to the emerging field of trade and renewable resources, and discuss the potential impact of trade liberalization on welfare and resource conservation. A key factor determining the effect of trade reform is the institutional context or property rights regime, and our survey is organized such that it loosely follows the development of new insights with respect to institutions in this literature. This implies a transition from the benevolent planners model to the polar opposite benchmark of open access in the 1990s. Currently the pendulum is swinging back towards management and regulation, but institutions are treated as endogenous. We discuss and compare various key models in some detail and search for common ground between protagonists and antagonists of free trade. Paper based on Keynote address by Erwin Bulte, 12th Annual Conference of the European Association of Environmental and Resource Economists, Bilbao (Spain), June 28–30, 2003.     

Punishment,counterpunishment and sanction enforcement in a social dilemma experiment

We present the results of an experiment that explores the sanctioning behavior of individuals who experience a social dilemma. In the game we study, players choose contribution levels to a public good and subsequently have multiple opportunities to reduce the earnings of the other members of the group. The treatments vary in terms of individuals’ opportunities to (a) avenge sanctions that have been directed toward themselves, and (b) punish others’ sanctioning behavior with respect to third parties. We find that individuals do avenge sanctions they have received, and this serves to decrease contribution levels. They also punish those who fail to sanction third parties, but the resulting increase in contributions is smaller than the decrease the avenging of sanctions induces. When there are five rounds of unrestricted sanctioning, contributions and welfare are significantly lower than when only one round of sanctioning opportunities exists, and welfare is lower than at a benchmark of zero cooperation. We thank James Andreoni, participants in seminars at Emory University, the University of Wisconsin-Madison, the University of New South Wales, the University of Sydney, Deakin University, the 2004 North American Regional Meetings of the ESA in Tucson, Arizona, USA, the 2004 IMEBE Meetings in Cordoba, Spain, and the 2005 SAET meetings in Vigo, Spain, for constructive and helpful comments. We thank Elven Priour for programming and organization of the sessions. Instructions for the experiment are available from the authors.