The physical Properties of marine sediments as inferred from Wavelet Correlation Analysis

Seismic waves traveling in the water/sediment or sub-bottom sediment interface have been the subject of considerable interest in underwater acoustics in recent years. Some progress has been made in understanding the propagation and attenuation characteristics of interface waves in different geological environments. However, the generating mechanisms are poorly understood. In particular, what is the acoustic-seismic energy conversion process? As seismic waves involve both time and space parameters it should be able to relate directly the propagation characteristics of the ocean bottom interface waves to the shear properties of the sediments over the propagation area. To address these problems we have applied the wavelet correlation method (WCR) to examine the variations of bottom characteristics and their role in coupling waterborne sound into the sea bottom. To confirm the validity of the developed modeling technique, we applied the wavelet correlation analysis for synthetic seismograms and field data. In this discussion paper we present images of the first and second shear modes and the interface wave component as a function of arrival time and frequency. We also discuss the possibility of inverting phase and group velocity information directly from the wavelet cross-correlation function and propose the way of using the WCR method to predict physical dynamic parameters of marine sediments.     

Value and exchange in law and economics: Buchanan versus posner

Meir Kohn’s Exchange and Value claims that economics can be organised around two opposed paradigms, the exchange and the value paradigms. In this paper, we apply this dichotomy to characterize the analyses proposed by economists in the field known as “law and economics”. We compare and contrasts the perspectives proposed by two prominent scholars—James Buchanan and Richard Posner—and argue that they, respectively, represent the exchange and the value paradigm in law and economics. More precisely, we show that Buchanan sticks to a definition of economics based on the exchange paradigm, and this leads him to define law and economics in a rather specific, different, narrower than Posner’s way to define law and economics—a definition that corresponds to a conception of economics based on the value paradigm.     

Modeling corner solutions with panel data: Application to the industrial energy demand in France

This paper provides an empirical application of Lee and Pitts (1986) approach to the problem of corner solutions in the case of panel data. This model deals with corner solutions in a manner consistent with the firm behavior theory while controlling for unobserved heterogeneity. In this model, energy demand at industrial plant level is the result of a discrete choice of the type of the energy to be consumed and a continuous choice that defines the level of demand. The econometric model is, essentially, an endogenous switching regime model which requires the evaluation of multivariate probability integrals. We estimate the random effect model by maximum likelihood using a panel of industrial French plants from the paper and pulp industry. We calculate empirical price elasticities of energy demand from the model. We also study the effects on energy demand of an environmental policy aimed at reducing CO₂ emissions. The authors are grateful to the Institut Français de eEnergie for its financial support and to the SESSI for providing the data. We would like to thank two anonymous referees for useful comments and suggestions. the usual disclaimer applies.     

Bargaining over an uncertain outcome:¶the role of beliefs

We study the Nash bargaining solution of a problem in which two agents bargain over an uncertain outcome. Under the assumptions of risk neutrality and of constant absolute risk aversion, we study the way that the solution varies, ex ante, when we vary the beliefs of one agent. Changing an agent's beliefs in a way that makes them “more distant” from the other agent's beliefs makes the second agent better off. Received: 10 May 2001 / Accepted: 22 August 2001     

Measuring common cyclical features during financial turmoil: Evidence of interdependence not contagion

This paper develops a test of contagion in financial markets by considering a measure of co-movement based on the notion of common cycles to detect short-run co-movements between a set of time series. We apply our methodology to the international effects of the 1994 Mexican peso crisis and the 1997 Asian crisis. Our results can be interpreted as evidence of a high level of market co-movement during all states of the world and, therefore, question the hypothesis of shift-contagion in the transmission of financial shocks during the 1997 Asian crisis, and to a lesser extent, the 1994 Mexican crisis.     

Genetically Modified Crops, Corporate Pricing Strategies, and Farmers' Adoption: The Case of Bt Cotton in Argentina

This article analyzes adoption and impacts of Bt cotton in Argentina against the background of monopoly pricing. Based on survey data, it is shown that the technology significantly reduces insecticide applications and increases yields; however, these advantages are curbed by the high price charged for genetically modified seeds. Using the contingent valuation method, it is shown that farmers' average willingness to pay is less than half the actual technology price. A lower price would not only increase benefits for growers, but could also multiply company profits, thus, resulting in a Pareto improvement. Implications of the sub-optimal pricing strategy are discussed.     

Multiple equilibria in a cash-in-advance two-sector economy

We consider a two-sector infinite horizon economy with a fractional cash-in-advance constraint on consumption expenditures. This formulation allows us to consider a steady-state velocity of money that is strictly greater than one and, therefore, provides a more plausible framework than the standard formulation in which all the consumption purchases are paid cash. We prove that the steady state is bound to be indeterminate and multiple equilibria occur when the share of the liquidity constraint is low enough and that a capital-intensive investment good or a strongly capital-intensive consumption good improve considerably the scope for indeterminacy. As a consequence, we show that without any restriction on the elasticity of intertemporal substitution in consumption, multiple equilibria might occur if the velocity of money is greater than a critical bound that is compatible with empirical estimates.