FACTORS AFFECTING WELFARE GAINS FROM FISHING GEAR RESTRICTIONS

While the use of gear restrictions to regulate fishing activity seldom has the objective of improving economic efficiency, it is capable of achieving that result under some conditions. It can also reduce economic efficiency. This paper explores the way several factors affect the sign and magnitude of welfare gains from fishing gear restrictions. These factors include, among others: the fixity or variability of the price of fish and the presence or absence of diminishing short-run average product of effort. Some generalizations are offered regarding the characteristics of fisheries in which gear restrictions are most likely to produce welfare gains.Resource /Energy Economics and Policy,

You can't take it with you: asset run-down at the end of the life cycle

This article presents evidence on the extent to which households run down their assets after retirement. The authors show that, once corrections are made for several econometric problems, households engage in very little asset decumulation after retirement.Retirement ; Income ; Wealth

Trade Costs

This paper surveys the measurement of trade costs --- what we know, and what we don't know but may usefully attempt to find out. Partial and incomplete data on direct measures of costs go together with inference on implicit costs from trade flows and prices. Total trade costs in rich countries are large. The ad valorem tax equivalent is about 170% when pushing the data very hard. Poor countries face even higher trade costs. There is a lot of variation across countries and across goods within countries, much of which makes economic sense. Theory looms large in our survey, providing interpretation and perspective on the one hand and suggesting improvements for the future on the other hand. Some new results are presented to apply and interpret gravity theory properly and to handle aggregation appropriately.

Higher-order perturbation solutions to dynamic, discrete-time rational expectations models

We present an algorithm and software routines for computing nth order Taylor series approximate solutions to dynamic, discrete-time rational expectations models around a nonstochastic steady state. The primary advantage of higher-order (as opposed to first- or second-order) approximations is that they are valid not just locally, but often globally (i.e., over nonlocal, possibly very large compact sets) in a rigorous sense that we specify. We apply our routines to compute first- through seventh-order approximate solutions to two standard macroeconomic models, a stochastic growth model and a life-cycle consumption model, and discuss the quality and global properties of these solutions.Macroeconomics - Econometric models ; Business cycles ; Monetary policy

Borders, Trade and Welfare

International economic integration yields large potential welfare effects, even in a static constant returns competitive world economy. Our method is novel. The effect of border barriers on trade flows is often inferred from gravity models. But their rather atheoretic structure precludes welfare analysis. Computable general equilibrium models are designed for tight welfare analysis, but lack econometric foundation. Our method combines these approaches. Gravity models based on Anderson's (1979) interpretation are full general equilibrium models of a special simple sort. In Anderson and van Wincoop (NBER WP 8079, 2001) we develop and estimate this structure, then calculate the comparative static effects on trade flows of border barriers. In this paper we further deploy the model to explore the comparative statics of welfare with respect to borders, to currency unions and to NAFTA. Our NAFTA exercise does a much better job of replicating the actual trade flow changes than do computable general equilibrium models. An interesting implication is that terms of trade changes are very important, even for small' countries such as Mexico.

Subtidal algal community structure in kelp beds around the Cape Peninsula (Western Cape, South Africa)

The subtidal understorey seaweed communities were studied along a coastal distance of 104 km around the Cape Peninsula, which is situated in an overlap region between two marine provinces and characterized by a considerable temperature gradient. Sampling was carried out at six sites (4 to 10 quadrats per site) around the Cape Peninsula. For each of the quadrats, biomass of each species, grazing, and environmental variables such as temperature, wave exposure and sand cover were determined. The data were analysed using canonical correspondence analysis (CCA) and two way indicator species analysis (TWINSPAN). A total of 142 seaweed taxa were found at the six sites (21 Chlorophyta, 14 Phaeophyta and 107 Rhodophyta). The two sides of the Peninsula have a very different biomass-composition of Chlorophyta, Phaeophyta and Rhodophyta. The biomass of Rhodophyta in the Atlantic sites is much higher than in the Bay, and the biomass of Chlorophyta is higher in False Bay than on the west coast. A change in floristic composition of subtidal algal communities around the Cape Peninsula can be observed and is principally related to seawater temperature and wave exposure. Next to these physical factors, grazing is demonstrated to be important in determining species composition. A lower degree of wave exposure might result in a higher number of grazers in False Bay. The occurrence of a higher cover of encrusting corallines in the Bay is probably a consequence of the higher grazing pressure. Distinct community types can be recognized from TWINSPAN and CCA