Use of a Simple Age-Structured Bioeconomic Model to Estimate Optimal Long-Run Surpluses

When the New Zealand government introduced individual transferable quotas for major commercial fish stocks, the initial allocation for some stocks exceeded their total allowable catches and made it necessary to buy back immediately some of the quota. Quota was offered back by tender. A simple age-structured bioeconomic model was used to estimate long-run optimal surpluses. From these, the maximum prices that should be paid by government for quota were derived. The use of an age-structured model proved convenient for this purpose as the necessary parameter estimates tend to arise naturally from literature sources and the population dynamics are transparent. If stocks were managed optimally, the long-run value of quota would be equivalent to the net present value of the surplus at the dynamic maximum economic yield. Long-run surpluses proved to be dependent on the relative changes in catch rates and costs of fishing which resulted from changes in stock biomass. Optimal surpluses of up to 45% of the greenweight revenues were obtained for heavily exploited, long-lived stocks. Only small long-run surpluses were obtained for short-lived or very lightly exploited stocks.Environmental Economics and Policy, Resource /Energy Economics and Policy,

The Design of a Carbon Tax

We consider the design of a tax on greenhouse gas emissions for a developed country such as the United States. We consider three sets of issues: the optimal tax base, issues relating to the rate (including the use of the revenues and rate changes over time) and trade. We show that a well-designed carbon tax can capture about 80% of U.S. emissions by taxing fewer than 3,000 taxpayers and up to almost 90% with a modest additional cost. We recommend full or partial delegation of rate setting authority to an agency to ensure that rates reflect new information about the costs of carbon emissions and of abatement. Adjustments should be made to the income tax to ensure that a carbon tax is revenue neutral and distributionally neutral. Finally, we propose an origin-based system for trade with countries that have an adequate carbon tax and a system of border taxes for imports from countries without a carbon tax. We suggest a system that imposes presumptive border tax adjustments with the ability of an individual firm to prove that a different rate should apply. The presumptive tax could be based either on average emissions for production of the item by the exporting country or by the importing country.

Allocating Transmission to Mitigate Market Power in Electricity Networks

Allocating Transmission to Mitigate Market Power in Electricity Network

Diffusion coefficients for multi-step persistent random walks on lattices

We calculate the diffusion coefficients of persistent random walks on lattices, where the direction of a walker at a given step depends on the memory of a certain number of previous steps. In particular, we describe a simple method which enables us to obtain explicit expressions for the diffusion coefficients of walks with two-step memory on different classes of one-, two- and higher-dimensional lattices.Comment: 27 pages, 2 figure