Reconciling economic and biological modeling of migratory fish stocks: Optimal management of the Atlantic salmon fishery in the Baltic Sea

The paper puts forward a model of the Atlantic salmon fishery in the Baltic Sea that integrates the salient biological and economic characteristics of migratory fish stocks. Designed to be compatible with the framework used for actual stock assessments, the model accounts for age-structured population dynamics, the seasonal harvest and competing harvesting by commercial and recreational fishermen. It is parameterized for the Simojoki River stock. The socially optimal policy for maximizing discounted net benefits from the fishery within an uncertain environment is determined using a dynamic programming approach and numerical solution method. Our results indicate that substantial economic benefits could be realized under optimal management without compromising stock sustainability.     

Tax-tariff reform with costs of tax administration

As is broadly recognised, the straightforward application of the Diamond–Mirrlees (1971) production efficiency theorem implies that when lump-sum taxation is not available, then it is optimal for the government in a small open economy to rely on taxes on the net demand of households rather than on border taxes to finance its resource requirements. However, the theorem does not hold when taxation is associated with administrative costs. The present paper explores the implications for optimal taxation and for desirable directions of tax-tariff reform of taking into account the costs of tax administration in countries at different levels of economic development. The paper clarifies the reasons for, and lends support to, the criticism by Stiglitz (Presentation to Congress of International Institute of Public Finance, Prague, 2003) of the IMF and the World Bank’s recommendation to developing countries to adopt VAT to replace border taxes.      

Option hedging theory under transaction costs

The problem of option hedging in the presence of proportional transaction costs can be formulated as a singular stochastic control problem. Hodges and Neuberger [1989. Optimal replication of contingent claims under transactions costs. Review of Futures Markets 8, 222–239] introduced an approach that is based on maximization of the expected utility of terminal wealth. We develop a new algorithm to solve the corresponding singular stochastic control problem and introduce a new approach to option hedging which is closer in spirit to the pathwise replication of Black and Scholes [1973. The pricing of options and corporate liabilities. Journal of Political Economy 81, 637–654]. This new approach is based on minimization of a Black–Scholes-type measure of pathwise risk, defined in terms of a market delta, subject to an upper bound on the hedging cost. We provide an efficient backward induction algorithm for the problem of cost-constrained risk minimization, whose associated singular stochastic control problem is shown to be equivalent to an optimal stopping problem. This algorithm is then modified to solve the singular stochastic control problem associated with utility maximization, which cannot be reduced to an optimal stopping problem. We propose to choose an optimal parameter (risk-aversion coefficient or Lagrange multiplier) in either approach by minimizing the mean squared hedging error and demonstrate that with this “best” choice of the parameter, both approaches have similar performance. We also discuss the different notions of risk in both approaches and propose a volatility adjustment for the risk-minimization approach, which is analogous to that introduced by Zakamouline [2006. European option pricing and hedging with both fixed and proportional transaction costs. Journal of Economic Dynamics and Control 30, 1–25] for the utility maximization approach, thereby providing a unified treatment of both approaches.     

An Incentive Water Pricing Policy for Sustainable Water Use

By adopting the Water Framework Directive (WFD), the European Commission (EC) and the European Council made recommendations for water pricing policies in European Union (EU) member states with a view to enhancing the sustainability of water resources. Clearly, the directive integrates economic instruments in environmental policies to provide incentives for the sustainable use of water resources. Our analysis will focus on public water utilities, required to be financially self-sufficient, facing demand and capacity shocks. The paper deals with the simultaneous determination of incentive pricing policies and investment rules under an ex~ante maximum demand charge. We will characterize the welfare-optimal capacity selection rule and the welfare-optimal maximum demand pricing rule. Heterogeneous consumers demands are considered when tariffs are set ex~ante, before demands are known. Our results are state-contingent nonlinear pricing that responds to demand fluctuations and capacity constraints.      

Optimal design of pro-conservation incentives

Payments for environmental services (PES) schemes have become an increasingly accepted and popular mode for governmental and non-governmental agencies to use in addressing local and regional declines in ecosystem services. In PES schemes, payments can either be tied to indicators of actions for service provision or to indicators of the generated service itself. Performance payments are synonymous for this second group, i.e. payments are completely contingent on the procurement of an environmental good or service. Such a focus raises several practical issues during implementation. We review and translate key aspects of the economic theory of incentives into the context of performance payment schemes with special attention paid to two practical issues: risks outside the individual's control and distortion in the measurement of environmental services. Four different incentive payment approaches are presented and the effects of risk and distortion on optimal incentives are discussed. The investigation of each payment approach is accompanied by a discussion of examples from the field.     

Optimality and efficiency of small chessboard designs for correlated errors

Optimal p × q row–column designs are obtained via complete enumeration of all possible designs for two treatments in some fixed effects models with errors specified by a doubly geometric covariance structure. This is done, in part, by a computer search, for a finite set of sizes of the correlation coefficients and in cases where p and q are small enough to make such a search feasible.     

一类商品销售系统的予测

本文对机理不清的动态销售系统,采用随机过程统计的方法建立 ARMA(p,q)模型,利用计算机处理,实现了对具有周期性的一类商品销售额的趋势予测,从而为实现类似问题提供了简便可行的予测方法。     

Optimal designs under two related models for interference

We consider two related models for interference: one having different directional neighbour effects and one with the same neighbour effects. We show that optimal designs for one model can be obtained from optimal designs for the other model. Acknowledgement. We are grateful to H. Kushner for advance notice of his work. SP was supported by the Isfahan University of Technology, Iran.     

财富、企业家才能与最优融资契约安排

本文认为企业家是企业发生的逻辑起点 ,是最初的“中心签约人” ,因此力图站在企业家的角度来考察企业家的融资行为。我们证明理性的企业家往往会将企业残值的优先索取权让度给外部投资者 ,从而否定了关于“投资者是最后的剩余索取者”的先验观点。在认识到“提供担保服务”是企业家自有资本的基本功能的基础上 ,我们揭示出一些关于企业家选择融资契约的规律。最后 ,我们还进一步发现即便未受财富约束 ,企业家也不会完全依靠自有资本来创业 ,因为很可能存在一个最优的企业家自有资本比例。     

Monetary policy, oil shocks, and TFP: Accounting for the decline in US volatility

An equilibrium model is used to assess the quantitative importance of monetary policy for the post-1984 decline in US inflation and output volatility. The principal finding is that monetary policy played a substantial role in reducing inflation volatility, but a small role in reducing real output volatility. The model attributes much of the decline in real output volatility to smaller TFP shocks. We also investigate the pattern of output and inflation volatility under an optimal monetary policy counterfactual. We find that real output volatility would have been somewhat lower, and inflation volatility substantially lower, had monetary policy been set optimally.