Declining Discount Rates: The Long and the Short of it

The last few years have witnessed important advances in our understanding of time preference and social discounting. In particular, several rationales for the use of time-varying social discount rates have emerged. These rationales range from the ad hoc to the formal, with some founded solely in economic theory while others reflect principles of intergenerational equity. While these advances are to be applauded, the practitioner is left with a confusing array of rationales and the sense that almost any discount rate can be justified. This paper draws together these different strands and provides a critical review of past and present contributions to this literature. In addition to this we highlight some of the problems with employing DDRs in the decision-making process, the most pressing of which may be time inconsistency. We clarify their practical implications, and potential pitfalls, of the more credible rationales and argue that some approaches popular in environmental economics literature are ill-conceived. Finally, we illustrate the impact of different approaches by examining global warming and nuclear power investment. This includes an application and extension of Newell and Pizer [‘Discounting the benefits of climate change mitigation : how much do uncertain rates increase valuations?’ Journal of Environmental Economics and Management 46 (2003) 52] to UK interest rate data.     

On strategic complementarity conditions in Bertrand oligopoly

Summary. For Bertrand duopoly with linear costs, we establish via a single (counter-)example that: (i) A new monotone transformation of the firms' profit functions may lead to the supermodularity of transformed profits when the standard log and identity transformations both fail to do so, and (ii) Topkis's notion of critical sufficient condition for monotonicity of a Bertrand firm's best-reply correspondence cannot be extended to rely only on positive unit costs. Received: January 16, 2001; revised version: March 20, 2002 RID="*" ID="*" This work was completed while the first author was visiting the Institute for Industrial Economics at the University of Copenhagen during Spring 2000. Their financial support and stimulating research environment are gratefully acknowledged. The views expressed here are those of the authors and should not be attributed to the European Commission. Correspondence to: R. Amir     

On the real effects of inflation and inflation uncertainty in Mexico

We estimate an augmented multivariate GARCH-M model of inflation and output growth for Mexico at business cycle frequencies. The main findings are: (1) inflation uncertainty has a negative and significant effect on growth; (2) once the effect of inflation uncertainty is accounted for, lagged inflation does not have a direct negative effect on output growth; (3) However as predicted by Friedman and Ball, higher average inflation raises inflation uncertainty, and the overall net effect of average inflation on output growth in Mexico is negative. That is, average inflation is harmful to Mexican growth due to its impact on inflation uncertainty. (4) The Mexican Presidential election cycle significantly raises inflation uncertainty both during the year of the election and the year following the election which has correspondingly negative effects on output growth.     

Timing of Public Information and Cost Reduction

Received July 31, 2000; revised version received July 18, 2001     

旅行社价格战的博弈分析

旅行社是旅游产品设计、组织和销售的渠道商以及消费者之间的桥梁.旅行社对旅游业具有重要影响，旅行社之间的价格竞争日益严重，盈利率低。随着我国加入世贸组织，越来越多的外国旅行社进入我国、针对我国旅行社如何走出困境，本文从博弈角度分析旅行社的价格竞争及其对策。     

Competitive supply behavior when price information is fuzzy

The theory of fuzzy sets is applied to the output decisions of a price-taking firm facing imprecise information about expected future prices. Accepting risk resulting from the randomness of prices, the manager is interested in expected profits only. Since the set of possible expected-price vectors is fuzzy, a suitable defuzzification strategy is defined in analogy to the pessimism-optimism index proposed by L. Hurwicz. It depends on the manager's willingness to accept surprises resulting from a deviation of the true expected prices from the values that guided output decisions. Despite a linear cost function, well specified solutions to the optimization problem are possible without resorting to capacity constraints.     

Government as a discriminating monopolist in the financial market: the case of China

We show that the many unusual features of China’s financial markets are consistent with a government choosing regulations to maximize a standard type of social welfare function. Under certain conditions, these regulations are equivalent to imposing explicit taxes on business and interest income, yet should be much easier to enforce. The observed implicit tax rates are broadly in line with those observed in other countries. The theory also forecasts, however, that China will face increasing incentives over time to shift to explicit taxes.     

The damage costs of climate change toward more comprehensive calculations

It is argued that estimating the damage costs of a certain benchmark climate change is not sufficient. What is needed are cost functions and confidence intervals. Although these are contained in the integrated models and their technical manuals, this paper brings them into the open in order to stimulate discussion. After briefly reviewing the benchmark climate change damage costs, region-specific cost functions are presented which distinguish tangible from intangible losses and the losses due to a changing climate from those due to a changed climate. Furthermore, cost functions are assumed to be quadratic, as an approximation of the unknown but presumably convex functions. Results from the damage module of the integrated climate economy modelFUND are presented. Next, uncertainties are incorporated and expected damages are calculated. It is shown that because of convex loss functions and right-skewed uncertainties, the risk premium is substantial, calling for more action than analysis based on best-guess estimates. The final section explores some needs for further scientific research.     

不确定性情况下的居民资产组合行为与中国金融结构变迁

转轨经济的一个显著特点是各项制度不断变化,制度变迁带来的不确定性对居民资产选择行为产生重要影响,进而影响和决定了金融结构的形成与变迁.     

价格歧视战略与福利效应分析

在完全竞争市场条件下 ,竞争均衡可实现帕累托最优效率。垄断市场一般很难提供价格等于边际成本的产量水平 ,其产量与价格选择对社会来说不是最优的。垄断厂商以内生范畴和外生范畴为基础对消费者进行分类 ,使得价格歧视成为一种可行战略。由于定价策略存在差异 ,不同类型的价格歧视便具有不同的福利效应。