Improving lattice schemes through bias reduction

Lattice schemes for option pricing, such as tree or grid/partial differential equation (p.d.e.) methods, are usually designed as a discrete version of an underlying continuous model of stock prices. The parameters of such schemes are chosen so that the discrete version “best” matches the continuous one. Only in the limit does the lattice option price model converge to the continuous one. Otherwise, a discretization bias remains. A simple modification of lattice schemes which reduces the discretization bias is proposed. The modification can, in theory, be applied to any lattice scheme. The main idea is to adjust the lattice parameters in such a way that the option price bias, not the stock price bias, is minimized. European options are used, for which the option price bias can be evaluated precisely, as a template to modify and improve American option methods. A numerical study is provided. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:733–757, 2006     

Improving the speed of adoption of agricultural technologies and farm performance through farmer groups: evidence from the Great Lakes region of Africa

The article examines the effect of membership in farmer groups (MFG) on adoption lag of agricultural technologies and farm performance in Burundi, the Democratic Republic of Congo and Rwanda. We use duration and stochastic production frontier models on farm household data. We find that the longer the duration of MFG, the shorter the adoption lag and much more so if combined with extension service delivery. Farmer groups function as an important mechanism for improving farm productivity through reduced technical inefficiency in input use. We discuss policy implications under which farmer groups are a useful channel to reduce adoption lag, and the means through which improved farm performance can be achieved.     

Virtual Community Use for Packaged Software Maintenance

In this study, we investigated the use of virtual communities for involving distributed customers in the maintenance of packaged software. On the basis of an empirical study, we suggest that virtual communities can be usefully leveraged for corrective, adaptive, and perfective software maintenance. Specifically, the virtual community allowed for quick discovery of bugs and a rich interaction between developers and customers in the categories of corrective and adaptive software maintenance. However, although contributing also to the perfective category of software maintenance, this was the category in which several customer suggestions for modification were actually ignored by the developers. This implies that community use is indeed beneficial for maintenance related to coding and design errors as well as for maintenance of an adaptive character. However, it has limitations when associated with major changes such as software functionality addition or modification as those experienced in the category of perfective maintenance.     

Basel’s value-at-risk capital requirement regulation: An efficiency analysis

We analyze the optimal portfolio policies of expected utility maximizing agents under VaR Capital Requirement (VaR-CR) regulation in comparison to the optimal policy under exogenously-imposed VaR Limit (VaR-L) and Limited-Expected-Loss (LEL) regulations. With VaR-CR regulation the agent strategy consists of simultaneous decisions on both the portfolio VaR and on the implied amount of required eligible capital. As a result, the performance of VaR-CR regulation depends on its design (the parameter n) and the agent preferences. We show that an optimal VaR-CR regulation allows the regulator on the one hand, to completely eliminate the exposure to the largest losses, which may jeopardize the existence of the institution, and on the other hand, to restrain the portfolio exposure to all other losses. These results rationalize the current Basel regulations. However, the analysis shows also that there is an optimal level of required eligible capital from the regulator standpoint. Counter-intuitively, any requirement above this optimal level is inefficient as it leads to a smaller amount of actually maintained eligible capital and thereby to a larger exposure to the most adverse states of the world. Unfortunately, the current Basel’s range of required levels (n = 3–4) is within this inefficient range. Moreover, with an inefficient regulation the agent might employ an inefficient reporting and disclosure procedure.     

Social Security with Heterogeneous Populations Subject to Demographic Shocks

In a previous paper, we showed how a pay-as-you-go social security scheme, based on voluntary contributions, can be an appropriate institution to reach an optimal sharing of risks among generations in the presence of demographic uncertainties. We study here the functioning of such schemes when there are different population strata, with different demographic shocks and wages. We show that while a collective voluntary pay-as-you-go scheme can provide efficient intergenerational risk sharing, it is likely to be destabilized by pensions funds specialized by agents' types. This is true both when there is a complete set of contingent markets, where the risk pooling capabilities of a collective fund are potentially of less interest, and when markets are incomplete. In this last circumstance, a collective fund may help the living agents to share their intragenerational risks. However, we show that the resulting allocation does not Pareto dominate the outcome of individual funds by agent types, and that there are incentives for agents to separate from any collective organization.     

Nonmonetary asset exchanges revisited: An updated pedagogical approach

This paper reviews current GAAP for nonmonetary asset exchanges, presents a pedagogical approach that instructors and textbook authors can use to clarify their coverage of this topic, and highlights intermediate accounting textbooks that provide complete, accurate coverage of this topic.