Semitractability of optimal stopping problems via a weighted stochastic mesh algorithm

In this paper, we propose a Weighted Stochastic Mesh (WSM) algorithm for approximating the value of discrete‐ and continuous‐time optimal stopping problems. In this context, we consider tractability of such problems via a useful notion of semitractability and the introduction of a tractability index for a particular numerical solution algorithm. It is shown that in the discrete‐time case the WSM algorithm leads to semitractability of the corresponding optimal stopping problem in the sense that its complexity is bounded in order by with being the dimension of the underlying Markov chain. Furthermore, we study the WSM approach in the context of continuous‐time optimal stopping problems and derive the corresponding complexity bounds. Although we cannot prove semitractability in this case, our bounds turn out to be the tightest ones among the complexity bounds known in the literature. We illustrate our theoretical findings by a numerical example.     

Finance and growth in Africa: The broken link

While bank liabilities in Sub-Saharan Africa are found to follow (but not lead) economic growth, the link between bank credit and growth is altogether absent.     

Allocative efficiency measurement with endogenous prices

In the nonparametric measurement of allocative efficiency, output prices are fixed. If prices are endogenous, the overall output in the market determines the allocative efficient point. We develop an alternative semi-nonparametric model that allows prices to be endogenously determined.     

On structural inelasticity of modal substitution in freight transport

At the European level there is an increasing focus on how freight transport can be moved from trucks on roads to more environmentally friendly modes such as rail and ship. A large proportion of the transport services between OD pairs, however, cannot be substituted since there is only one alternative available. The paper investigates the magnitude of this “structural inelasticity” of modal substitution in freight transport due to a sparser layout of rail and ship-based freight networks compared to road. In the analysis we use a recent Scandinavian freight demand model covering more than 800 zones. We find that the structural inelasticity is very significant - in particular for transportation over less than 500 km. Moreover, the inelasticity varies greatly with commodity groups and between OD pairs, and it depends strongly on the port and rail infrastructure. The results suggest that pure charging instruments (road pricing for trucks) in many regions will have limited mode substitution impacts. However, if combined with structural changes in terms of improved infrastructure for rail and ship, impacts may be greater.     

Why do employees keep choosing the high-premium health care plan? An investigation of the financial consequences and logic of employee health care plan selections

In 1991, Dannon employees had the choice to stay with their current health care plan or switch to a new plan which offered a lower premium and less hospital cost coverage that better fit the needs of most employees. Both plans were the same in all other respects. Only 25% of employees chose the new lower-premium plan over the old plan. This article reports a collaborative effort between The Dannon Company and Cornell University's Center for Advanced HR Studies to identify the patterns of employee choices, and the effects of those choices on the actual costs that employees incurred. The actual decisions of 287 Dannon employees were examined, and the out-of-pocket costs that they actually incurred in the two years after the plan was introduced were calculated. © 1996 by John Wiley & Sons, Inc.     

The impact of the internet upon fundraising

Through research on a sample of the top 2000 charities, the Voluntary Organisations Internet Server (VOIS) revealed the potential for a major initiative to provide the opportunity for voluntary organisations to create a quality brand of information on the Internet by coming together on a collective site. The Internet is an ideal medium for voluntary organisations to get their message across, build relationships and raise funds. VOIS has been designed specifically to facilitate these activities and provide the means to a collective presence. While it is mainly large organisations that are using it at the moment, the Internet represents the opportunity for smaller organisations to have a substantial presence because of its democratic nature. VOIS has utilised the principle of economies of scale in order that all organisations can afford to have a useful presence on the Internet. This paper will examine fundraising activities that are already occurring on the Internet, analyse the strengths of the Internet as a marketing tool, explain how marketers can utilise these strengths and explain how VOIS has tried to facilitate these strengths within the features of its standardised site.