A Nonlinear Model of the Term Structure of Interest Rates

We present an economically motivated two–factor term structure model that generalizes existing stochastic mean term structure models. By allowing a certain parameter to acquire dynamical behavior we extend the two–factor model to obtain a nonlinear three–factor model that is shown, in a deterministic version, to be equivalent to the Lorenz system of differential equations. With reasonable parameter values the model exhibits chaotic behavior. It successfully emulates certain properties of interest rates including cyclical behavior on a business cycle time scale. Estimation and pricing issues are discussed. Standard PCA techniques used to estimate HJM type models are observed to be equivalent to dimensional estimates commonly applied to 'spatial data' in nonlinear systems analysis.
It is concluded that techniques commonly used in the analysis of nonlinear systems may be directly applicable to interest rate models, offering new insights in the development of these models. Tests of nonlinearity in interest rate behavior may need to focus on long cycle times.     

Mapping and analysing virtual outcrops

Laser scanning is a very efficient way to generate realistic, high-resolution digital models of 3-D geological outcrops. This paper discusses the methodologies involved in the creation and analysis of virtual outcrops, based on laser scanner data. The visualisation of the laser scanner data as a photorealistic 3-D object is described. Geological features picked out on the virtual outcrop (e.g. fractures, faults or bedding planes) can be extrapolated outward, into space, and inward, into the subsurface, using tension surfaces.     

An Experimental Study of Statistical Discrimination by Employers

This article reports findings of an experiment motivated by a dynamic labor market model that considers the problem faced by employers in making hiring decisions between workers of different types. The question examined here is how quickly employers learn about the ability of a group of workers through observing representatives of that group. If prior opinions are weak, the employer will use Information from the workplace to quickly update any incorrect group-based stereotypes it may have. On the other hand, if priors are heavily weighted, incorrect initial perceptions will result in persistent wage differences. Our experimental findings are twofold. First, subjects' (employers') behavior moves quickly toward optimal choices. Second, strong priors are hard to establish. These results suggest that it would take a long time for employers to form group-based stereotypes and that such stereotypes should go away quickly in response to signals that contradict these stereotypes.     

Local water markets for irrigation in southern Spain: A multicriteria approach

Spanish authorities have recently approved a new legislative framework for the creation of local water markets to improve allocative efficiency for this scarce resource. This paper analyses the potential impacts of the policy. A utility function for three groups of farmers was elicited, using a method that does not require interaction with the decision-makers. Utility was measured as a function of the first two moments of the distribution of total gross margin. The utility functions were then used to simulate farmers' responses to changes in the price of water.     

government and the PSBR

The government has changed its view of how to gauge the size of the budget deficit. Nick Parsons and David Coleman, of Union Discount, argue that this change is an ill-omen for the control of public spending.     

保险业要么锁定客户，要么收购

贝恩公司调查发现,仅有1／10的保险公司成功地实现连年持续地创造价值。许多公司最终表现欠佳的主要原因在于,他们严重误判自己提供客户所需产品／服务的能力。当高级主管被问及是否认为本公司提供最佳客户体验时,77％的高管自认为是,但仅有6％的客户认同。那么,究竟什么才是保险业实现最佳股东回报的关键呢?