The delta-function-kicked rotor: Momentum diffusion and the quantum-classical boundary

We investigate the quantum-classical transition in the delta-kicked rotor and the attainment of the classical limit in terms of measurement-induced state-localization. It is possible to study the transition by fixing the environmentally induced disturbance at a sufficiently small value, and examining the dynamics as the system is made more macroscopic. When the system action is relatively small, the dynamics is quantum mechanical and when the system action is sufficiently large there is a transition to classical behavior. The dynamics of the rotor in the region of transition, characterized by the late-time momentum diffusion coefficient, can be strikingly different from both the purely quantum and classical results. Remarkably, the early time diffusive behavior of the quantum system, even when different from its classical counterpart, is stabilized by the continuous measurement process. This shows that such measurements can succeed in extracting essentially quantum effects. The transition regime studied in this paper is accessible in ongoing experiments.Comment: 8 pages, 4 figures, revtex4 (revised version contains much more introductory material

Non-risk price discrimination in insurance: market outcomes and public policy

This paper considers price discrimination in insurance, defined as systematic price variations based on individual customer data but unrelated to those customers’ expected losses or other marginal costs (sometimes characterised as “price optimisation”). An analysis is given of one type of price discrimination, “inertia pricing,” where renewal prices are higher than prices for risk-equivalent new customers. The analysis suggests that the practice intensifies competition, leading to lower aggregate industry profits; customers in aggregate pay lower prices, but not all customers are better off; and the high level of switching between insurers is inefficient for society as a whole. Other forms of price discrimination may be more likely to increase aggregate industry profits. Some public policy issues relating to price discrimination in insurance are outlined, and possible policy responses by regulators are considered. It is suggested that competition will tend to lead to increased price discrimination over time, and that this may undermine public acceptance of traditional justifications for risk-related pricing

Insuring large-scale floods in the Netherlands

Without its primary flood defenses, a large part of the Netherlands would be swallowed by rivers and the sea. Floods caused by the failure of primary flood defenses are high-impact, low-probability events that are notoriously difficult to insure. Private insurance was long considered unfeasible but the Dutch government is currently studying ways to introduce a public–private insurance program. This paper offers a discussion of variables that should be taken into account in the choice for an arrangement for the financing of large-scale floods in the Netherlands. Because flood risk is highly concentrated and potential losses could be severe, a strong government role seems inevitable. But this would not necessarily be inappropriate as this could reduce the risk of underinvestment in flood protection. The Geneva Papers (2008) 33, 250–268. doi:10.1057/gpp.2008.10