An Investigation of Policy Administrative Costs Using Panel Data for the English Environmentally Sensitive Areas

This paper explores transactions costs in the context of agri‐environmental policy schemes based on management agreements. While transactions costs encompass a wide range of organisational costs, the focus here is on the public‐sector administrative costs of policy implementation. Empirical administrative cost functions were estimated to investigate the factors affecting the magnitude of such costs, using panel data spanning five years for the 22 English Environmentally Sensitive Areas. The extent of participation appears to be important in explaining administrative cost variability across areas. The data suggested the existence of size economics with regard to the numbers of agreements made in any one ESA, and a significant effect of scheme experience in exerting downwards‐pressure on administrative costs. Policy budgeting and evaluation should take into account the non‐trivial costs of organisation, particularly if agri‐environmental schemes based on the procurement of conservation goods through management agreements are to be extended in future.     

Participating Insurance Contracts and the Rothschild-Stiglitz Equilibrium Puzzle

We extend the Rothschild-Stiglitz (RS) insurance market model with adverse selection by allowing insurers to offer either non-participating or participating policies, that is, insurance contracts with policy dividends or supplementary calls for premium. It is shown that an equilibrium always exists in such a setting. Participating policies act as an implicit threat that dissuades deviant insurers who aim to attract low-risk individuals only. The model predicts that the mutual corporate form should be prevalent in insurance markets where second-best Pareto efficiency requires cross-subsidisation between risk types.     

Solvable local and stochastic volatility models: supersymmetric methods in option pricing

In this paper we provide an extensive classification of one- and two-dimensional diffusion processes which admit an exact solution to the Kolmogorov (and hence Black–Scholes) equation (in terms of hypergeometric functions). By identifying the one-dimensional solvable processes with the class of integrable superpotentials introduced recently in supersymmetric quantum mechanics, we obtain new analytical solutions. In particular, by applying supersymmetric transformations on a known solvable diffusion process (such as the Natanzon process for which the solution is given by a hypergeometric function), we obtain a hierarchy of new solutions. These solutions are given by a sum of hypergeometric functions, generalizing the results obtained in a paper by Albanese et al. (Albanese, C., Campolieti, G., Carr, P. and Lipton, A., Black–Scholes goes hypergeometric. Risk Mag., 2001, 14, 99–103). For two-dimensional processes, more precisely stochastic volatility models, the classification is achieved for a specific class called gauge-free models including the Heston model, the 3?/?2-model and the geometric Brownian model. We then present a new exact stochastic volatility model belonging to this class.     

Portfolio optimization under model uncertainty and BSDE games

We consider robust optimal portfolio problems for markets modeled by (possibly non-Markovian) Itô–Lévy processes. Mathematically, the situation can be described as a stochastic differential game, where one of the players (the agent) is trying to find the portfolio that maximizes the utility of her terminal wealth, while the other player (“the market”) is controlling some of the unknown parameters of the market (e.g., the underlying probability measure, representing a model uncertainty problem) and is trying to minimize this maximal utility of the agent. This leads to a worst case scenario control problem for the agent. In the Markovian case, such problems can be studied using the Hamilton–Jacobi–Bellman–Isaacs (HJBI) equation, but these methods do not work in the non-Markovian case. We approach the problem by transforming it into a stochastic differential game for backward stochastic differential equations (a BSDE game). Using comparison theorems for BSDEs with jumps we arrive at criteria for the solution of such games in the form of a kind of non-Markovian analogue of the HJBI equation. The results are illustrated by examples.     

Application de la théorie collective du risque à la réassurance « Excess-Loss »

Abstract

Introduction.

Les méthodes de calcul de la prime de réassurance Excess-Loss utilisées jusqu'à présent ou bien avaient un caractère purement empirique, ou bien présumaient que les écarts entre le montant des sinistres constatés et le montant des sinistres attendus se répartissent suivant la loi de Laplace-Gauss.     

International portfolio diversification: Currency,industry and country effects revisited

We examine the relative importance of country, industry, world market and currency risk factors for international stock returns. Our approach focuses on testing the mean-variance efficiency of the various factor portfolios. An unconditional analysis does not show significant differences between country, industry and world portfolios, nor any role for currency risk factors. However, when we allow expected returns, volatilities and correlations to vary over time, we find that equity returns are mainly driven by global industry and currency risk factors. We propose a novel test to evaluate the relative benefits of alternative investment strategies and find that including currencies is critical to take full advantage of the diversification benefits afforded by international markets.     

The Displacement Effect of Public Pensions on the Accumulation of Financial Assets*

The generosity of public pensions may depress private savings and provide incentives to retire early. While there is plenty of evidence supporting the latter effect, there remains considerable controversy over whether public pensions crowd out private savings. This paper uses international micro‐data sets collected over recent years to investigate whether public pensions displace private savings. The identification strategy relies not only on cross‐country differences in generosity but also on differences in the progressivity or non‐linearity of pension formulas across countries. We estimate that an extra dollar of pension wealth depresses accumulated financial assets around the time of retirement by 22 cents. An extra 10,000 dollars in public pension wealth reduces the average retirement age by roughly one month, which implies an elasticity of years of retirement with respect to pension wealth of 0.15.