We introduce and study a game-theoretic model to understand the spread of an epidemic in a homogeneous population. A discrete-time stochastic process is considered where, in each epoch, first, a randomly chosen agent updates their action trying to maximize a proposed utility function, and then agents who have viral exposures beyond their immunity get infected. Our main results discuss asymptotic limiting distributions of both the cardinality of the subset of infected agents and the action profile, considered under various values of two parameters (initial action and immunity profile). We also show that the theoretical distributions are almost always achieved in the first few epochs.

The market failures approach (MFA) to business ethics argues that economic theory regarding the efficient workings of a market can generate normative prescriptions for managerial behaviour. It argues that actions that inhibit Pareto optimal solutions are immoral. However, the approach fails to identify goods that should be regulated or prohibited from the market, something common to the moral limits to markets (MLM) approach to business ethics. There are, however, numerous assumptions underlying Paretian efficiency, including some about the preferences of market participants. Trade in some goods violates some of these assumptions, and so these goods are morally suspect and can be understood to indicate that the market for these goods is not moral. This creates grounds sufficient for regulating, and possibly prohibiting, these goods. To help determine whether it is then necessary to regulate the goods, I propose a supplementary economic analysis to ascertain why an assumption regarding a particular preference is being violated.

Defined contribution (DC) pension plans have been gaining ground in the last 10–20 years as the preferred system for many countries and other agencies, both private and public. The central question for a DC plan is how to invest in order to reach the participant's retirement goals. Given the financial illiteracy of the general population, it is common to offer a default policy for members who do not actively make investment choices. Using data from the Chilean system, we discuss an investment model with fixed contribution rates and compare the results with the existing default policy under multiple objectives. Our results indicate that the Chilean default policy has good overall performance, but specific closed-loop policies have a higher probability of achieving desired retirement goals and can reduce the expected shortfall at retirement.

Those with responsibility for the assets of institutional investors have a fiduciary duty to attempt to earn the best possible risk adjusted returns and to comply with ethical standards. A satisfactory resolution of these, and other, conflicting demands requires a coherent intellectual framework. Such a framework can be based on a traditional scheme that analyses the various components of profit in terms of the requirements of justice. The framework provides a basis for discussing the major challenges facing the institutional investors. These relate to their role in rational asset selection, effective corporate governance, job creation and the minimisation of environmental impact.

Foliations provide a general, convenient, geometric way to catalogue information from topics as varied as sufficient statistics, solutions of differential equations, indifference curves for utility functions, distributed computing, and so forth. An introduction to aspects of this area is provided.

A premium calculation principle π is called positively homogeneous if π(cX) = cπ(X) for all c > 0 and all random variables X. For all known principles it is shown that this condition is fulfilled if it is satisfied for two specific values of c only, say c = 2 and c = 3, and for only all two point random variables X. In the case of the Esscher principle one value of c suffices. In short this means that local homogeneity implies global homogeneity. From this it follows that in the case of the zero utility principle or Swiss premium calculation principle, the underlying utility function is of a very specific type.

A very general theorem on premium calculation principles which satisfy a weak continuity condition, is added. Among others the proof uses Kroneckers Theorem on Diophantine Approximations.