In finance, decision making and choice requires that we assume that asset prices tend to trend. This assumption also logically enables us to construct exits to limit losses and protect capital. But investors have good reason to be uneasy regarding the potential for significant loss when using a...

Traditional portfolio optimization models specify placement of capital as rather irrevocably and fully at risk through investment horizon(s) or continuously. Under this constraint, asset class allocation typically serves as primary mode of diversification, pursuing risk moderation by seeking to...

We consider cooperative games with transferable utility (TU-games), in which we allow for a social structure on the set of players. The social structure is utilized to refine the core of the game. For every coalition the relative strength of a player within that coalition is induced by the...

Until recently, theorists considering the evolution of human cooperation have paid little attention to institutional punishment, a defining feature of large-scale human societies. Compared to individually-administered punishment, institutional punishment offers a unique potential advantage: the...

The emergence and survival of cooperation is one of the hardest problems still open in science. Several factors such as the existence of punishment, repeated interactions, topological effects and the formation of prestige may all contribute to explain the counter-intuitive prevalence of...

Present market instabilities have prompted great interest on the characteristics of specific portfolios such as minimum variance and equally- weighted risk contribution portfolios as these portfolios do not rely on the estimate of expected returns. Indeed, in turmoil periods traditional market...

Volatility is usually considered as a synonym for risk. Mainstream financial theory states that higher portfolio volatility is translated into higher expected returns while diversification helps eliminate idiosyncratic risks. This leaves us with an apparent anomaly as low-risk (low-beta) stocks...

We present a simple example where the use of sigma-algebras as a model of information leads to a paradoxical conclusion: a decision maker prefers less information to more. We then explain that the problem arises because the use of sigma-algebras as the informational content of a signal is...

Until recently, theorists considering the evolution of human cooperation have paid little attention to institutional punishment, a defining feature of large-scale human societies. Compared to individually administered punishment, institutional punishment offers a unique potential advantage: the...