High frequency financial data allows us to learn more about volatility, volatility of volatility and jumps.  One of the key techniques developed in the literature in recent years has been bipower variation and its multipower extension, which estimates time-varying volatility robustly to...

We consider three 'cases studies' of the uses and mis-uses of mathematics in economics and econometrics.  The first concerns economic forecasting, where a mathematical analysis is essential, and is independent of the specific forecasting model and how the process being forecast behaves.  The...

Almost no economic time series is either weakly or strictly stationary: distributions of economic variables shift over time.  Thus, the present treatment of expectations in economic theories of inter-temporal optimization is inappropriate.  It cannot be proved that conditional expectations...

This paper examines the relationship between norm enforcement and in-group favouritism behaviour.  Using a new two-stage allocation experiment with punishments, we investigate whether in-group favouritism is considered as a social norm in itself or as a violation of a different norm, such as...

We study in-group favouritism and out-group discrimination in a multiplayer dictator game.  An allocator divides a large sum of money among three groups of 20 recipients each and Self.  Allocations to groups are divided equally among the group members.  The three groups are supporters of the...

Individual behaviors such as smoking, fashion, and the adoption of new products is influenced by taking account of others' actions in one's decisions.  We study social influence in a heterogeneous population and analyze the long-run behavior of the dynamics.  We distinguish between cases in...

Using a laboratory experiment with minimal groups, we examined the extent to which the threats of costly punishments affect in-group favouritism behaviour. We studied three types of punishment separately: in-group, out-group, and third-party punishments. In line with previous studies, the...

Can we devise mechanisms that allow voters to express the intensity of their preferences when monetary transfers are forbidden? Would we then be able to take account of how much voters wish the approval or dismissal of any particular issue? In such cases, would some minorities be able to decide...

Jackson and Sonnenschein (2006) show that by linking collective decisions the incentive costs can become negligible and, at the limit, ex-ante efficiency can be achieved. In a voting situation this implies that the agents` intensity of preferences can be taken into account even in the absence of...