In environments with expected utility, it has long been established that speculative trade cannot occur (Milgrom and Stokey), and that the value of public information is negative in economies with risk-sharing and no aggregate uncertainty (Hirshleifer, Schlee). We show that these results are...

The COVID-19 pandemic has resulted in high fatality rates and widespread lockdowns, that countries aim to ease by deploying contact-tracing mobile apps, which notify individuals who were in close geographical proximity to positive cases. We suggest that a powerful tool to induce social...

We show that there cannot be common knowledge trade in a truly decentralised environment, such as in a blockchain. A trade is an agreement to buy and sell a security that pays according to some state of nature; it is settled when the security's value is verified by an oracle, an intermediary who...

We provide a syntactic model of unawareness. By introducing multiple knowledge modalities, one for each sub-language, we specifically model agents whose only mistake in reasoning (other than their unawareness) is to underestimate the knowledge of more aware agents. We show that the model is a...

We report results from a sender-receiver deception game, which tests whether an individual's decision to deceive is influenced by a concern for relative standing in a reference group. The sender ranks six possible outcomes, each specifying a payoff for him and the receiver. A message is then...