Mixed‐strategy Nash equilibrium is the cornerstone of our understanding of strategic situations that require decision makers to be unpredictable. Using data from nearly half a million serves over 3000 tennis matches, and data on player rankings from the ATP and WTA, we examine whether the...

We run a public good experiment in the field and in the lab with (partly) the same subjects. The field experiment is a true natural field experiment as subjects do not know that they are exposed to an experimental variation. We can show that subjects' behavior in the classic lab public good...