The authors conducted a field experiment using experimental economists as subjects. They sent letters to economists who submitted papers to the Economic Science Association 2006 meeting in Nottingham. One sentence was varied in the letter to vary between (1) discount- and (2) penalty-framings.“We take this opportunity to remind you that [(1) the discounted conference fee for early registration is available until/ (2)the conference fee will include a penalty for late registration after]10 July 2006.”They find that while the behaviour of junior experimental economists is affected by the framing, the senior members of the subject pool are unaffected.