  This paper examines signalling when the sender exerts effort and receives
benefits over time. Receivers only observe a noisy public signal about the
effort, which has no intrinsic value.
  The modelling of signalling in a dynamic context gives rise to novel
equilibrium outcomes. In some equilibria, a sender with a higher cost of effort
exerts strictly more effort than his low-cost counterpart. The low-cost type
can compensate later for initial low effort, but this is not worthwhile for a
high-cost type. The interpretation of a given signal switches endogenously over
time, depending on which type the receivers expect to send it.
  JEL classification: D82, D83, C73.
  Keywords: Dynamic games, signalling , incomplete information
