  Using a lab experiment, we investigate the real-life performance of envy-free
and proportional cake-cutting procedures with respect to fairness and
preference manipulation. We find that envy-free procedures, in particular
Selfridge-Conway, are fairer and also are perceived as fairer than their
proportional counterparts, despite the fact that agents very often manipulate
them. Our results support the practical use of the celebrated Selfridge-Conway
procedure, and more generally, of envy-free cake-cutting mechanisms.
  We also find that subjects learn their opponents' preferences after repeated
interaction and use this knowledge to improve their allocated share of the
cake. Learning reduces truth-telling behavior, but also reduces envy.
