90) has shown that options contracts can mitigate the problem of hold-up (a problem of underinvestment that arises when the exact amount of the investment cannot be contractually determined).  In contract theory, however, there is debate about whether option contracts still make sense if the parties cannot rule out future renegotiations.  As von Tirole (1999) pointed out, this debate is at the heart of discussions on the foundations of the theory of incomplete treaties.  In a laboratory experiment, Hoppe and Schmitz (2011) confirmed that non-negotiable option contracts can actually solve the hold-up problem.  Moreover, it turns out that option contracts still make sense even if renegotiations cannot be excluded […].