One of the major reasons why inventors are awarded patents by governments is they encourage R&D investments and commercialization of inventions. If the patent holder commercializes his invention, he has stronger incentives to retain the patent. The purpose here is to empirically analyze the...

In medieval Europe, old coins were frequently declared invalid and exchanged for new ones at fixed rates and dates. Here, the question of whether and when such re-coinage was applied in medieval Sweden is analyzed against the historical record. A theory of how short-lived coinage systems work is...