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...

I apply a survival model to a detailed dataset of Swedish patents to estimate how different factors affect the likelihood of patent renewal. Since the owners know more about the patents than potential external financiers, there is a problem of asymmetric information. To overcome this, Sweden has...