In this paper we make the following three claims. (1), in contradiction with the conventional view according to which the French depression was very different to that observed in the US, we argue that there are more similarities than differences between the French and U.S. experiences and therefore a common explanation should be sought. (2), poor growth in technological opportunities appear neither necessary nor sufficient to account for the French depression. (3), changes in institutional and market regulation appear necessary to account for the overall changes observed over the period. Moreover, we show that the size of these institutional changes may by themselves be enough to quantatively explain the French depression. However, at this time, we have no theory to explain the size or the timing of these changes.