It is well known that the first welfare theorem can fail foroverlapping generations economies with private production andunsecured debt. This paper demonstrates that the reason for thisfailure is that intermediation is modeled as a purely passivecoordination activity implemented by a Walrasian Auctioneer. Whenintermediation is modeled instead as a contestable activity carriedout by a corporate intermediary owned by consumer-shareholders andoperated in their interest, every equilibrium is Pareto efficient.In broader terms, these findings caution that the inefficiency observed in standard modelings of overlapping generations economiesmay not be the reflection of an intrinsic market failure. Rather,the observed inefficiency could instead be due to a fundamentalincompleteness in the model specification — the presumed inability ofprivate agents to exploit the earnings opportunities associated with incurring and forever rolling over debt.