We study how relational contracts mitigate Becker's classic problem of providing general human capital when training contracts are incomplete. The firm's profit-maximizing agreement is a multiperiod apprenticeship in which the novice is trained gradually over time and eventually receives all knowledge. The firm adopts a 1/e rule, whereby at the beginning of the relationship the novice is trained, for free, just enough to produce a fraction 1/e of the efficient output. After that, the novice earns all additional knowledge with labor. This rule causes inefficiently lengthy relationships that grow longer the more patient the players. A minimum wage is welfare enhancing.

A principal specifies time paths of effort provision, task allocation, and knowledge transfer for a cash-constrained apprentice, who is free to walk away at any time. In the optimal contract the apprentice pays for training by working for low or no wages and by working inefficiently hard. The apprentice can work on both knowledge-complementary and knowledge-independent tasks. We study the optimal time path of effort distortions and their impact on the knowledge transfer, and analyze the effect of regulatory limits on the length of apprenticeships and on how much effort apprentices are allowed to provide.