In economics, the hold-up problem is central to the theory of incomplete contracts, and shows the difficulty in writing complete contracts. A hold-up problem arises when two factors are present: 1. * Parties to a future transaction must make noncontractible relationship-specific investments before the transaction takes place. 2. * The specific form of the optimal transaction (such as quality-level specifications, time of delivery, what quantity of units) cannot be determined with certainty beforehand.