Precommitment vs. Commitment Device: They're Not the Same Layer

Precommitment is the strategy. A commitment device is one implementation of it. Treating them as interchangeable is like treating “authentication” and “a password field” as the same thing — one names a goal, the other names a specific mechanism for reaching it.

Precommitment, as economist Thomas Schelling framed it in The Strategy of Conflict (1960), is the strategy of deliberately narrowing your own future options to guarantee an outcome, before your future self gets a vote. Schelling built the concept for game theory and deterrence — a party strengthens its position by visibly removing its own ability to back down. He later applied the same logic inward, to a person negotiating with their own future self across time, the branch behavioral economics picked up.

A commitment device is any specific tool that implements precommitment — see the working definition — a locked savings account, an escalating pledge, a friend who confirms you did the thing. It’s the password field, not authentication itself. The Ulysses contract is the literal case: a device modeled directly on Schelling’s own illustration.

Keep the layers separate for debugging purposes: a bad commitment device — a penalty nobody enforces, a witness who never checks — doesn’t disprove precommitment as a strategy. It means that one implementation failed to restrict the option it claimed to restrict.