In microeconomics, a credence good is any purchase where the consumer cannot assess the marginal utility of the service even after paying for it. The classic textbook example is an automotive repair shop. If a mechanic replaces an alternator and the car starts, you know the outcome is acceptable. You have no way of knowing whether the car actually required a new alternator or a loose ground wire tightened with a quarter turn of a wrench. The information asymmetry belongs entirely to the seller.

Over the past year, frontier foundation model providers have packaged inference compute into the exact same economic structure. Instead of selling raw text completion, labs offer reasoning models equipped with an ordinal dial: low, medium, high, and maximum effort. The marketing premise sounds straightforward. If a problem is easy, the system answers quickly. If a problem requires multi-step deduction or complex tool orchestration, the user turns the dial to allocate additional test-time computation.…