Strevens's mechanism transforms a resource-based reward scheme (Marge) into an achievement-based (Goal) then priority-only (Priority) scheme, with risk aversion shifting labor toward higher-potential programs

philosophy-of-sciencepriority-rulemichael-strevensmechanism-designrisk-aversiondivision-of-cognitive-laborresource-allocation

Strevens's economic account of the priority rule runs on a named sequence of three reward schemes, each a transformation of the last:

1. Marge — a resource-based scheme paying every scientist in proportion to their marginal contribution to their program's probability of success, regardless of whether the program succeeds. Strevens proves (section 3) that Marge produces the optimal allocation of labor in the additive case, given decreasing marginal returns on invested labor: "there is a reward system, the Marge scheme, that will ensure an optimal allocation of labor among any set of research programs, provided that the programs have goals with additive values and yield decreasing marginal returns on investment."
2. Goal — Marge converted to an achievement-based scheme: "First, Marge's resource-based scheme is transformed into an achievement-based scheme on which scientists are rewarded only if their program achieves its goal." The expected reward under Goal equals that under Marge, so the shift matters only because scientists are risk-averse: facing two programs of equal expected reward but unequal win-probability, "A risk averse scientist will therefore choose the higher-potential program." Decreasing marginal utility of prestige is the specific psychological gear.
3. Priority — Goal restricted so that in a tie only the first is paid: "The second step of the transformation turns Goal into a scheme in which there is a priority race, so that, if two rival programs both achieve their goal, only the first to do so is rewarded. I call the resulting scheme the Priority reward scheme." This sharpens the bias further, because the risk of losing a priority race despite succeeding falls harder on lower-potential programs, pushing risk-averse scientists in weaker programs toward stronger ones.

Each step is argued to bias allocation progressively toward the higher-potential program — the direction the winner-confers-all optimum requires. Crucially, that this bias reaches the true optimum is not claimed; see claim-strevens-does-not-prove-priority-optimal-in-winner-confers-all. The scheme belongs to the vault's credit-assignment cluster and stands as an economic rival to Merton's norm-enforcement account.