Pricing inputs to induce efficient Make-or-Buy decisions

We investigate input pricing regimes that induce efficient Make-or-Buy decisions by entrants when there is constant returns in the production of the input(s) and simultaneous noncooperative price competition in downstream retail markets. Necessary and sufficient conditions for efficient Make-or-Buy decisions are derived. The necessary condition shows that input prices are relevant for Make-or-Buy decisions except under restrictive and often unverifiable assumptions on the demand structure, and that the least informationally-demanding way to ensure efficient Make-or-Buy decisions is to price inputs at marginal cost provided changes in the entrant's cost have a "normal" effect on the entrant's profit. The conditions also show that pricing the incumbent's input at the entrant's marginal cost always ensures efficient Make- or-Buy decisions. The extent to which input prices can depart from marginal cost while still inducing efficient Make-or-Buy decisions increases with the efficiency differential between the incumbent and entrant and with the demand displacement ratio.