David uses the persistence of the QWERTY keyboard to formulate path dependence as a challenge to equilibrium models of technological choice. The essay’s iconic idea is that historically contingent sequences can lock systems into arrangements that are neither uniquely rational nor technically optimal. Small initial events become consequential when learning effects, coordination requirements and sunk investments reinforce a particular standard. Methodologically, David treats history as an explanatory force rather than noise to be eliminated from economic analysis. The work builds a bridge between economics, technology studies and institutional theory by showing that infrastructures acquire durability through interdependence. Once users, machines, training systems and markets are coordinated around a format, changing one component becomes prohibitively difficult. QWERTY therefore becomes less a story about keyboards than a model of how conventions harden into environments. The essay offers a precise account of why obsolete or compromised systems survive: not because every participant prefers them, but because collective dependency makes alternatives difficult to inhabit.