The EMB was devised as a vehicle for Britain to reciprocate, by means of a non-tariff preference, the tariff preferences that its exports enjoyed in Dominion markets ( Drummond 1974, p. Yet, apart from a few deviations, Britain clung to its longstanding policy of free trade, which precluded any reciprocation in the form of preferential tariffs. In the 1920s, the tariff-autonomous Dominions and colonies extended preferential tariffs to imports from Britain ( MacDougall and Hutt 1954, p. It was conceived as a solution to an impasse in the political economy of the British empire. The Empire Marketing Board (EMB) was a relatively transient feature of the interwar British economy, operating from just 1926–33.