A standard argument is that British agriculture must be protected in order to reduce the scarcity of world food supplies. The small average size of British farms is often advanced as a reason for their inefficiency which, it is claimed, is due to an under-utilization of costly capital equipment and, to some extent, of labour on the small farm. The basic problem of British agricultural policy, therefore, is to speed up the rate of technical progress and to ensure that those who become farmers are the most capable of applying it. The political organization of farmers' interests has led to many wasted opportunities of fostering technical improvement. The difficulty is to reconcile a competitive market for British agriculture with the aim of maintaining the proportion of the country's population engaged in the industry. Many substantial changes are required in the agricultural legislation, especially that deriving from the Agriculture Acts of 1947–9.