When a group of politicians enters office, there is no choice: the inherited commitments of past government must be accepted as givens. The legacy that they inherit is carried forward by institutional commitments grounded in laws, organizations and budgets that are more important than the preferences of individuals. This paper first explains why this is so. The extent to which public policies are durable, that is, persisting from one administration or one decade to another, is tested in the second section, using public expenditure data for hundreds of programmes of British government over a period of 40 years since the end of the Second World War. The third section tests whether the introduction or termination of programmes tends to reflect party differences, changes in the economic climate, or differences between social programmes integral to the individual life-cycle as against those responding to market conditions. The conclusion shows how changes can occur as the unforeseeable consequences of programme commitments entered into in the distant past, and carried forward by political inertia. The result of this legacy is change without choice.
