The change in the relationship between unemployment and vacancies in Great Britain has produced different explanations. The difference boils down to whether there has been a shift in labour demand or supply. This paper specifies the "labour supply" hypothesis so that its plausibility can be tested using prediction tests and Chow tests. The conclusion is that the effect of improved unemployment benefits on median unemployment duration and numbers unemployed was minimal. Any shift in the supply side can best be accounted for by an increase in the demand for leisure arising from increased affluence.