This paper shows how matching problems reduce employment – and hence also raise unemployment – by creating a gap between labour demand and employment. It also shows how this gap can be measured by unfilled jobs (unmet demand) as distinct from job vacancies (recruitment processes) and reports results from a vacancy survey which measures both. In fact, while a shift of the matching function indicating longer recruitment times suggests increasing matching problems, it is only the measurement of unfilled jobs which can verify this and at the same time quantify the effect on unemployment.