This work splits effective unemployment into two components: The natural unemployment, and the cyclical unemployment. For that purpose, an estimation of stochastic cost frontier is performed. The study is focused on the 17 autonomous communities in Spain over the period 1982-2012. Results evidence a greater importance of the natural component as the principal determinant of effective unemployment. When comparing these results with those obtained applying univariate filters, the distribution in the components of the effective unemployment changes, increasing the importance of cyclical unemployment. This result indicates that the policymakers have a greater margin of action to implement aggregate demand policies.