This article describes a positive model of the implementation of policy decisions. The model combines the salience of implementation agencies for policy decisions with the extent to which these agencies are effectively controlled, in order to predict agency deviations from policy decisions. Special attention is paid to the effects of (a lack of) political consensus on the amount of agency deviations. Political consensus does not generally enhance compliance - as is often asserted - but does so conditional upon a low agency salience. This is shown both in a theoretical analysis and by an application of the model on the implementation of 17 policy decisions in a Dutch municipality.