Samenvatting

Ex post evaluation is important for various reasons, in particular also from the perspective of parliaments. Evaluations feed and deepen the democratic debate by adding evidence on the results and real world impacts of laws. This strengthens each of the three institutional tasks of parliaments (initiating and approving laws, supervising government and approving the budget). Yet few parliaments in OECD countries have deployed ex post evaluation systematically.
While the rationale for ex post evaluation is broadly understood, initiatives often run into political logics. The role that parliaments play also differs greatly between countries. There is no clear best practice. Ambition, tradition, culture, political will, capacity and resources determine what is possible and desirable. A positive trend is however noticeable.
Building on examples and experiences in several parliaments, we make some recommendations to upgrade ex post evaluation practice within Parliaments. We elaborate on the Flanders’ case, where the Parliament is looking for mechanisms to extend its role in ex post evaluation. We recommend i.a. the introduction of an annual momentum on which the results of Government policies can be discussed and the performance of a number of ex post evaluations by the Parliament following the example of the French system of ‘rapports d’information’.