Difference-in-Differences method for policy evaluation

Out of the many projects financed by the European Union, some are more effective than others. Choosing the most effective ones is important to give good value for money for the European taxpayers. The EU also oversees regulations that aim to protect its citizens’ health and safety and improve the functioning of the single market. But: is regulation effective? The ‘difference-in-differences’ is a powerful ‘Counterfactual Impact Evaluation’ method to establish this.