Why is it so difficult to implement policies?

Governance and the Law

If you want to know an updated approach to policy reforms, then you have to read the World Development Report 2017
The main messages:

• Successful reforms are not just about “best practice.” To be effective, policies must guarantee credible commitment, support coordination, and promote cooperation.
• Power asymmetries can undermine policy effectiveness. The unequal distribution of power in the policy arena can lead to exclusion, capture, and clientelism.
• Change is possible. Elites, citizens, and international actors can promote change by shifting incentives, reshaping preferences and beliefs, and enhancing the contestability of the decision making process.
• Three guiding principles for rethinking governance for development are:
• Think not only about the form of institutions, but also about their functions.
• Think not only about capacity building, but also about power asymmetries.
• Think not only about the rule of law, but also about the role of law

You'll understand that the key element of any reform goes beyond evidence on what works and consensus. It should be clearly designed following specific steps. I suggest you have a look at it.

El gran Guillem Roma amb Alessio Arena