Monitoring and Evaluation of policies is intrinsically challenging and requires a very high level of technical capacity. Appropriate statistical indicators have to be selected and calculated to satisfy the needs of final users, linking the date to statistical demand. Appropriate classifications and definitions are also essential, while different data-sources and highly disaggregated estimations are needed; for instance, for small areas estimations and rural areas. Furthermore, Evaluation of a policy is a specific purpose, different from monitoring a project or long run economic analysis. The paper try to address the argument from a National Account prospective, rely on the assumption that this is an appropriate macro-economic framework for statistics and to base scientific studies.