Determine the central feature of politics
Indeed this manipulation is a central feature of politics: "Problem definition is the active manipulation of images of conditions by competing political actors. Conditions come to be defined as problems through the strategic portrayal of causal stories" writes, Stone (1989). Reaching at a consensus is a complex process. It is sufficient here to say that a single actor alone, cannot decide which policy image or understanding to come to dominate; rather, dominating definitions and understandings are determined through a process of dialogue and debate carried out within and across policy coalitions and policy process networks.
Indicators are used by policy makers, but studies that generate these indicators do not always lead to the definition of a problem for public policy. Indicators, on the other hand, are not simply transparent recognition of the facts. There may be highly charged debates about the methodology underlying the collection of data and even interpretation of data also is a matter of debate and requires considerable efforts to be accepted as a basis of the policy proposal.