Policy analysis is "determining which of various policies will most achieve a given set of goals in light of the relations between the policies and the goals." However, policy analysis can be divided into two major fields. Analysis of existing policy which is analytical and descriptive—i.e., it attempts to explain policies and their development. Analysis for new policy which is prescriptive—i.e., it is involved with formulating policies and proposals (e.g., to improve social welfare). The area of interest and the purpose of analysis determines what type of analysis is conducted. A combination of two kinds of policy analyses together with program evaluation would be defined as policy studies.