Public policy has many definitions, but generally may be thought of as the programs of action that government deliberately pursues, and whatever government selects not to do. Government is involved in most every aspect of society to some degree. Public policy also involves government choosing not to take action in some areas. The area include situation where interest groups want government to intervene. Public administration need to understand the complexities of public policies because public administration makes policy and is also affected by public policies. Public policy is a very large subfield of political science and a standard area include in the study of public administration. Most public policy is reactive in nature. That is, policy is formulated as a response to an existing problem rather than being proactive, which involved trying to involved issues before they actually arise. It is also created in a process that includes formulation, implementation, and evaluation. It is also created in the political arena and typically does not use a rational decision-marking process for most issues.