Special interest groups and policy decision

Special Interest Groups, either of voters or the prospective contesters, play an important role in policy process, especially under representative democracy. These interest groups affect not only the outcomes in elections, but also in legislatures through contributions, lobbying and other activities. Most formal models of interest group activities focus on the campaign contribution aspect of the political activity. If there are two candidates, both promise for the same level of services, then the aggregate contribution to a candidate will have a positive relationship with the probability of winning in the elections. If we assume the services provided to the contestants are independent of the policy stance and electoral outcome the solution becomes difficult.