Q. Relationship between individual preference and social choice?
Social Choice is a very kindred area. Some people don't make any distinction between the two while others make. Social Choice theory verily concerns with relationship between individual preferences and social choice. There is attempted some kind of aggregation of individual preferences though individual preferences refer to individuals' preferences from a social standpoint and hence many analysts including Arrow suggested the phrase individual values which means social values or value judgements or social views of individuals.
If we were to distinguish between the two, we would prefer to call a Social Choice that collective choice that involves all individuals to participate in decision making which affects them all, and a Public Choice that collective choice which includes those individuals who represent interests of all individuals, to participate in decision-making which affects all those who are represented by the participants. It means decision-making through legislatures, cabinets, parliaments, commissions, committees, tribunals, boards etc. would be all the cases of public choices whereas referendum and popular elections would be the cases of social choices. Some have preferred to call such exercises as problems of public choices and others have preferred to do vice versa. Still others have used the term Collective Choice for both types of exercises. Dennis Mueller suggested that Public Choice is a collective choice more on positive lines and social choice is collective choice more on normative lines. Actually, the term Public Choice came to be coined much later and works on Public Choice were using term Social Choice for the kind of decision-making processes today known as Public Choice. Public Choice Theory of Government Intervention is a growing area. It is said, in short description, to be an application of economics to study of politics. Actually, it is the use of economics methodology in analysis of political institutions, mechanisms, phenomena and processes, encompassing government, bureaucracy and judiciary. The methodology chiefly employed is one of the methodological individualism, which means it accepts contractarian, rather than organic, conception of State. The individual treated in this area of study is egoist, rational and utility-maximiser. Homo politicus is patterned on homo economicus. It chiefly deals with voting behaviour, voting systems and voting rules, possibility of logrolling and behaviour-modifying strategy, influence of pressure groups and party-politics, optimal majority questions in terms of associated costs, etc. Use of game theoretic framework, transaction cost framework and probability of whether an individual's vote is crucial in decision-making have engaged minds of many a worker in this sub discipline.
Wherefrom come rules and why there isn't one single rule for all kind of decision making from amending Constitution to building a rural road connecting a village with a highway? What are the activities, which may have to be collectivized? These are problems Public Choice deals with. Constitution-making by free citizens in terms of form, process and content as well as conditions and causes of revolution are very much questions some scholars have addressed to.