Preface to the handbook This chapter presents the book Handbook of Social Choice and Welfare in two volumes essays on past and on going work in social choice theory and welfare economics. The first volume consists of four parts. In Part 1 (Arrovian Impossibility Theorems) various aspects of Arrovian general impossibility theorems illustrated by the simple majority cycle first identified by Condorcet are expounded and evaluated. In Part 2 (Voting Schemes and Mechanisms) the operation and performance of voting schemes and cost sharing mechanisms are examined axiomatically and some aspects of the modem theory of incentives and mechanism design are expounded and surveyed. In Part 3 (Structure of Social Choice Rules) the positional rules of collective decision making (the origin of which can be traced back to a seminal proposal by Borda) the game theoretic aspects of voting in committees and the implications of representative democracy in the theoretical arena of social choice theory are examined. In Part 4 (Welfare Justice and Poverty) the possibility and implications of making use of interpersonal comparisons of welfare (with or without cardinal measurability) are expounded and the status of utilitarianism as a theory of justice is critically examined.