Preface The series Handbook of Social Choice and Welfare presents in two volumes essays on past and ongoing work in social choice theory and welfare economics. The first volume which consists of twelve chapters in four partsPart I ( Arrovian Impossibility Theorems ) Part II ( Voting Schemes and Mechanisms ) Part III ( Structure of Social Choice Rules ) and Part IV ( Welfare Justice and Poverty )was published in 2002. This is the long overdue second volume of the handbook which also consists of four parts. In Part V ( Foundations ) some very basic issues in welfare economics and social choice theory are discussed. The topics covered include the initial insights behind and the basic functions of social choice theory the informational basis of normative and positive social choice theory the status of competitive market mechanisms as social choice procedures and the main ingredients of nonwelfaristic approaches in welfare economics and social choice theory along the line of the theory of functioning and capabilities.