A major component of the Rural Income Generating Activities (RIGA) study was to construct comparable income measures from selected multi-purpose household surveys (see table in Annex I). The aim of the exercise was to provide annualized benchmark aggregates spanning four continents which, despite pervasive differences in the quality and level of information available in each survey, would be suitable for cross-country analysis. The objective of this document is to describe the methodology used in constructing the household income aggregates and their components included in the RIGA database. Section II of this report discusses the general principles underlying the estimation of income aggregates. Section III describes the different components and breakdowns of our income measures and discusses some of the methodological issues behind their construction.2 The final\nsection of the document describes the data transformations and imputation procedures applied. More country-specific methodological issues and idiosyncratic adjustments are addressed in Annex IV.