This Research in Progress report is divided into two parts. Part I studies the operationalization and indicators of the different elements of complex humanitarian emergencies. It includes discussions of what to try to measure when looking into the magnitude of emergencies and why, what data are available for that purpose, and what are the basic limitations concerning recency, accuracy, comparability and availability of such data.The paper is a contribution to future studies concerning quantitative indicators of crises. It outlines only methodological issues, leaving out a discussion of policy implications at this early stage of the analysis. The paper also includes some preliminary conclusions of analyses of data for a large number of developing countries on the different elements of crises, such as hunger, diseases, deaths due to wars, and displacement.The elements of complex emergencies are seldom systematically measured, and are in fact often unmeasurable. This is likely to lead to major problems and even distorted conclusions in statistical analyses. Yet, such problems often do not attract sufficient attention.Part II contains a discussion of Amartya Sen's entitlement theory as a plausible explanation of humanitarian emergencies. It is suggested that it can be used for organizing the search for causes of emergencies by incorporating new types of entitlements that cover the various - not only economic, but also political, institutional, cultural, etc. - causes of emergencies. The preliminary remarks of Part II should also be useful in building a model of causes of humanitarian emergencies. Part I of the paper examines a few variables to illustrate the existence and extent of human suffering, and discussing causes of emergencies (Part II) with a somewhat modified entitlement approach broadens the analysis of complex emergencies.