Abstract
Migration is one of the key aspects of the Sustainable Development Goals (SDGs). To understand global migration patterns, develop scenarios, design effective policies, focus on the population’s needs, and identify how these needs change over time, we need accurate, reliable and timely data. The gaps in international migration data have persisted since international organizations collect data. To improve the data gaps, there is a need to conceptualize the types of gaps and pinpoint the gaps within the international data systems. To that end, the ultimate objective of this paper is twofold, (i) to review and categorize the gaps in the literature and (ii) assess the statistical data sources, i.e., United Nations Department of Social and Economic Affairs (UN DESA), Organization for Economic Co-operation and Development (OECD), International Organization for Migration (IOM), Eurostat, and the United Nations High Commissioner for Refugees (UNHCR). Our results demonstrate that the gaps could be categorized under (1) definitions and measures, (2) drivers or reasons behind migration, (3) geographic coverage, (4) gaps in demographic characteristics and (5) the time lag in the availability of data. The reviewed sources suffer from the gaps, which are not mutually exclusive (they are interlinked): the quality and availability of both migration flows and stocks data vary across regions and countries, and migration statistics highly rely on immigrants’ arrival.