摘要:Understanding change is critical to policy formulation. Who benefits, who loses from change, and what causes change are core policy questions. Panel data are central to understanding change, and this special issue of the journal is devoted to five papers examining change in wellbeing as measured by two waves of data from the Ethiopia Socioeconomic Survey (ESS). The papers cover changes in consumption poverty, multi-dimensional poverty, food security, malnutrition in the form of wasting and underweight status, and smoothing patterns of nonfarm enterprise activities. The ESS data is freely available for download and immediate use. While the papers in this issue draw from the first two waves of data (2011-12 and 2013-14), the third wave of the ESS (2015-16) is now also publicly available. The ESS is a collaborative effort of the Central Statistical Agency of Ethiopia and the World Bank’s Living Standards Measurement Study – Integrated Surveys of Agriculture program.