Robert F. Kennedy once said that a country's gross domestic product (GDP) measures “everything except that which makes life worthwhile”. The metric was developed in the 1930s and 1940s amid the upheaval of the Great Depression and global war. Even before the United Nations began requiring countries to collect data to report national GDP, Simon Kuznets, the metric's chief architect, had warned against equating its growth with well-being. GDP measures mainly market transactions. It ignores social costs, environmental impacts and income inequality.