This study provides, for the first time, an overview of the growth record of the Middle East since 1820 and inserts it into a comparative framework. GDP per capita estimates are offered for individual countries in the region for the benchmark years of 1913, 1870, and 1820. The Middle East began to participate in modern economic growth during the nineteenth century. Yet, per capita income differences with the high-income regions of the world widened considerably until World War I. In the twentieth century, the most important single factor contributing to increases in per capita incomes was oil.
This is a subject about which we know little and where, in all likelihood, our knowledge will not grow greatly.Charles IssawiIssawi, Economic History of the Middle East, p. 103.