The Arab Spring, which raised hopes for a wave of democratic reforms throughout the Middle East, has so far led to regime change in only four countries—Tunisia, Egypt, Libya, and Yemen. Why that dramatic series of almost synchronized uprisings reaped such modest dividends is the subject of a new paper, “Tracking the ‘Arab Spring’: Why the Modest Harvest?,” published in the Journal of Democracy, co-authored by Harvard Kennedy School Associate Professor Tarek Masoud.

“The Arab Spring that resides in the popular imagination is one in which a wave of mass mobilization swept the broader Middle East, toppled dictators, and cleared the way for democracy. The reality is that few Arab countries have experienced anything of the sort,” the authors write. “The Arab Spring’s modest harvest — a record far less inspiring than those of the East European revolutions of 1989 or sub-Saharan Africa’s political transitions in the early 1990s — cries out for explanation.”

Masoud and co-authors Jason Brownlee of the University of Texas, Austin and Andrew Reynolds of the University of North Carolina, Chapel Hill, examined the political, social and economic conditions under which the various national protest movements were launched and sustained. Their analysis identified two primary factors – a nation’s oil exports and the nature of its ruling structure – that directly influenced the outcomes in each country.

According to the authors, oil wealth endows leaders with extra repressive capacity, and the means to buy off regime elements that might otherwise defect in the face of protest.