A wave of protest with anti-regime slogans swept away Iranian cities in December 2017-January 2018. Scholars and observers offered different explanations for the emergence of this wave of protest. First hypothesis highlights the level of integration of a city in the political system related to their previous voting behavior. Second group of explanations stress economic hardship resulted from high inflation or unemployment rate. Third hypothesis echoes the youth bulge argument and contend that the new wave of protest should be explained with the introduction of a new cohort of youth into Iranian politics. Fourth explanation sees this wave of protest as a result of state’s policy to expand education throughout the country outside Tehran. Fifth explanation refers to the high level of draught in Iran and grievances generated by environmental problems. Sixth explanation considers this wave of protest as a natural sequence of daily protest in Iran by various social groups such as workers, teachers, retirees, and students. In late December 2017 a wave of anti-regime protest swept through Iranian dozens of Iranian counties. The geographic spread of protests was unprecedented in Modern Iranian history. We use the sub-national variation to develop and test main explanations about emergence of protest waves in developing countries. We consider six groups of explanations emphasizing economic adversity, climate change, higher education, political context, youth bulge, and diffusion through spatial proximity and internet. Based on original data on this cycle of protest and other new political and socioeconomic data, we present a discrete event history analysis of protests at the level of county for a 10 days period. Our results show robust support for the effect of higher education, internet, and spatial proximity to other sites of protest. The analysis also confirms that counties with higher portion of reformist vote were less likely to protest. This finding highlights the importance of the perceptions of political opportunities, and a contextual understand of the political configuration of protest. We find only partial support for the effects of economic deprivation, and no support for youth bulge and climate change.?