From the World Development Report 2013.
Quantitative analysis confirms that changes in labor earnings are the largest contributor to poverty reduction. In 10 of 18 countries, changes in labor income explain more than half the reduction in poverty, and in another 5 countries, more than a third. In Bangladesh, Peru, and Thailand, changes in education, work experience, and region of residence mattered, but the returns to these characteristics (including labor earnings) mattered most. Just having work was not enough, given that most people work in less developed economies. What made a difference for escaping poverty was increasing the earnings from work.