Over the last 10 years, Burkina Faso has experienced a reform of its cotton sector, and is now the largest African cotton producer and exporter. The cotton ”boom” consisted of a rapid expansion of cotton areas through the growth of land shares allocated to cotton (and new producers), together with an overall increase in total cultivated land. In this paper, we present an empirical framework to determine the contribution of total farmland changes in the increase of land dedicated to cotton, where both processes are represented by ordered endogenous variables. We then analyze data that we collected in rural Burkina Faso in March 2006 within this framework. From measurable indicators of farmer behavior and variables that measure farmer statements for the reasons of this behavior, we are able to identify both direct and indirect effects of the cotton reform on the extensive growth of cotton seed production. They are namely mechanization and technical assistance, labor intensification, enhanced managerial abilities (learning by doing and better environment for farmers), production incentives arising from the new local organizations of producers, guarantees and confidence stemming from the sector and an easier access to agricultural inputs.