This paper investigates the determinants of the decision to switch from cultivating bush to high yielding climbing beans and estimates the causal impact of adoption of climbing beans on productivity based a nationally representative sample of bean producing households. An endogenous switching regression model is used to account for the endogenous nature of adoption and accurately quantify the differences in productivity between climbing and bush bean technologies. Adoption of climbing bean varieties substantially increased over the past 15 years. Elevation, rainfall, and cropping systems are important determinants of adoption of climbing beans. Adoption of climbing beans increases productivity by 21 percent among adopters compared to 48 percent for non-adopters.