Nassul Kabunga is based at the International Food Policy Research Institute (IFPRI), Uganda Country Office. E-mail: email@example.com for correspondence. Matin Qaim is at the Department of Agricultural Economics and Rural Development, Georg-August University of Goettingen, 37073 Goettingen, Germany. Thomas Dubois is with the International Institute of Tropical Agriculture (IITA), Kampala, Uganda. The financial support of the German Ministry for Economic Cooperation and Development (BMZ) is gratefully acknowledged. We also thank two anonymous reviewers and the editors of this journal for valuable comments.
Yield Effects of Tissue Culture Bananas in Kenya: Accounting for Selection Bias and the Role of Complementary Inputs
Version of Record online: 1 MAR 2012
© 2012 The Agricultural Economics Society
Journal of Agricultural Economics
Volume 63, Issue 2, pages 444–464, June 2012
How to Cite
Kabunga, N. S., Dubois, T. and Qaim, M. (2012), Yield Effects of Tissue Culture Bananas in Kenya: Accounting for Selection Bias and the Role of Complementary Inputs. Journal of Agricultural Economics, 63: 444–464. doi: 10.1111/j.1477-9552.2012.00337.x
- Issue online: 21 MAY 2012
- Version of Record online: 1 MAR 2012
- (Original submitted June 2011, revision received January 2012, accepted January 2012.)
- endogenous switching regression;
We analyse yield effects of tissue culture (TC) banana technology in the Kenyan small farm sector, using recent survey data and an endogenous switching regression approach. TC banana plantlets, which are free from pests and diseases, have been introduced in East Africa since the late 1990s. Although field experiments show significant yield advantages over traditional banana suckers, a rigorous assessment of impacts in farmers’ fields is still outstanding. A comparison of mean yield levels between TC adopters and non-adopters in our sample shows no significant difference. However, we find evidence of negative selection bias, indicating that farmers with lower than average yields are more likely to adopt TC. Controlling for this bias results in a positive and significant TC net yield gain of 7%. We also find that TC technology is more knowledge intensive and more responsive to irrigation than traditional bananas. Simulations show that improving access to irrigation could lift TC productivity gains to above 20%. The analytical approach developed and applied here and the finding of negative selection bias may also be relevant for the evaluation of other agricultural technologies.