Negative externalities of pesticide use in the vegetable sub-sector in Kenya [Elektronische Ressource] / Ibrahim Ndegwa Macharia

NEGATIVE EXTERNALITIES OF PESTICIDE USE IN THE VEGETABLE SUB-SECTOR IN KENYA Von der Naturwissenschaftlichen Fakultät der Gottfried Wilhelm Leibniz Universität Hannover zur Erlangung des Grades Doktor der Gartenbauwissenschaften - Dr. rer. hort.- genehmigte Dissertation von M.Sc. Macharia Ibrahim Ndegwa Geboren am 18. Oktober 1974 in Nyeri, Kenia 2010 ii Referent: Prof. Dr. Hermann Waibel Institut für Entwicklungs- und Agrarökonomik Wirtschaftswissenschaftliche Fakultät der Gottfried Wilhelm Leibniz Universität Hannover Korreferentin: Prof. Dr. Ulrike Grote Institut für Umweltökonomik und Welthandel WiFakultät der Gottfried Wilhelm Leibniz Universität Hannover Tag der Promotion: 09.06.2010 iii Dedication To my beloved wife, Jacinta and my children Grace and Justin iv Acknowledgments Research for this study was made possible by the generous financial support by the German Academic Exchange Service (DAAD), as a PhD scholarship and the African Insect Science for Food and Health (ICIPE)-Impact Assessment project for data collection which is highly acknowledged. I am very grateful to Professor Hermann Waibel, for giving me the opportunity to conduct this study under his supervision. His support, advice, and guidance during the entire dissertation process are highly appreciated. My deepest gratitude also goes to Dr.