The Politics of Development Metrics and Measurement: Impact Evaluations in Fairtrade-certified Plantation Agriculture Angus Lyall and Elizabeth Havice ABSTRACT This article presents an analysis of impact evaluations in the case of Fairtrade International in order to track the political effects of metrics and measurement procedures in development practice today. Metrics or ‘indicators’ have long been understood to have the effect of transforming the political visions of socioeconomic change that shape development interventions into seemingly non-contentious, technical models. The common practice among develop- ment organizations of using such metrics as evidence of apolitical, technical development outcomes has wide-ranging implications for the field of de- velopment and for development subjects. The article explores two specific implications by detailing impact evaluations on three Fairtrade-certified cut- flower plantations, which Fairtrade International contracted to inform a 2014 revision of its certification standards. The authors find, first, that debates over competing visions or definitions of development became concealed in techni- cal debates over adequate metrics and measurements; and, second, that such debates over metrics and measurement consolidated the roles of experts and expert knowledge as mediators of what development can or should be. These findings enhance prior critiques of the supposed neutrality of development metrics by illustrating empirically how the processes of defining metrics and measurement conceal and circumscribe political debates over the meaning and making of development practice. INTRODUCTION Metrics of social and economic change have long been of central concern in efforts to classify development (Drewnowski, 1977; Hicks and Streeten, The authors are grateful for feedback on an early draft from Peter Vandergeest, Lone Riisgaard and Stefano Ponte. We shared a later draft with three Fairtrade representatives whose work is highly relevant to the content of the article: Martin Sch¨ uller, Development Policies Man- ager; Wilburt Flinterman, Senior Advisor for Workers’ Rights and Trade Union Relations; and Jesse Hastings, M&E Learning Manager. We thank each of these individuals, along with the anonymous referees of this journal, for their input. We would also like to thank the plantation workers, consultants and Fairtrade officials who participated directly in the original studies on which this article is based. All errors and omissions are ours alone. Development and Change 00(0): 1–23. DOI: 10.1111/dech.12452 C  2018 International Institute of Social Studies.