Abstract: | This article argues that, although effective strategic choices for achieving global development goals need to be based on assessments of the costs and benefits of alternative approaches, existing methods of arriving at such assessments are highly unreliable, in particular deriving from implausible and restrictive assumptions and often depending on data of poor quality, and on the pretence that the future can be adequately known. Such weaknesses can be mitigated, but not easily overcome, without abandoning deeply held technocratic presumptions. |