It's all about timing. Photo: Jörg Weingrill.

Distinguishing between ex ante and ex post assessments is an extremely important distinction that needs to be discussed and understood. If countries introduce socio-economic assessments as part of the technology approval process before deliberate release (ex ante), this decision will have a different implications than the two alternatives: requiring only assessment for post deliberate releases (ex post), or requiring assessments for both ex post and ex ante.

In the case of ex ante assessments, there will be implementation limitations in terms of the type of methods and approaches that can be used for the assessments. These are mostly driven by the lack of the specific technology adoption and/or use data. Most of the data available will come from confined field or performance trials, expert opinion, or other secondary data. An element of best methodological practice will the addressing the lack of knowledge and uncertainty with regard to many parameters in the assessment. In fact, most of the methods in ex ante assessments  are a type of projection, simulation, or may use foresight approaches for implementation.

In the case of ex post assessments, there is quite a bit of experience in terms of implementation, although much more needs to be done in terms of methods (See Smale et al. 2010).