Paper short abstract:

Recent forms of evidence based practice react not only to the ubiquitous spread of cost-benefit-analysis, but also to changing popular and legal demands for higher and more transparent forms of accountability and liability.

Paper long abstract:

This paper argues that evidentiary practices seek to establish matters of fact through classifications and the identification of regularities in order to allow predictions, open spaces for controlled interventions and to permit attributing liability. Evidentiary practices are about crossing the gap between predictability and unpredictability. To govern, but also to challenge forms of governance by holding those in power accountable, this gap needs to be navigated. This means establishing as many things as possible as matters of fact and thereby rendering the unpredictable more predictable. A rest of unpredictability, though, appears inexorably tied to human endeavors. For experts of all sorts and those who take decisions that affect public life, the gap between predictability and unpredictability proves a difficult dilemma. They are expected to intervene and prevent unwanted developments (accidents, famines, epidemics, etc.), yet their interventions have unintended, sometimes undesirable consequences. To do this audacious work and still be held liable, some ambiguity in the justification of their intervention and what its precise impact was seems unavoidable. This paper asserts that recent forms of evidence based practice - establishing indicators, building rankings, designing interventions as experiments - react not only to the ubiquitous spread of cost-benefit-analysis, but also to changing popular and legal demands for higher and more transparent forms of accountability and liability.