Why (and how) total numbers should matter for animal experimentation policy.

In many countries, overall animal experimentation is not significantly decreasing or becoming less severe. Does this show that these countries' programs to promote alternatives and the "three Rs" of "replace, reduce, refine" are failing? Scholars and activists sometimes take this for granted, but representatives of "three Rs" programs have disagreed. This article makes two contributions to the debate: one conceptual and one normative. First, it draws attention to the distinction between evaluating impact (whether a program makes a difference) and evaluating sufficiency (whether a program makes enough of a difference to achieve its goals). Total numbers are typically unhelpful in assessing impact, but depending on goals, they can be relevant in assessing sufficiency. Second, this article argues that an overall decrease in harm to animals in experimentation is a sensible policy goal. This article concludes with suggestions for how to go beyond the "three Rs" to effect overall change.