Measurements are used in policy-making to set targets, and to monitor progress towards targets. Think of CO2 emission targets, energy efficiency targets, waste recycling monitoring. When dealing with complex issues, the choice of metrics is not trivial! The issue of non-equivalence reveals that measurements may be precise, but they do not lead to univocal knowledge. As a consequence, policy objects are constituted also through the choice of metrics.
Why write a blog about complexity and science for policy? Because complexity matters for science advice to policy. Complex systems may lead to a situation in which science cannot provide all answers. Complexity refers to situations in which “the whole is different from the sum of its parts”, because of emerging properties at different scales of analysis. This situation is challenging for governance, because providing evidence on “the parts” will lead to different decisions than providing evidence on “the whole”.