One of the most powerful ways for people to influence others to do something about certain causes is just to measure it. The most successful example being the creation of GDP as a concept to measure the economy. Suddenly, it displaced the more traditional metrics of population or military might (which involved more quantities than just number of troops involved).
There are always issues with measurements created. They do not perfectly measure the underlying thing we’re trying to quantify for two reasons:
- The measurement is inaccurate due to poor instruments used (proxies, poor surveyors etc)
- The measurement does not reflect the actual underlying concept we are trying to quantify.
The first point can be improved over time. The measurement accuracy would not be perfect but over time, as long as the measurement required is well-defined, we would be able to capture the quantity or at least get really close to it.
The second point is trickier and it is going to always be imperfect. And herein lies the danger of trying to make things measureable. The Goodhart law features an important observation we ought to be constantly reminded of as we’re bombarded with figures like GDP growth, inflation etc. It doesn’t mean they are false! But the key is to be able to distinguish the measure from the underlying concept of what the measure is supposed to imply.