For example “If we choose a left-wing Education Minister, what will test scores be in five years?” vs. “If we choose a right-wing Education Minister, what will

For example “If we choose a left-wing Education Minister, what will test scores be in five years?” vs. “If we choose a right-wing Education Minister, what will test scores be in five years?” and then we have a good guess as to whether the left-wingers or right-wingers have better education policy on this axis. If the measure of good education policy is higher test scores, in a world where the tests are updated at regular intervals (and they have to be, because in a changing world the things you need to learn will change), just win by changing the tests. That's the problem with people who try to reduce everything to maximizing a utility function. Each side can drop or add things to the tests based on what they consider to be important.