I wish that government policies could be based on the scientific method: gather information, present a hypothesis, test it in a well-defined manner, analyze the results, and see if the hypothesis is true or not. If not, discard the hypothesis and, if needed, formulate a new one. Progress is made by implementing policies based on confirmed hypotheses, and repealing policies based on failed ones.
I’m a student of science, and so believe that things should be tested by experiment. However, the consequences of a failed experiment in the lab are very different than those in the real world: in the lab, you might lose your eyebrows, your funding, or maybe your reputation. At the very worst, you might be killed or seriously injured by a spectacular failure, but this is extremely rare. Even if a theory is shown to be incorrect, useful data is generated, a better theory can be crafted, and a new experiment with the same starting conditions can be conducted.
The real world is much less forgiving: a policy mistake can cost trillions of dollars and many lives. The realities of bureaucracy and government can take a good idea, implement it poorly, and make things worse. Due to the inertia of society and bureaucracy, some flawed policies can be essentially impossible to undo.
Thus, it is extremely important to learn from the past, recognize which policies failed and which worked, make informed decisions, and make policy decisions based on fact and a realistic worldview.
Unfortunately, things rarely work this way, and the same mistakes are made over and over again. As a student of science, this annoys me to no end.