Subsidiarity is the principle which holds that issues should be solved at the most local or immediate level that is consistent with their resolution. Oxford lexicon defines it as “the principle that a central authority should have a subsidiary function, performing only those tasks which cannot be performed at a more local level”.
Subsidiarity and decentralization improve the ability of the government to quickly respond to problems. Distance from a problem makes it more difficult to gather relevant data. Higher level of government responding to low-level problems means that said level of government will have to be larger and more complex in order to handle increasing number of issues. But this size and complexity also result in it being less efficient and slower to respond, as the detection of, assessment of, and response to the problem have to move through greater number of levels and steps to reach the relevant portion of the system.
Subsidiarity improves the ability to relate to and accurately assess the problems which need solving. High-level politicians and academics live in ivory towers, unable and unwilling to understand how things on the ground look. Democracy and democratic elections do not remove this problem. Rather, they amplify it, because politicians have to fool the people into electing them, and not that other group of pathological liars. As a result, they do not care about the real issues on the ground, but rather focus on the ideology and ideological posturing (“wokeness” being an obvious example). Thus an unelected local authority was often superior to elected central authority.
Government also has a natural tendency to become ever bigger and more centralized. This tendency has to be actively counteracted, and the only way to do so is by limiting not only the size but also the impact of the higher level elements of the government.
Subsidiarity helps prevent any one issue from affecting the entire system. Humans, especially politicians, are very bad at assessing the reality and making good decisions. It takes a lot of experimentation to reach a workable solution, which is why it is a bad idea to randomly replace things which have worked for decades or centuries with something “better”. Something may be a disastrous failure, yet still work for decades because sufficient elements of the old system have survived to mask the true scale of the failure.
Further, different areas of the world have different conditions. Climate, culture, history, tradition, biology, geography and other factors all have impact on whether a certain political system or solutions will work or not. It is impossible to implement the same system all across the world and have it work equally well.
Because of these issues, it is never a good idea to have a large area – much less the entire world – utilize the same solution. A system which may work well in one country may well destroy its neighbour. Instead, every area – country, province or even a city – should be free to determine and implement solutions which work best for it. But for this to work, there needs to be political decentralization, and there need to be borders.
Subsidiarity, not democracy, is a key to a free society and functional political system. In fact, democracy is dangerous precisely because it runs against the principle of subsidiarity. It increases authority of the central government because it creates an illusion that government is “of the people, by the people, for the people”. Large central government is much like a piece of faeces: it attracts the flies and stinks the whole place up.