@Framesticker
MP = military police
@OP
HR is a very powerful civic, it seems you want some numbers or demonstration so I will give what I can. First of all it is true, that putting MP everywhere does in fact have questionable advantages (check my sig link). Summarising it, the extra gold cost of the population and military unit, means you get little profit, and if you go into pacifism, a loss. Keep in mind, this is in short term, if you are growing cottages and don't need to rush to a short term tech (ie. you want full power in 100 or so turns) depending on your difficulty it may be alright. Otherwise I'll skip to some good examples.
One case where it is always worth it is a bureau acad cap (even though oxford comes later, it is not necessary to "profit"). Assume MP and pop maintenance cost = 2. From one cottage, you get 1 commerce. Add in bureau bonus, 1.5 commerce. Add in acad + lib, 2.125. So thats an immediate profit (though meager) of 0.125, although it doesn't cover the initial cost of production, in 10 turns, this becomes 4.25, a profit of 2.25. This value improves with uni, oxford and cottage growth of course, so it becomes clear rather profitable.
TLDR: After 10 turns, profit of 2.25 with only acad, bureau and lib. As you build more beaker bonus buildings + cottages grow, becomes much higher.
Also consider financial trait, profit much more rapid.
2nd case where HR is useful.
Generating GPfarm. This is, somewhat of a special case one, as you may not always use a size 16+ GP farm. The idea is that you build at least NE in this city (hopefully pacifism + GL). Typically a Golden Age is also included, but for purposes of this, I'll only assume NE. At this stage you should have generated 1-2 GS, we assume 2. So next GP costs 300. The idea in this city is to generate as much GPs as possible in time to bulb either to astro or lib. A city like this you expect should have at least 6 specialists (or you picked wrong city). Lets assume something like 9 MP. So cost 18 gpt. 6 specialists = 18 bpt + lib = 22.5 bpt. Now, as you are bulbing the GP generated, you expect a minimum of 3 GP to be generated. 3 GP is 1200 GPP. You earn GPP at a rate of 36 per turn. So in 33 turns you get 3 GP. Each GP (scientist) can bulb for 1500 beakers. So 4500 beakers total. This is about 135 bpt, converted to consider each scientist this is something like 25.5 bpt for each scientist, well worth their cost. If you have pacfisim or GA, then more GPP generated, more GP and hence more "value". A best case scenario GP farm may well generate 5+ GPs within a space of 30 turns, depending on how you plan things.
TLDR: The costs of a large GPfarm are insignificant compared to the amount of beakers it can generate from bulbing, or indeed, from settling the resulting GPs
3rd case, military build up.
As you build up military, to keep production going, HR offsets whipping unhappiness (until army moves of course).
Of course, in the first 2 cases, you want the cheapest MP possible, to reduce production cost.
Thats all I can think of atm, hope this helps.