I was taught letting factories go bankrupt and creating space and workers for the healthy ones is better than spending subsides and I still use this strategy in my games.
Industrial score grows slower, but your economy becomes more reliable and besides I mostly simply cannot afford to spend half my budget on subsides.
If the economy in general was functioning properly, then yes, subsidies are a terrible idea. And note that I'm not saying a player should do it; I'm saying that I agree with the AI's strategy.
Here's what I mean.
Let's use a clipper factory from AI UK in my last game as Austria. The clipper factory is level 41, and it draws 3200 in subsidies every day (yikes!). It is full of craftsmen.
Now, this factory is clearly a drag on the economy. No one needs 200 clippers a day. So, what should you do about it?
A) Let it die.
This will unemploy 400,000 craftsmen immediately. There is nowhere else for them to work, because the other factories are at full capacity and the state already has 18,000 unemployed POPs. Deleting the factory via bankruptcy will open a new factory slot. At current techs, these craftsmen can be reemployed in 10 years
assuming no population growth and factories with a two year construction time. You can shorten the time by building factories with only a one year construction time, but you are at the mercy of the market and perhaps your capitalists in this regard. If no one-year factories are profitable, you are forced to expand/build two year factories.
Also, killing this factory immediately cuts the demand for the following goods: 6000 timber, 7500 fabric, 2400 steel
, per day (plus a tiny amount of cement and machine parts as maintenance goods). Killing this factory immediately will hurt those other areas of the economy. There is a fabric factory in another state that produces 5000 fabric a day. It is borderline in its profitability, so a drop in demand like this will kill it, unemploying another 350,000 craftsmen who have nowhere else to work...
You can see where this is going.
B) Keep the factory open with subsidies forever.
The good news is that these POPs will remain employed. The factory will remain open, and will continue to consume inputs.
The bad news is that your government is on the hook for 3200 pounds
per day, which is way more expensive than unemployment subsidies. Still, the subsidies you pay here will also indirectly support other aspects of the economy.
That being said, those subsidies are coming from somewhere. The economic burden will hit the RGOs harder than the factories being subsidized.
C) Keep it open, but build tons of factories and bleed off labor into new factories as time goes by.
This is what I do (and why I need to move away from LF at times to adjust the economy, because capitalists suck at this). The factory will get subsidies, but other factories are built and expanded. Every time new factories are completed, the subsidies are removed long enough for labor to bleed into new industries, then they go back on (at least, until they are no longer needed).
The catch is that the AI can't do C. It simply does not know how to do it. So, while I practice C, the AI is left with A or B. I'd rather it choose B.
That's the best way to run an internal economy, yes. However, if all players practiced the same thing, then the economy would be worse off overall. The AI's subsidies are, to an extent, subsidizing you, as it's creating demand for your outputs with factories which aren't actually making a profit (or, in some cases, making anything at all). As the AI will always subsidize, the best strategy for the human player is always to concentrate his resources on those factories which are making money selling to the AI's inflated demand, rather than wasting his own cash on subsidies.
I will note that when I talk about moving the economic burden onto the RGOs, it also feeds into this inflated demand. The following RGO goods are subject to inflated demand, and thus can support an flagging economy thanks to AI subsidies:
1) Cotton: It's usually a good earner, even when fabric demand has crashed. The AI subsidization of fabric factories makes cotton worth conquering. You can employ millions of cotton farmers in 1935 thanks to the AI. And those cotton farmers buy your stuff.
2) Sulfur: No matter how shaky the market for military goods, I can always count on the AI to subsidize fertilizer factories. This keeps a significant number of POPs employed.
3) Coal: I shouldn't even have to discuss this one, although it is both a POP good and a factory input. Factory demand keeps the demand for coal so high that conquering China is an economic boon
even when other RGOs are failing.
4) Timber: Let me just throw this out there for you to consider: As Russia, I can conquer 65% of the world's timber, and despite the hordes of lumber that go unsold every day thanks to overproduction, I can employ tons of POPs in these RGOs.
Half the difficulty of modding V2 is learning how to recognize an unhealthy economy from little clues - it's very hard to spot delinquency until it's too late, by which point figuring out where the initial problem lies is impossible. You might find a late-game problem is actually caused by a shortage or surplus of one particular, seemingly irrelevant good 30 years before the collapse occurs. In the past, I've seen late-game military goods shortages solved by increasing fruit output on 1850s techs. The lack of a life need for iron miners in China was causing increased internal migration, which choked the growth of the iron supply, which caused a shortage 40 years later when the rest of the world was relying on tech-boosted Chinese iron production to keep growing. A 10% increase on fruit output on an early Industry tech allowed the Western nations to feed their wine factories without starving China's fruit supply, leading to a better industrial economy in the end-game.
This is also why imperialism in Asia helps the world economy so much. Plugging in those Chinese states into your economy and applying better techs to them earlier is a net win. No wonder the Chinese POPs hate my rule less than the Qing; their wages and access to consumer goods is 200000% better.