> These sound good in theory
I disagree.
> but in effect they're an industry-specific labor subsidy.
What do you mean, "but in effect" -- that's clearly why they are being advocated.
> When the government "invests" in STEM education, what happens is that the companies that need to hire engineers save money both as a result of reduced training costs and as a by-product of increased supply driving down wages.
This is win-win (for domestic labor and capital [which is less tied to the domestic market], respectively) when you are training your citizens to take in-demand jobs. Its lose-win (on the same terms) when you are subsidizing and incentivizing foreign students to consume domestic educational resources to take in-demand jobs.