1) Companies can find comparably trained and educated workers in non-US countries at cheaper rates because the U.S. education system doesn’t discriminate against less performant students. The education systems in many other countries are competitive at various stages and serve as strict filters against laggards, and there’s less consideration for meeting basic human needs in some countries. But in others there are different options where many students naturally find themselves (like less paying or blue collar work), and if that were to happen in the U.S. then inequality advocates will have a lot to say, and they wouldn’t be wrong.
2) There are a lot of realpolitiks at play when you have a multicultural society as people will often have dual allegiances. A CEO or hiring manager from country X or Y will want to favor their country of origin, naturally. It becomes easier to justify some decisions when the bottom line is also helped by said decisions by hiring cheaper labor.
3) The most expensive thing on the U.S. budget books for employers, employees and the government is social security and Medicare. Some countries simply deny their citizens and workers social security and access to welfare programs, which helps keep the cost of employing them down.
4) Even if a global corporate tax rate is set, it will still make labor in countries that don’t ask for social program contributions much cheaper.
5) The rule of law situation in some of these countries is less than ideal, and so living there can be a hit or miss, which is why H1-Bs are a popular choice for both employers and non-U.S. employees.
6) But still it seems that regional security and stability in some regions has led to permissive environments for unrestricted work. This situation isn’t going to change for nuclear countries, unless they’re like Russia (screwed by economic sanctions and expansionist desires).
So in the short-term, unless there’s some agreement to be made between countries for balancing their labor market loads, then economic sanctions seem like a terrible last resort.
Addendum, I think the hard truth for large cap companies is that they never should have been allowed to get that big, and in many cases their growth was aided by direct investment by the U.S. government. There’s an interesting lesson here for policy makers about balancing power and investments. Maybe the U.S. should divert future government spending to only its research labs.