> It is a serious point.
We'll have to agree to disagree there. It satires a position I don't hold. You both seem to assume that I believe immigration to be a 100% clear and unambiguous benefit, which isn't the case.
I'll go further; anyone who presents immigration arguments as simple is selling something.
In reality I'm making counter-points to someone I feel is trying to punch more than the evidence seems to allow.
Now to the points you've raised...
> The same claim - that immigrants are a benefit to the economy - has been stated without refute for 20 years now in the US
This thread is about the UK, and I learned all I know about the US from watching the movie Nutty Professor 2: The Klumps... but sure... if you like let's talk about the US. Why do you think nobody, apparently ever, refutes the benefits of US immigration?
> The participant rate of employment in the US...
Yep. Clearly a first-order effect of high immigration (legal or otherwise) is going to be competition for some types of jobs. I haven't heard any argument with that. There will be second-order and third-order effects on employment though.
It's also important to try to quantify the approximate size of each effect and the timescale over which it occurs. You're welcome to translate that "participant rate of employment" reference for an international audience. They didn't cover that in Nutty Professor 2.
> Now the taxpayers get to subsidize both the unemployed American worker and the immigrant (via health care, schooling, lost taxes, etc.)
I'm surprised that illegal immigrants have much access to healthcare & education access in the US. I'd be curious to know exactly what the cost of that is.
The third type of subsidy you raise there 'lost taxes' could really just be a short-hand for 'all government services', so isn't additive with the others. What's in the "etc."?
Don't misunderstand, having one group subsidising another is certainly a social justice issue, but it doesn't seem like it's in the top 5 biggest social justice issues in America. The Klumps were very informative on that point.
> How this is a benefit for anyone other than capital owners is something I'd love to hear.
From your references to H1B visas and to subsidising immigrants not paying taxes I assume you're objecting to both legal and illegal immigrants. Legal immigrants are much much easier to defend:
60% of the top US companies were founded by 1st or 2nd gen immigrants (Google, Apple, eBay, Tesla), and 15% of US presidents are 2nd gen.
Immigrants are also twice as likely as naturals to start a business, creating both jobs and market efficiency. Both of those things generate tax revenue and prolong the US position as the #1 economy in the world.
Even if you don't believe in trickle-down economics you'd sound like a crackpot to argue against that.
With illegal immigrants there's much less data and the arguments I've heard are are much less convncing... but I still don't believe anyone who presents it as a simple argument.