>and it certainly doesn't follow that nobody is harmed by any permissive migration scheme.

I've seen these responses a lot to the economic case for migration, the general tone being that economists are too simplistic in their model of migration, some fall through the cracks and so on, but what always seems to be ignored is that the exact same argument applies to political measures limiting migration.

In fact the politicization of migration restriction for populist, racist reasons and so on is significantly stronger and a bigger threat than the downsides of the economic case for open migration.

People in tech are very well acquainted with this logic when it comes to regulatory capture.