To make the economics clearer: the Netherlands has a national rent ceiling of €737 for social (rent-controlled) housing (and very long waiting lists in all the cities). In Amsterdam, the market rent for a 3 bedroom is probably around €1500 to €2000 (tough social housing are usually worth a bit less due to somewhat lower quality). Your dad is subsidized in-kind by probably around €800/months, but he's forced to consume it in the form of a very specific dwelling which he apparently doesn't value all that much. If he had the choice, he'd probably rather take the €800 (or even less) in cash and move somewhere else. But that option is politically infeasible due to the bad optics, even though economically it would be a Pareto improvement.
"If he had the choice, he'd probably rather take the €800 (or even less) in cash and move somewhere else."
This is how Section 8 vouchers work in the US. But unlike most welfare programs, the vouchers are limited and only a small portion of people who are eligible can get one.
