I suggest looking at whether real estate prices in a particular locale have been rising or falling. If immigration is “ruining” a particular city, we would expect homes and other property values in that place to become much cheaper.

Home values have historically served as a strong indicator of the health of a city. Consider Detroit. It was one of the premier American cities in the mid-20th century, but the region lost a lot of its automobile industry to foreign competition, and crime rose precipitously. The city also was poorly managed. The result in real estate markets was a collapse in prices. If anyone asked you to point to quantifiable evidence for the decline in Detroit, it was easy to do so.

Detroit has undergone a renaissance since its nadir. New businesses have opened, crime rates have fallen, and the city feels more lively again. And since that turn of fortune, often dated around the 1990s, Detroit real estate has made a major comeback, putting aside the price collapse of the Great Recession in 2008. Home prices are not a perfect measure of how the city is doing, but they do pick up major and radical trends, both on the downside and on the upside.

The nice thing about market prices is that they show how buyers weigh the benefits of immigration against costs. Say some new immigrants have moved into your community and the quality of the schools has declined somewhat and traffic is modestly worse. At the same time, there are new businesses, the streets feel more lively, and it is easier to get a good local plumber. In the abstract, it is hard to tell which effects might be most important. But individuals, when bidding for homes or deciding to sell, make their own judgments. What happens to the home prices is a reflection of the collective judgments of people with major decisions about their lives on the line.

Of course in most of the Western world, including Malmo, real estate prices are healthy and very often rising.  Here is the full Free Press link, by yours truly.  The piece of course does cover the usual caveats, such as bubbles and busts, but note NIMBY factors will not alone reverse the basic conclusions.