Do you think this migration trend will have a long-term impact on housing affordability in cities?

Short answer: without a doubt. Both illegal migration and legal immigration adds new demand pressures to the housing market which if not matched with a proportional increase in housing supply leads to price hikes and less affordable housing. This is just basic economics.

As I’ve noted numerous times throughout this space we currently have a 7 million unit affordable housing shortage. An influx of millions of migrants and legal immigrants only makes this worse not better. How much worse is debatable. As I noted three years ago in The Case for an Immigration Moratorium immigration increases metropolitan statistical area rents and house prices in an almost one to one ratio in both urban cores and surrounding suburbs with an even larger spillover effect on prices in adjacent MSAs. A study conducted a decade earlier found an approximately 1:1 ration between immigration inflows equal to 1% of a metro area population and house values and rents. A similar Australian study also found an almost 1:1 ratio between the gain in a postcode’s population due to immigration and housing prices with an estimated $6,500 increase in median house prices per year due to immigration. While the vast majority of scientific literature investigating this question finds a positive (directionally not morally) relationship between metropolitan immigration inflows and rents and housing prices it does not itself constitute an disparate impact on the real wages of renters by itself. It is only when you combine it with historically low new construction rates that peaked in 2005 and have come nowhere close since, historically high new construction inflation between 30–40%, and median rent hikes outpacing median renter household income that immigration becomes the water on a grease fire. Like water immigration is not in itself bad. Water is in fact essential to life itself, but it can become an accelerate of certain destructive forces when it’s mindless seen as an unconditional good.

Side Note: Just to give you an idea of how much new house construction rates have dropped since the early 2000s construction boom, new housing starts peaked at 2.27 million in January 2006 which according to NYT was a 33 year high not seen since the 1970s. Last month they were little more than 1.5 million. This disparity is much worse when you consider that we had 41 million fewer people 18 years ago.