10/13/2026
This is one of the most important and least talked about ideas in housing economics, and we think everyone should understand it.
It is called filtering. Here is how it works.
When a family moves into a new affordable home, the home they left behind becomes available to the next family. That family's move frees up another home. And so on, all the way up the housing market. Like musical chairs, every move creates an opening for someone else.
Research from the National Multifamily Housing Council found that between 2015 and 2024, markets with higher levels of housing supply consistently recorded lower rent growth across all housing types, including the most affordable ones. More supply helps everyone, not just the people moving into new units.
But here is the catch. When we do not build fast enough, the whole process runs in reverse. Higher income households start competing for lower priced homes, prices rise across the board, and the families who need stability the most get pushed out entirely.
The City of Boise's housing needs assessment found that Boise needs 2,000 new affordable units every single year until 2033 just to meet demand. We are not there yet.
That is exactly why LEAP Housing exists, and exactly why this work cannot wait.
Source: National Multifamily Housing Council Research Notes, December 2024.
