If there’s been a defining trend in American cities thus far in the 21st century, it’s been the rise of housing prices to astronomical levels. That’s also meant a huge increase in the number of people who aren’t able to afford a place to live, according to Gregg Colburn, a professor at the University of Washington who co-authored the book “Homelessness Is a Housing Problem: How Structural Factors Explain U.S. Patterns.” We spoke with him as part of our new “Finding Your Place” series exploring the reality of homelessness in America. And finally, the debt ceiling deal struck over the weekend faces a legislative test in Congress.