Research that goes beyond self-reports echoes the sentiment that homelessness is overwhelmingly an economic issue. That's not to understate the impact that health, substance abuse and domestic violence play, either.
This is important to recognize, because families are falling victim to homelessness due to loss of jobs, insufficient income and the rising cost of living.
You could probably shake a few alcoholics out of that population, just like you could with the general population, but the overwhelming majority of them became homeless because of economic reasons. Those reasons, from here[1], include lack of affordable housing, unemployment, poverty, and low wages, in that order.
I have an uncle that became homeless after his divorce. It's a hole anyone can fall into if just the right bad things happen.
There's plenty of research available. I implore anyone who is reading this to Google "causes of homelessness", or start here[2] and continue researching by checking out the citations.
[1] https://www.nlchp.org/documents/Homeless_Stats_Fact_Sheet
[2] https://en.wikipedia.org/wiki/Homelessness_in_the_United_Sta...