The key question is not how long a homeless person has been on the street in a given area, nor is it where they grew up. The key questions are "Were you homeless when you came here?" and "How long did you live here before you became homeless?"

I chat with a lot of homeless people locally. Almost to a person they were homeless when they came here. Many of them have had temporary housing in the past, so when they answer the typical questions our social service agencies ask they appear to be locally-generated homeless people. 

However, the claim that 70% of our homeless are locally generated doesn't pass the smell test. Eugene has 5-10 times the concentration of homeless people as the nation as a whole. The only way we could have so many home-grown homeless would be if we are 5-10 times worse at creating jobs or much more likely to generate drug addicts and mental health issues than the nation as a whole. Such a claim is preposterous.