> it does mean they weren't spending all of their time trying to figure out where they were going to sleep or where their next meal was coming from.

This is also a crucial concept in understanding why the poor stay poor: they simply can't afford to spend time and resources on the long term if they need to worry about meeting basic needs on a daily basis.

If you're interested in learning more about this, I would recommend to read Scarcity, a wonderful book that explores this in more detail: http://www.amazon.com/Scarcity-Science-Having-Defines-Lives/...

Book recommendation: Scarcity by Mullainathan and Shafir which discusses "scarcity traps" at length, esp. in the case of poverty, but also in other contexts (such as time scarcity for busy people, food scarcity for dieters, socialization scarcity for lonely people, etc.):

http://www.amazon.com/Scarcity-Science-Having-Defines-Lives/...