Refugees are either nomadic (trying to make their way to a safer location) or settled in either a Wasteland Stronghold or Wasteland Trading Posts. Most refugees simply want to be left alone to live their lives. On occasion, though, some will offer themselves as a slave to be sold in one of the many markets throughout the Wastelands. The idea is that they hope to be kept by someone who will keep them in food, water and shelter in return for labor (or something). Many of the refugees who turned to slave work do so to help another; selling themselves so that someone else will get the profit from their sale. That is not to say that all slaves are willing.
Refugees walk a thin line in the Wastelands. They could head towards the civilization of the Fringe Zones around LATMA and take their chances in the city or stay out in the wastes and take their chances there. The city provides more opportunity for food, shelter and water and some sense of security - but also plenty of dangers from Dark Gangs, cultists, supers, etc. The wastes provide similar opportunities - and the hope that you'll be left alone.