I think they would be an economic gain as they may have more disposable income, since they are not in a family situation.
I've listed things that are psychological and behavioral, but they are also social and economic.
What should singles be looking for when choosing a city? Be sure to live somewhere with parks or opportunities to hike.
In addition to job and cost-of-living considerations, choose a city that provides opportunities for you to explore your interests and values. This will afford you opportunities to make friends with similar interests, which promotes higher levels of well-being and life satisfaction.
If you’re an outdoorsy person, your chances of meeting other outdoorsy people are greater in cities well-recognized for their outdoor-orientation (e.g., Boulder; Portland, Oregon), which might attract similar, like-minded people.
Likewise, some cities are noted for having a relatively larger percentage of single people.