Here's one that'll confuse the Daily Mail - gays are good for house prices.
Shihe Fu estimates that a rise of one percentage point in the proportion of same-sex couples living in an area raises median house prices by 9 per cent even 10 years later, controlling for some obvious other things.
This suggests that gays improve neighbourhoods; they don't just choose to live in nicer places.
This could be because gays higher disposable incomes (they don't have kids) attracts better shops and restaurants. Or it could be that gays' better aesthetic appreciation enables them to spot attractive but under-priced areas, and to care more about urban regeneration.