Oh, you should go to WMD's website. He's good (even if nearly all of it ain't folk).

More importantly, folk clubs should never exclude that music that its makers say is or will be the new folk music - nor vice versa. The vine does not grow without its roots.

The relationship of that to being able to scratch a living is more vexed.

THe thing that distinguishes "earning a living in folk" from "earning a living in music" is the folk aspect, which for present purposes is wider than folk (1954 def). But even the wider folk is narrower than all music, and the amount one can earn is partly controlled by the amount of money in the market, and partly by the number of suppliers to that market.