"According to the study, the average playwright earns $25,000 to $39,000 annually, with about 62 percent of playwrights making less than $40,000 and nearly a third pulling in less than $25,000.Hm. Don't those numbers seem optimistically high?"
Well, if I read the study correctly, that includes income that's not related to theatre. Furthermore, playwrights surveyed said that 50% of their income, on average, is not theatre-related. And what IS theatre-related includes things that are not specifically writing (21% said Teaching for example). They reported 15% of their income from royalties, for example. That means something like $6,000.00 on average.
I wasn't surveyed, but there are peers of mine who were so I feel like I can speak to this myself, un-anonymously. My non-theatre related job is being an Assistant Director at a non-profit and I earn, in that job alone, well over the average noted above annually. How much have I earned from writing over the last five years? Maybe $3000? If you include non-theatre gigs? If you included only playwriting... I dunno. Half of that? Less?
I'm far from a mid-career writer...I'm still fumbling my way out of obscurity. But if you included my non-theatre related income in this survey, I'm a top earner.