Sorry to keep beating an old drum, but a new survey report on author incomes was released late last week, and it is just as useless as the previous ones.
On Saturday The Authors Guild reported that author income fell 42% since 2009:
The Authors Guild’s 2018 Author Income Survey, the largest survey of writing-related earnings by American authors ever conducted finds incomes falling to historic lows to a median of $6,080 in 2017, down 42 percent from 2009.
The Authors Guild surveyed its membership and the members of 14 other writers organizations in 2018, receiving detailed responses from 5,067 authors. This included traditionally, hybrid and self-published authors who have commercially published one or more books. When discussing median incomes, the survey looked at both full-time and part-time authors.
The respondents reported a median author income of $6,080, continuing a sharp decline over the last decade: $8,000 in 2014 and $10,500 in 2009 (per the Authors Guild’s 2015 Survey), down again from $12,850 in 2007, as reported in a joint Authors Guild/PEN survey.
You can download the report on The Authors Guild's website. It does not contain all of the data or the survey questions, however. (For example, there's no info on the age distribution of the 2009 survey respondents - was the average age lower than in 2018?).
The Authors Guild report in particular is flawed because it is based on a self-selected survey group where self-published authors are under-represented and retirement age traditionally authors are over-represented.
As any polling expert can tell you, when you let individuals select themselves into a group, you create a biased sample that doesn't reflect the larger population. The formal name is self-selection bias. It is a known problem in research in sociology, economics, psychology, and many other social sciences, where it even has a pithy acronym (S.L.O.P., for "self-selected listener opinion poll").
When it comes to The Authors Guild survey, the survey group is biased towards older traditionally-published authors. Senior citizens are twice as prevalent in the survey group as in the population as a whole, while younger authors are almost nonexistent among respondents.
TAG tries to brush the issue off with the argument that "very few authors publish before the age of 35". While that may have been true in earlier eras where publishers acted as gatekeepers, it is now 2019, and self-publishing has has made it easy for anyone to publish. (And frankly, there's no current data to back up that claim about the typical age of first-time authors.)
Furthermore, self-published authors only accounted for a quarter of the survey group when common sense would tell you that, when it comes to the industry as a whole, indie authors outnumber traditionally published authors by a significant margin.
While it would be great to have useful data on author incomes, this report doesn't actually tell us anything we can use. Its poor methodology invalidated its results, making it a complete waste of everyone's time.