A total of 94% of authors in the U.K. are white, with 2% Asian, 2% mixed race, and 1% black. (4% identify as "other.") The most recent census, in 2011, put the white population of the U.K. at 86%.

The findings come from the report on authors’ earnings—commissioned by ALCS (Authors' Licensing and Collecting Society) and written by researchers from the U.K. Copyright and Creative Economy Centre at the University of Glasgow—which was initially published in headline form last summer. The full report, which is based on responses from 2,696 ALCS members, has now been released.

The ALCS believes that the low rate of diversity is a by-product of the low author earnings exposed by the survey. As reported last June, the median earnings for "primary occupation authors" (i.e., writers who spend more than half their working time writing) are £10,497 a year. Accounting for inflation, this represents a 42% drop since 2006, when ALCS carried out its first survey of author incomes.

"There is considerable inequality of earning power among authors, with the highest-earning 10% of writers taking home about 70% of total earnings in the profession," the study found. "Meanwhile, most writers need a second job to survive, with just 28% of respondents making a living from writing alone without a second job, down from 40% in 2006."

This creates a situation in which many writers are supported by a higher-earning partner: "The survey tracks household income and finds that median household income for writers is £50,000 per annum and average earnings are over £81,000 per annum. These figures are conspicuously higher than those earned from writing alone, and highlight the extent to which additional work is required in households to subsidize authors’ incomes. This may well be a factor in the lack of diversity among professional writers, as people from less privileged backgrounds who want to write are less likely to have additional sources of household income."

The report continued: "The survey found that 94% of writers are white and a majority live in the south east of the country. There is also a significant gender pay gap—female primary occupation writers earned 74.9% of the income received by male writers."

Nicola Solomon, chief executive of the Society of Authors, said: "We are particularly concerned about the implications of these findings for diversity across the industry. It is clear that authors are having to subsidize their earnings from writing with other forms of income—this inevitably favors writers from more privileged households and backgrounds. There is a danger of writing becoming an elitist profession which excludes new and diverse voices."

She added: "This report should act as a wake-up call for the industry. We look forward to working with authors and publishers to ensure that reward is fairly shared and the ecosystem as a whole is able to thrive."

A version of this story appeared in BookBrunch.