The Authors Guild (external link) reports some depressing conclusions about writers and wages. Although their report is about book writers, I think their study applies to non-fiction magazine article and newspaper article writing as well.
Their report states that only 39% of book authors support themselves exclusively through writing. Full time writers, the Guild concludes, make on average only $17, 500 a year. Part time authors make $4,500.
These are steep declines from when the last time the Guild made a survey, back in 2009. But they mirror the conclusions I’ve made about writing, the internet, and the collapse of the wage floor. (internal link)