On that topic, there's an interesting analysis of the report's data at May 2016 Author Earnings Report: the definitive million-title study of US author earnings | The Passive Voice | A Lawyer…
and the beginnings of a discussion of same at US ebook sales breakdown by genre - MobileRead Forums
I found an interesting point in the original article that doesn't seem supported by the facts he cites:
"...the ebook prices of the publishers’ most-heavily-promoted frontlist launches were, for the most part, still priced between $12.99–$14.99."
"The average price of a Big Five ebook, according to the report, dropped from $10.31 in January 2016 to $8.67 in May 2016."
“Naturally, when we noticed that Big Five ebook prices were on average more than $1.00 lower in May 2016 than they had been in January, our first question was: ‘are Big Five debuts now getting more competitively priced?’”
Sure looks to me like the debuts aren't more competitively priced. It's the backlist. Which makes sense. Many people (not me, but many) are willing to pay extra to get the new releases now.