I found this very painful to read, it's painfully slow to get to the point...actually, it doesn't even answer the question posed in the title.

> Just as we need to adjust for price inflation, accounting for non-market sources of income is an essential part of making meaningful welfare comparisons over time.

The article never says how they account for non-market sources of income, i.e. those things without a price. I'm sure there's a dozen links to various papers, but I expect the question posed in the article to be answered in the article, rather than be fobbed off with pat tautologies such as "historians know about history"!