Thanks to ToddS for pointing me to the article Nine Reasons that Progressive Policies Deliver Prosperity and Freedom and to the Angry Bear blog on which it is posted.
…based on the long-term historical record, by pretty much any economic measure it’s progressive policies that deliver superior growth, prosperity, fiscal responsibility, opportunity, individual liberty, and a vibrant, robust economy and society.
This article is the big picture statement of what I think is true of progressive policies that I favor. That is why I favor them. They seem to work.