Browsing the web, I came across the following claim by Lew Rockwell:
" Need I note, as this article indirectly indicates, that the whole world is reading Rothbard, but that Friedman is almost a nobody outside of mainstream academic economics?"
He provides no support for the claim—the link is to a collection of links on Rockwell's site to works by Rothbard—so I thought I would look for some data. I do not know where one would find figures on what books people read, but the most readily available source for books they buy is Amazon, which ranks books according to sales; rank 1 would be the best selling book on Amazon, rank 100,000 would be the hundred thousandth best book. So I searched Amazon.com for books authored by Murray Rothbard and books authored by Milton Friedman, in each case sorting by sales to find the ones that sold best.
Friedman, Money Mischief: Amazon Bestsellers Rank: #2,132 in Books
Friedman, Capitalism and Freedom: 40th Anniversary edition: Amazon Bestsellers Rank: #2,120 in Books
Friedman, Free to Choose: Amazon Bestsellers Rank: #3,719
Rothbard, A History of Money and Banking in the United States: The Colonial Era to World War II: Amazon Bestsellers Rank: #34,118 in Books
Rothbard, The Case Against the Fed: Amazon Bestsellers Rank: #22,316 in Books
Rothbard, The Mystery of Banking: Amazon Bestsellers Rank: #49,523
Rothbard, America's Great Depression: Amazon Bestsellers Rank: #63,960
Readers are welcome to check the numbers themselves—they will, of course, be a little different each time you check them, since Amazon updates rankings on the basis of current sales—or search for a Rothbard book with sales anywhere close to the top three I found for Friedman.
I do not usually waste my time defending my father, a job he did more than adequately for himself, but this seemed like a striking example of one prominent Austrian—Lew Rockwell founded the Mises Institute, which publishes several of the Rothbard books I listed—who appears to be living in a fantasy of his own invention.
He is, of course, more than welcome to post a comment here providing the data to support his claim.
A correspondent points me at data on relative online interest in Milton Friedman and Murray Rothbard.
In fact, according to Google AdWords, there are approximately 135,000 searches a month for your dad's name globally. That's in comparison to 8,100 for "murray rothbard" and 22,200 for just "rothbard". This is based on a 12-month average. Google Keywords
available at: https://adwords.google.com/select/KeywordToolExternal
Another metric to look at is Google Trends which puts this information into a graph over time, and allows keyword comparison. Take a look at:http://www.google.com/trends?q=milton+friedman%2C+Murray+Rothbard