"If you have more than one reason to do something (choose a doctor or veterinarian, hire a gardener or an employee, marry a person, go on a trip), just don't do it. It does not mean that one reason is better than two, just that by invoking more than one reason you are trying to convince yourself to do something. Obvious decisions (robust to error) require no more than a single reason."
Not only do people use multiple reasons for doing something to convince themselves, but also to convince others. Recently Bloomberg borrowed my work (without citing) to discuss the Crypto-E-dollar. My piece was a warning, but Bloomberg portrayed the E Dollar as a viable solution strictly for economic reasons. Today they ran a new story on banning high denomination cash to aid law enforcement. They cited a paper done by a Harvard economist, Peter Sands, entitled Making it Harder for the Bad Guys: The Case for Eliminating High Denomination Notes. Here is an abstract of the paper.
"Now, the gold bugs will no doubt reply that under a gold standard big bubbles couldn't happen, and therefore, there wouldn't be major financial crisis. And it's true under the gold standard America had no major financial panics other than in 1873, 1884, 1890, 1893, 1907, 1930, 1931 and 1933. Oh wait. The Truth is that returning to gold is an almost comically (and cosmically) bad idea." Paul Krugman
This quote is the typical opinion of economists with a Keynesian bent. The only problem is it has no bearing in real economic history.