How to test a person... (os)

...if or if not he/she is an economist. This small passage I found in book of Alan S. Blinder (Central Banking In Theory and Practice). And I liked it:

“...but please pardon me a momentary digression on comparative advantage nonetheless, for I have long believed that one true test of whether a person is an economist is how devoutly he or she lives by the principle of comparative advantage. And I don´t mean just preaching it, but actually practicing it. For example, I always harbor doubts about my economist friends who tell me that they mow their own lawns, rather than hiring a gardener, because they actually enjoy cutting grass. Such a claim is suspect on its face. But, more to the point, a true believer in comparative advantage should be constitutionally incapable of enjoying such activities; the David Ricardo inside him should make him feel to guilty.”