Money: economists make good money. The median salary for a new financial economist is $112,000, and that is if they work inside the academia. Salaries for non-academic economists are usually much higher.
Impact: to work at the most important economic institutions (FED, World Bank, IMF, other central banks, etc.), you need a PhD economics.
Signal of intelligence: having a PhD shows that you are very intelligent. In fact, getting a PhD makes you smarter.
Chance to be justifiably arrogant: every serious investor, whether he's an economist or not, must have read books like "A Random Walk Down Wall Street," "Security Analysis," or "The Intelligent Investor." The authors of these books don't seem to think highly of security analysts, investment bankers, or the like. In fact, the reason I liked "A Random Walk" was that Malkiel made fun of Wall Street people so often. Of course Wall Street people can hate economists if they want to, but they can't say that economists are stupid because they don't understand what economists do.