Need more evidence that tax rates make a difference in an economy? The latest Bloomberg Businessweek features some interesting recent developments in Puerto Rico.

It’s 2 a.m. at the La Factoria bar in Puerto Rico’s Old San Juan, a hipster joint with a sagging couch, tile floors, and Christmas lights that wouldn’t be out of place in Brooklyn’s Williamsburg. While Get Lucky plays, tipsy couples slink out the doors onto the colonial city’s cobblestone streets and into this warm April night. At the bar, a 28-year-old hedge fund trader—the type of person who posts his SAT results on his LinkedIn page—is ranting about the tax code. He’s obsessed with it, complaining that the U.S. is the only major country taxing citizens on their worldwide income, no matter where they reside. That’s why he moved here.

Struggling to emerge from an almost decadelong economic slump, the Puerto Rican government signed a law in early 2012 that creates a tax haven for U.S. citizens. If they live on the island for at least 183 days a year, they pay minimal or no taxes, and unlike with a move to Singapore or Bermuda, Americans don’t have to turn in their passports. (Puerto Ricans are U.S. citizens but cannot vote in federal elections.) About 200 traders, private equity moguls, and entrepreneurs have already moved or committed to moving, according to Puerto Rico’s Department of Economic Development and Commerce, and billionaire John Paulson is spearheading a drive to entice others to join them. …

… “I’m worried about the shifting mentality among the electorate, people blaming problems on the rich, on business, and on capitalism,” says Peter Schiff, a onetime candidate for the U.S. Senate from Connecticut and a former economic adviser to libertarian presidential hopeful Ron Paul. “I’m afraid that the tax rates that are already high will get higher in the years ahead,” maybe up to 60 percent or 70 percent, he added.

Schiff, who runs Westport (Conn.)-based brokerage Euro Pacific Capital, relocated his $900 million asset management arm from Newport Beach, Calif., to San Juan in 2013. He plans to move to the island within the next several years.

States that lose these high earners lose their entrepreneurial talents, the talents that lead to new business opportunities, more economic growth, and more jobs.