Members of Congress sometimes bump into economic reality. Take Tuesday's vote on a bill to delay federally mandated minimum-wage increases in the Commonwealth of the Northern Mariana Islands and American Samoa, U.S. territories in the South Pacific. Congress agreed, 415-0, that a minimum-wage requirement can worsen economic mobility, though apparently only on small islands.

The government has historically granted the territories an exemption from minimum-wage requirements under the Fair Labor Standards Act. The last federal increase in 2007, to $7.25 from $5.15, required CNMI and American Samoa for the first time to raise their minimum wage by $0.50 per year until it reached parity with the states. The bill included American Somoa only after Nancy Pelosi came under attack for granting an exemption to a place that had factories for companies headquartered in her district.

Even with the minimum wage currently only at $5.55 in CNMI after three increases, the requirement has caused so much economic tumult that Congress has now passed two pieces of legislation, in 2010 and on Tuesday, to extend the transition period for the islands.

That's because the minimum-wage hikes have slammed local economies, which were already reporting years of declining GDP when the increases began. Government Accountability Office studies have shown that wage floors tend to do precisely the opposite of what their supporters purport. Employment in CNMI fell by 35% between 2006 and 2009, while average inflation-adjusted earnings remained largely unchanged. In American Samoa, employment dropped 19% from 2008 to 2009 after just one increase. The GAO said employers took "cost-cutting actions," including "laying off workers and freezing hiring."

Congress upheld the GAO's findings—at least for now. Conspicuously absent from Tuesday's debate were the usual defenders of minimum-wage laws. Rep. George Miller (D., Calif.), who sponsored the 2007 federal increase, voted yes to giving the islands a break. So did Rep. Hank Johnson (D., Ga.), who voiced his concern for island territories in a 2010 remark that Guam might capsize. The bill flew through Harry Reid's Senate by unanimous consent, an odd contrast with the vicious Congressional fight over raising the minimum wage in 2007.