"Nine of the 13 states increased their minimum wages automatically in line with inflation: Arizona, Colorado, Florida, Missouri, Montana, Ohio, Oregon, Vermont and Washington. Four more states — Connecticut, New Jersey, New York and Rhode Island — approved legislation mandating the increases."

Economists who support a higher minimum wage said the figures are encouraging, although they acknowledge they don't establish a cause and effect. Hiring may accelerate in a particular state for many possible reasons.

"It raises serious questions about the claims that a raise in the minimum wage is a jobs disaster," said John Schmitt, a senior economist at the liberal Center for Economic and Policy Research. "The job data isn't definitive, but is probably a reasonable first cut at what's going on."

Economists have competing schools of thought on the impact of raising the minimum wage.

"Some studies, notably those lead by University of Massachusetts-Amherst economist Arin Dube, argue that there are no adverse employment effects from small increases in the minimum wage," according to The Washington Post. "Other studies, notably those led by University of California-Irvine economist David Neumark, argue there is an adverse effect."