A few million people will start work this year with a bit of a raise. The minimum wage in 18 states is ticking up, giving workers increases of between 5 cents and $1 per hour.

In half of those states, the minimums will be rising automatically, to keep up with inflation. The other half, including Hawaii, California, Arizona, Colorado, Michigan and Rhode Island, increased their minimum wages through ballot measures or legislation. Some 4.5 million workers will be directly affected, according to the Economic Policy Institute.

Amid a nationwide debate on raising the minimum wage, states and some cities have taken the lead, with eight states and the District of Columbia passing new minimum-wage laws in the last two years.

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But states have also worked against municipalities looking to raise wage floors even higher. Missouri passed a ballot measure in 2006 to increase the current minimum wage of $7.85 an hour with the cost of living. Last year, however, the state clamped down on efforts in St. Louis to raise the minimum to $11 an hour.

The federal minimum wage of $7.25 an hour has not changed since 2009.