If after more than six years as President the economy hasn’t increased take-home pay, here’s an idea: Declare that millions of Americans get a raise by government fiat.

That’s the latest brainstorm of President Obama’s Labor Department, which on Tuesday released its new regulation governing which salaried workers are eligible for overtime pay. The new rule would more than double the threshold below which workers automatically qualify for time-and-a-half to $50,440 a year from $23,660. The new threshold will also be indexed...