After years of relative equilibrium, the job market for nurses is heating up in many markets, driving up wages and sign-on bonuses for the nation’s fifth-largest occupation, The Wall Street Journal reports. The last nursing shortage more than a decade ago ended when a surge of nursing graduates filled many positions, and the financial crisis of 2008 led older nurses to delay retirement. But as the economy improves, nurses who held on to jobs through the uneven recovery are now retiring or cutting back hours, recruiters say.