Do Premiums Increase after Health Insurance Mergers? – A Reassessment of Guardado Et Al.'s Findings

Guardado, Emmons, and Kane (2013) found that premiums in Nevada increased by 13.7 percent following the merger of United Healthcare and Sierra Health Services in 2008. Using methods similar to those used by Guardado et al., we study a series of more recent mergers to see if their results generalize, particularly given recent changes in the health insurance industry. We find that the results of their analysis do not generalize, with no pattern of higher premiums following recent mergers and, in fact, lower premiums following the mergers with the highest combined shares, a result consistent with lower medical costs or other efficiencies