With nine U.S. health insurance co-operatives announcing closure or being forced to shut down during the past year over concerns about their solvency, the viability of their business model has come into question. Created under the 2010 Affordable Care Act (ACA), the co-operatives were designed to provide competition in the health insurance market and protect consumers from aggressive pricing by some of the larger and more established for-profit insurers. However, with the recent hemorrhaging, only 14 of the 23 health insurance co-ops have survived. Meanwhile, the casualties are stacking up. For one, more than 500,000 customers of the failed co-ops must find alternative insurers. Secondly, health insurance premiums could rise next year with the reduced competition. Premiums could rise also because a projected flat growth in enrollees for next year might mean fewer healthy people in the risk pool for insurers.…