An Obamacare Unknown

Dana Goldman, Michael Chernew, and Anupam Jena are unsure whether the healthcare exchanges will drive down healthcare costs:

Ultimately, economic theory predicts that the effect of insurance exchanges on insurance premiums will depend on two offsetting factors. On one hand, smaller, less-consolidated insurance companies may have less bargaining power with large hospitals, physician groups and pharmaceutical companies, which traditionally command substantial market power. Reimbursements to these parties, as well as costs to insurers, may rise in a fractionated market, and if so, these costs would be passed on to consumers as higher premiums. On the other hand, exchanges may inject competition into the marketplace, reducing premiums as even the smallest insurer can market its plans, forcing larger insurers to lower their premiums to remain competitive. Which theoretical effect will dominate in reality is an open empirical question with important policy implications.