In the last 18 months, at least 8 US hospitals have closed their doors after being bought and sold by private equity firms. For years, the private equity industry has stirred controversy when its investments in healthcare, retail, and restaurants have gone south. When criticized, the industry usually defends itself by pointing to workers' retirement pensions and saying they grow faster because they're invested in PE. But does PE really get the best returns of any investment? Business Insider Pro