The tax on medical devices that is part of the US Affordable Care Act will harm companies and American workers, writes Henry Miller from Stanford University and the Competitive Enterprise Institute in an op-ed at The Wall Street Journal. The 2.3 percent tax is slated to go into effect at the end of the year. "This tax is especially pernicious because it is assessed on sales, not profits," Miller says, describing a hypothetical situation in which a medical device company with $1 million in sales would be taxed $23,000, even if its profit was $100,000. Miller says companies are already taking defensive precautions in anticipation of the tax, like announcing layoffs. "We need to create a more nurturing entrepreneurial climate, one in which ingenuity and innovation are rewarded, not penalized," he adds.