But as we have also seen previously, there are a number of serious problems with this free market approach. First, labor markets are not perfectly competitive and free. Employees do not have the kinds of free choices that the free market theory would require in order to attain optimal satisfactions. For example, risky jobs are often also the lowest-playing, jobs held by people with the fewest employment choices rather than the higher paying, freely chosen jobs that the market would suggest. Second, employees seldom if ever possess the kind of perfect information required by markets. If employees do not know the risks involved in a job, they will not be in a position to freely bargain for appropriate wages. This is a particular concern when we recognize that many risks faced in the workplace are in no sense obvious. An employee may understand the dangers of heavy machinery or a blast furnace, but few employees can know the toxicity or exposure levels of workplace chemicals or airborne contaminants.