Which it is, as an academic subject. Which again is not that difficult to comprehend. What's hard is accepting it. As Jussaume argues, the perception of risk among individuals varies wildly according to their sense of control. But many other factors affect and confuse that perception, also.
People tend to either exaggerate low risk or ignore it completely.
How a subject is framed, or presented, can greatly affect their perception of risk. So it's not only the irrational consumer who suffers from misperception. When this perceptual problem is applied as policy, the analysis can get very tricky. When people in Colorado got sick last year, the guilty E. coli was traced back to hamburger from Hudson Foods. The USDA recalled five million pounds, then 25 million pounds, essentially putting Hudson Foods out of business.