The effect of perceived and assessed knowledge of climate change on public policy concerns: An empirical comparison

Knowledge is essential for evaluating risk and mitigating its influence through policy. The Knowledge Deficit Model (KDM) suggests that experts have knowledge that the public does not and that this knowledge deficit makes it difficult for the public to evaluate risk properly. Recent studies of KDM have been unable to find evidence of this expectation. We believe these examinations may have incorrectly measured knowledge. There are two approaches to measuring the public's knowledge on an issue: (1) subjective perceptions of one's knowledge and (2) objective assessment of one's knowledge. Scientific knowledge, defined as one's assessed understanding of an issue, is very different from one's subjective, perceived knowledge. We examine individual risk perceptions of climate change to determine the extent to which measurement errors of knowledge may have affected previous studies of KDM. Our findings suggest that subjective measures of knowledge are poorly capturing scientific knowledge. Our findings also suggest that using scientific measures of knowledge produces results that support KDM.