This site provides estimates of U.S. climate change beliefs, risk perceptions, and policy preferences at the state and local levels - a new source of high-resolution data on public opinion that can inform national, state and local decision-making, policy, and education initiatives.
The estimates are derived from a statistical model using multilevel regression with post-stratification (MRP) on a large national survey dataset (n>13,000), along with demographic and geographic population characteristics.
The estimates were validated using three different methods.
- First, cross-validation analyses were conducted within the dataset. The dataset was divided into two sets of respondents, with one part used to run the model and the other kept aside for validation. The model estimates were then compared to the results of the set aside respondents to directly quantify the percentage of correct answers the model predicted. These cross-validation tests were repeated multiple times using different sample sizes and dividing the data in different ways.
- Second, the model estimates derived from the full dataset were compared to the results of independent, representative state- and city-level surveys conducted in California, Colorado, Ohio, Texas, San Francisco, and Columbus, Ohio in 2013. The mean absolute difference between model estimates and validation survey results was 2.9 percentage points (SD = 1.5) among the four states (CA, TX, OH, CO) and 3.6 percentage points (SD = 2.9) among the two metropolitan areas (Columbus, OH, and San Francisco, CA), well within the margins of error for the survey results alone (at a 95% confidence level). Estimates have also been validated internally through a series of technical simulations.
- Third, some model estimates were compared with third-party survey data collected by other researchers in previous years.
Margin of error estimates based on 95% confidence intervals using 199 bootstrap simulations indicate that the model is accurate to approximately ±5 percentage points at the state level, ±7 percentage points at the congressional district level and ±8 percentage points at the county level.
For more details, please see the online working paper: Howe, P., Mildenberger, M., Marlon, J.R., and Leiserowitz, A., “Geographic variation in opinions on climate change at state and local scales in the USA,” Nature Climate Change. DOI: 10.1038/nclimate2583.