Figure 2.
Response rates according to: (A) Unwillingness score (p =1 × 10 −10 ); (B) Additive score (p =3 × 10 −9 ). Results are expressed as mean response rates for each class, T-bars represent the 95% confidence interval.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.