From the U.S. Bureau of the Census:
The Census Bureau is pleased to announce a new opportunity for you to participate in research that will lead to improving the 2020 Census and other surveys that the Census Bureau collects. If you are interested in occasionally completing a short, online survey for the Census Bureau, please click [this link]. The Census Bureau will occasionally email you an invitation to complete a survey for one of our research projects. We will tell you the topic of the survey, and we’ll tell you how long it will take you to complete it. Your responses will be kept completely confidential, and you can always decide not to participate in a survey. After each study is completed, if you are interested, we will email you a link to a report of the findings that you helped to generate.