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.
Notes: Figures present the precision-recall frontiers for methods commonly used in historical linking. The data are male birth certificates linked to the 1940 Census.
