No DNA test needed
In the 1990s, states began allowing unmarried fathers to declare paternity at the hospital when a child was born. Many places saw an immediate impact, with paternity rates increasing. The chart below shows the ratio of paternity establishments to new births for states that enacted the policy in 1995 and 1999, periods that are marked by the triangles. (Note: paternity establishments include fathers of children up to 18 years old.)
 
Source: author data