Scott Adler and John Wilkerson:
bq. In the 111th Congress, HR 3590 as introduced was titled the Service Members Home Ownership TAX Act of 2009. As enacted, HR 3590 was titled the Patient Protection and Affordable Care Act, otherwise known as Obamacare. The legislative history of HR 3590 is unusual but by no means unique. It illustrates a widely appreciated but rarely studied point: bills evolve as they move through the legislative process. They pick up and shed policy provisions that can range from relatively small adjustments in language to complete bills (in the case of omnibus legislation).
bq. The figure [below] illustrates a new text-based approach to systematically tracing the progress of policy ideas or provisions (as opposed to bills) in legislation. We use text reuse methods from computer science (think plagiarism detection) to trace similar language wherever it appears in legislation. Figure 1 is based on a comparison of section texts in introduced bills in the 111th Congress to section texts found in the enacted version of the Affordable Care Act (ACA). A substantial number of ACA sections match sections in bills sponsored by other lawmakers (of both parties). One of these bills (HR 3692) became law after the ACA’s enactment, but apparently not before some of its original provisions found their way into the ACA.
Here’s the figure: