Primary Submission Category: Reproductive health
Using sequence and cluster analysis to characterize U.S. state abortion policy trajectories from 1970 – 2014
Authors: Leah Koenig Lucia Pacca Rita Hamad Anusha Vable
Presenting Author: Leah Koenig*
Context and Objective: The 2022 Dobbs v. Jackson Women’s Health U.S. Supreme Court ended a federal protection for abortion. However, in recent years, states have increasingly implemented policies restricting and protecting abortion. We sought to characterize U.S. states’ abortion policy trajectories from 1970–2014.
Methods: We examined state policy data from all U.S. states from 1970 to 2014, and calculated a continuous index of abortion policy permissiveness. The index reflected the total number of protective abortion policies minus the number of restrictive abortion policies each year in each state, and was re-scaled from 0–1. We categorized this measure into quintiles ranging from very restrictive to very protective. We used sequence analysis to assess similarities between state abortion policy trajectories across the study period, and hierarchical clustering to group states with similar policy trajectories.
Results: State abortion policies were largely moderate or protective from the 1970s to 1990s. In several states, abortion policies grew more restrictive starting in the mid-1990s. We identified four abortion policy trajectory clusters: 1) states that were initially moderate and became restrictive in the 1990s, 2) states with initially protective policy environments that became restrictive in the 1990s, 3) states with protective policy environments that became restrictive in the mid-2000s, and 4) states with protective abortion policies throughout the study period. States that grew more restrictive (clusters 1-3) were predominantly located in the South and Midwest. Consistently protective states were most likely to be on the East and West coasts.
Conclusions: Even prior to the Dobbs decision, abortion policy had been growing more restrictive in many U.S. states, especially in the period between the mid-1990s and 2014. Abortion policies have become increasingly polarized over time. Reproductive autonomy is increasingly curtailed and determined by state of residence.