Temporal patterns in biosecurity-related regulation before and after Loper Bright

The 2024 Supreme Court decision in Loper Bright Enterprises v. Raimondo ended Chevron deference, reshaping the relationship between federal agencies and the judiciary. This study examines the impact of this legal shift on U.S. biosecurity governance, specifically focusing on the regulation of synthetic nucleic acid technologies.

We employed a multi-period observational design to analyze regulatory issuance counts across 26 federal agencies using six sentinel search terms: biosecurity, biotechnology, bioeconomy, synthetic nucleic acid, gene synthesis, and nucleic acid screening. Primary data were drawn from Regulations.gov website searches; a parallel Federal Register API dataset was constructed to enable rolling-window placebo analysis, administration transition analysis partitioned at 20 January 2025, and a matched certiorari-period baseline reconstruction. Analyses were designed to assess whether observed patterns are consistent with a Loper Bright effect, while accounting for the concurrent administration transition and baseline variability in regulatory output.

Total biosecurity-relevant regulatory activity declined by 21.5% in the year following Loper Bright, even as overall federal regulatory output increased by 2.0%. This decline was not fully explained by administration policy preferences, as biosecurity activity increased by 12.2% from the Trump to Biden administrations, though the concurrent transition to a new administration in January 2025 represents a confound the observational design cannot fully disentangle. Domains with low statutory clarity, such as gene synthesis (-87.5%), showed the most severe contractions, more extreme than 99% of historical year-over-year fluctuations, while those with clear mandates, like the bioeconomy (+200%), remained resilient.

The findings suggest that statutory clarity is strongly correlated with regulatory resilience. The post-Loper landscape has created significant governance gaps in novel technical domains where federal departments or agencies previously relied on interpretive authority. Legislative intervention may be required to provide the "clear statutory authority" necessary to maintain a robust national biosecurity posture.