Hierarchical Environmental Supervision, Recorded Enforcement, and Spatial Reach: Evidence from China’s Environmental Protection Interviews

Higher-level environmental supervision is intended to strengthen local implementation, but its influence need not extend across administrative boundaries. We examine whether China’s environmental protection interviews are associated with recorded enforcement activity in targeted jurisdictions and whether nearby associations support a horizontal-diffusion interpretation. Using a 2010–2019 balanced panel of 96 local administrative units, we estimate Poisson pseudo-maximum-likelihood (PPML) models for detected violations and firms with recorded violations. Spatial exposure is assessed using distance-based measures, province-by-year fixed effects, and adjacency diagnostics. Under the timing-clean specification, post-interview estimates are positive for both outcomes, with greater precision for detected violations. A clean-control stacked PPML analysis shows positive short-run estimates for detected violations, although pooled estimates are imprecise. An HonestDiD sensitivity analysis indicates that the first post-interview estimate is sensitive to deviations from parallel trends. Spatial associations are less stable across specifications and inference procedures. Overall, the results indicate a relatively consistent positive within-jurisdiction association rather than statistical robustness across all specifications. Because the sample reflects the available interview, enforcement, and geographic data rather than random sampling, the findings apply to the observed analytical sample.