Table 3 Variable definitions and measurement methods.

X1: Political Pressure from the Central Government

Measured by the number of environmental accountability cases transferred to each provincial-level administrative region during the first round of central environmental inspections.

Publicly available inspection reports from the Ministry of Ecology and Environment

Raw data are calibrated using the direct calibration method: Raw percentage data are calibrated using the direct calibration method: fully in (≥top 5th percentile nationwide), maximum ambiguity (median), and fully out (≤bottom 5th percentile nationwide).

X2: The Legislative Stock for Supervising Administrative Enforcement

Degree of legislative completeness for administrative enforcement supervision at the provincial level (0–1 scale), assigned based on six legislative models: 0 = No local legislation or government regulations; 0.2 = Non-specialized local legislation only; 0.4 = Specialized local government regulations only; 0.6 = Both non-specialized local legislation and specialized local government regulations; 0.8 = Specialized local legislation only; 1 = Both specialized local legislation and specialized local government regulations.

Peking University Law Database.

Values are directly assigned based on legislative model classification.

X3: The Share of the Secondary Sector

The share of the secondary sector in GDP (%, averaged from 2017 to 2022).

China Statistical Yearbook (2018–2023).

Raw percentage data are calibrated using the direct calibration method: fully in (≥ top 5th percentile nationwide), maximum ambiguity (median), and fully out (≤bottom 5th percentile nationwide).

X4: Resource Allocation for Environmental Enforcement

Public fiscal expenditure on energy conservation and environmental protection (10,000 RMB, averaged from 2017 to 2022) at the provincial level.

China Statistical Yearbook (2018–2023).

Raw data are calibrated using the direct calibration method: fully in (≥top 5th percentile nationwide), maximum ambiguity (median), and fully out (≤ bottom 5th percentile nationwide).

X5: Public Demand for Environmental Quality

Per capita GDP (10,000 RMB, averaged from 2017 to 2022) at the provincial level.

China Statistical Yearbook (2018–2023).

Raw data are calibrated using the direct calibration method: fully in (≥ top 5th percentile nationwide), maximum ambiguity (median), and fully out (≤ bottom 5th percentile nationwide).