Table 1 Evaluation indicator system of tourism environmental efficiency.

From: Structural characteristics and influencing factors of a spatial correlation network for tourism environmental efficiency in China

Type

Primary indicator

Secondary indicator

Input variables

Resource input

Scale of tourism enterprises (total number of A-level tourist attractions, travel agencies and star hotels)

Capital investment

Investment in tourism fixed assets (total investment in fixed assets of A-level tourist attractions, travel agencies and star hotels)

Total investment in environmental pollution control

Labor input

Number of tourism employees

Output variables

Expected output

Total tourism income

Unexpected output

Tourism carbon emissions (the sum of carbon emissions from tourism transportation, tourism accommodation and tourism activities)