Measurement method

R & D investment

ln (Research and development costs + 1)

Interest expense ratio

ln (Interest expense/Total fixed assets)

Current assets ratio

ln (Total current assets/Total assets)

Per capita output

ln (Industrial production value of the year/Total employee at the end of the year)

Debt ratio

ln (Total Liabilities/Total assets)

Long-term debt ratio

ln (Total long-term liabilities/Total assets + 1)

Business age

Present year- Year of establishment

Capital intensity

ln (Total fixed assets/Total employee at the end of the year)