Explained variable

Patent

the numbers of invention patent authoriztion

R & D

Ln (the research and found investment/operation income + 1)

Explanatory variable

treat

The dummy variable = treatment * post

Control variables

ROA

Net income/Total asset at the end of the year

Tobin Q

Total Market Value of Firm/Total Asset at the end of the year

Lev

Finacial leverage = total debt/total asset at the end of the year

Bm

Book to market ratio = equity/market cap

Fs

First shareholding/Total equity

Sale

Sales expenditure/Operation income at the end of year

opgr

Operation income growth rate = (Operation income at this year − Operation income at last year)/Operation income at last year

Gov

Government subsidy/Operation income at the end of year

Ms

Management shareholding/Total equity

lnsalary

Ln (salary of directors and executive management + 1)

inder

The numbers of independent directors/Total directors

age

Company registration age

size

Ln (total asset at the end of the year + 1)