# Table 4 The first stage estimation using the instrumental variable

Estimation model Estimation with “Employed” as the dependent variable
Ordinary least squares coefficient Probit marginal effect
Instrumental variable
A bus stop in the village or neighborhood 0.079 (0.017)*** 0.106 (0.025)***
Other explanatory variables
Household annual income in natural log 0.019 (0.004)*** 0.041 (0.010)***
Ethnic minority (wife and/or husband) −0.064 (0.024)*** −0.100 (0.036)***
Age 0.027 (0.009)*** 0.055 (0.015)***
Age squared −0.001 (0.001)*** −0.001 (0.0002)***
Married −0.025 (0.056) −0.085 (0.102)
The first child is a son 0.007 (0.015) 0.013 (0.023)
Wife has siblings −0.025 (0.0436) −0.031 (0.072)
Husband has siblings −0.019 (0.035) −0.001 (0.055)
Smoking −0.061 (0.037)* −0.197 (0.071)**
Drinking alcohol 0.024 (0.026) 0.086 (0.044)**
Health insurance −0.014 (0.017) 0.023 (0.026)
Education
Less than primary school (reference)
Primary school 0.026 (0.024) 0.084 (0.048)***
Lower middle school 0.122 (0.023)*** 0.233 (0.041)***
Upper middle school 0.136 (0.029)*** 0.274 (0.051)***
Technologic school 0.148 (0.039)*** 0.512 (0.047)***
College 0.109 (0.041)*** 0.677 (0.023)***
Health status
Excellent (reference)
Good −0.059 (0.023)*** −0.082 (0.035)***
Fair −0.046 (0.026)* −0.053 (0.037)
Poor −0.140 (0.039)*** −0.214 (0.045)***
Province
Heilongjiang (reference)
Liaoning 0.141 (0.028)*** 0.259 (0.052)***
Jiangsu 0.309 (0.033)*** 0.444 (0.048)***
Shandong 0.204 (0.030)*** 0.354 (0.050)***
Henan 0.019 (0.023) 0.024 (0.050)
Hubei 0.152 (0.031)*** 0.236 (0.057)***
Hunan 0.032 (0.027) 0.046 (0.054)
Guangxi 0.240 (0.035)*** 0.420 (0.052)***
Guizhou 0.160 (0.030)*** 0.305 (0.057)***
Village or neighborhood population (in 1000) −0.002 (0.001)** −0.003 (0.002)
Han nationality allowed to have two children if the first child is female −0.033 (0.017)* −0.041 (0.027)
Receiving a subsidy if having one child 0.039 (0.019)** 0.064 (0.030)**
Urban 0.306 (0.026)*** 0.491 (0.032)***
Constant −0.507 (0.196)*** N/A
R squared 0.378   N/A
Tests of the first stage1
Test of excluded instruments
F statistic 22.520 *** N/A
Underidentification tests
Kleibergen-Paap rk LM statistic 22.690 *** N/A
Kleibergen-Paap rk Wald statistic 22.960 *** N/A
Weak identification test
Kleibergen-Paap Wald rk F statistic2 22.600 * N/A
1. N/A not applicable.
2. * significant at the 10% level; ** significant at the 5% level; *** significant at the 1% level.
3. 1 Tests are obtained using preferred number of children as the dependent variable in two-stage least squares estimation.
4. 2 Only 10% maximal IV size of Stock-Yogo weak ID test critical value is available.