然而问题来了,当我使用tab命令时,可以识别 y(专利申请数)有非常多的0值。
而当我对其回归时,-zinp 没有显示0值,右上角的 Zero obs =0
· tab apply_number1
apply_number1 |
r1 | Freq. Percent Cum.
------------+-----------------------------------
0 | 1,350 31.27 31.27
1 | 109 2.52 33.80
2 | 115 2.66 36.46
3 | 139 3.22 39.68
4 | 113 2.62 42.30
5 | 129 2.99 45.29
. zinb apply_number1 pre_* current post_* T GDP RD ,inf( ln_income ln_RD L2_sp )
Zero-inflated negative binomial regression Number of obs = 2,532
Inflation model: logit Nonzero obs = 2,532
Zero obs = 0
LR chi2(4) = 58.99
Log likelihood = -11706.99 Prob > chi2 = 0.0000
* Example generated by -dataex-. For more info, type help dataex
clear
input double(id year apply_number1)
1 2009 0
1 2010 0
1 2011 0
1 2012 0
1 2013 0
1 2014 0
1 2015 0
1 2016 0
1 2017 0
1 2018 0
1 2019 0
1 2020 0
2 2009 4
2 2010 6
2 2011 10
2 2012 22
2 2013 11
2 2014 8
2 2015 57
2 2016 51
2 2017 148
2 2018 60
2 2019 70
2 2020 35
3 2009 10
3 2010 0
3 2011 10
3 2012 11
3 2013 44
3 2014 3
3 2015 7
3 2016 0
3 2017 2
3 2018 8
3 2019 0
3 2020 24
4 2009 0
4 2010 0
4 2011 0
4 2012 0
4 2013 1
4 2014 11
4 2015 3
4 2016 21
4 2017 8
4 2018 4
4 2019 30
4 2020 44
5 2009 5
5 2010 2
5 2011 3
5 2012 5
5 2013 13
5 2014 3
5 2015 10
5 2016 9
5 2017 18
5 2018 12
5 2019 8
5 2020 8
6 2009 8
6 2010 0
6 2011 9
6 2012 11
6 2013 6
6 2014 8
6 2015 10
6 2016 5
6 2017 1
6 2018 4
6 2019 4
6 2020 7
end
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