Skip to Main Content
Table 8. 
Regression results from the Total OA Articles hurdle models for Natural Resources and Conservation, Physical and Mathematical Sciences, and Social and Behavioral Sciences, showing the count data component (Total OA articles > 0) and the zero count component (Total OA articles = 0)
 Nat. Res. & ConservationPhys. & Math. Sci.Soc. & Behav. Sci.
βSig.e^βStd. Err.βSig.e^βStd. Err.βSig.e^βStd. Err.
  Positive Count Component Positive Count Component Positive Count Component 
Gender is Male 0.011   1.011 0.026 0.042 ** 1.043 0.015 0.016   1.017 0.015 
Institution is Public −0.071 * 0.932 0.033 −0.099 *** 0.906 0.014 −0.060 *** 0.942 0.016 
Institution is AAU Member 0.106 *** 1.112 0.024 0.287 *** 1.332 0.013 0.219 *** 1.245 0.015 
Years Since Degree −0.004 ** 0.996 0.001 −0.005 *** 0.995 0.001 0.003 ** 1.003 0.001 
Professorial Rank 0.023   1.024 0.021 0.098 *** 1.103 0.011 −0.079 *** 0.924 0.013 
Has Won Research Grants 0.235 *** 1.265 0.024 0.350 *** 1.419 0.013 0.341 *** 1.407 0.017 
Total Article Count 0.038 *** 1.039 0.001 0.021 *** 1.021 0.000 0.064 *** 1.066 0.001 
Log(θ) 1.369 *** 3.932 0.042 0.209 *** 1.232 0.015 0.581 *** 1.788 0.024 
Constant 1.141 *** 3.131 0.051 1.222 *** 3.393 0.026 0.391 *** 1.478 0.029 
  Zero Hurdle Component Zero Hurdle Component Zero Hurdle Component 
Gender is Male 0.040   1.041 0.139 0.070   1.072 0.052 0.111 *** 1.118 0.033 
Institution is Public 0.140   1.150 0.224 −0.078   0.925 0.050 −0.139 *** 0.870 0.036 
Institution is AAU Member −0.060   0.942 0.139 0.388 *** 1.474 0.046 0.428 *** 1.534 0.033 
Years Since Degree −0.009   0.991 0.007 −0.016 *** 0.984 0.002 −0.009 *** 0.991 0.002 
Professorial Rank −0.128   0.880 0.110 0.090 * 1.094 0.039 0.000   1.000 0.030 
Has Won Research Grants 0.408 * 1.504 0.181 0.427 *** 1.533 0.053 0.476 *** 1.610 0.055 
Total Article Count 0.442 *** 1.555 0.021 0.519 *** 1.680 0.009 0.342 *** 1.408 0.005 
Constant −0.870 ** 0.419 0.296 −1.105 *** 0.331 0.087 −1.469 *** 0.230 0.060 
Observations 3,913       30,415       28,228       
Log-likelihood −9,894       −87,620       −51,720       
 Nat. Res. & ConservationPhys. & Math. Sci.Soc. & Behav. Sci.
βSig.e^βStd. Err.βSig.e^βStd. Err.βSig.e^βStd. Err.
  Positive Count Component Positive Count Component Positive Count Component 
Gender is Male 0.011   1.011 0.026 0.042 ** 1.043 0.015 0.016   1.017 0.015 
Institution is Public −0.071 * 0.932 0.033 −0.099 *** 0.906 0.014 −0.060 *** 0.942 0.016 
Institution is AAU Member 0.106 *** 1.112 0.024 0.287 *** 1.332 0.013 0.219 *** 1.245 0.015 
Years Since Degree −0.004 ** 0.996 0.001 −0.005 *** 0.995 0.001 0.003 ** 1.003 0.001 
Professorial Rank 0.023   1.024 0.021 0.098 *** 1.103 0.011 −0.079 *** 0.924 0.013 
Has Won Research Grants 0.235 *** 1.265 0.024 0.350 *** 1.419 0.013 0.341 *** 1.407 0.017 
Total Article Count 0.038 *** 1.039 0.001 0.021 *** 1.021 0.000 0.064 *** 1.066 0.001 
Log(θ) 1.369 *** 3.932 0.042 0.209 *** 1.232 0.015 0.581 *** 1.788 0.024 
Constant 1.141 *** 3.131 0.051 1.222 *** 3.393 0.026 0.391 *** 1.478 0.029 
  Zero Hurdle Component Zero Hurdle Component Zero Hurdle Component 
Gender is Male 0.040   1.041 0.139 0.070   1.072 0.052 0.111 *** 1.118 0.033 
Institution is Public 0.140   1.150 0.224 −0.078   0.925 0.050 −0.139 *** 0.870 0.036 
Institution is AAU Member −0.060   0.942 0.139 0.388 *** 1.474 0.046 0.428 *** 1.534 0.033 
Years Since Degree −0.009   0.991 0.007 −0.016 *** 0.984 0.002 −0.009 *** 0.991 0.002 
Professorial Rank −0.128   0.880 0.110 0.090 * 1.094 0.039 0.000   1.000 0.030 
Has Won Research Grants 0.408 * 1.504 0.181 0.427 *** 1.533 0.053 0.476 *** 1.610 0.055 
Total Article Count 0.442 *** 1.555 0.021 0.519 *** 1.680 0.009 0.342 *** 1.408 0.005 
Constant −0.870 ** 0.419 0.296 −1.105 *** 0.331 0.087 −1.469 *** 0.230 0.060 
Observations 3,913       30,415       28,228       
Log-likelihood −9,894       −87,620       −51,720       

* p < 0.05; ** p < 0.01; *** p < 0.001.

Close Modal

or Create an Account

Close Modal
Close Modal