Hello everyone.
I am using Stata 14. I employed 2SLS estimation strategy with IV approach. I am using 3 IVs (distance to flood at village/cluster level, slope of cluster and distance if household to water source) and clustering the clustered standard error at enumeration block/cluster level. Moreover, i am using district fixed effects.
The issue is when i use the district fix effects i get this big warning message. How to resolve this if i have to use the fix effects at district level. Other control variables did not create any issue. I am new to state and don't know much about the models and statistics.
ivreg2 child_haz (imp_sanitation = dist_wtrsource_min hubdist_flood1 slope) i.ch_age_mo child_female i.child_brthsiz ch_food_div head_age head_gender head_edu mo_age mo_educ mo_working woman_height rural hh_size unimp_water wtr_treat ch_feces_disp livestock i.wealthq i.district, cluster(v_cluster)
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Weak identification test (Cragg-Donald Wald F statistic): 175.058
(Kleibergen-Paap rk Wald F statistic): 132.605
Stock-Yogo weak ID test critical values: 5% maximal IV relative bias 13.91
10% maximal IV relative bias 9.08
20% maximal IV relative bias 6.46
30% maximal IV relative bias 5.39
10% maximal IV size 22.30
15% maximal IV size 12.83
20% maximal IV size 9.54
25% maximal IV size 7.80
Source: Stock-Yogo (2005). Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
overidentification statistic not reported, and standard errors and
model tests should be interpreted with caution.
Possible causes:
number of clusters insufficient to calculate robust covariance matrix
singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
I am using Stata 14. I employed 2SLS estimation strategy with IV approach. I am using 3 IVs (distance to flood at village/cluster level, slope of cluster and distance if household to water source) and clustering the clustered standard error at enumeration block/cluster level. Moreover, i am using district fixed effects.
The issue is when i use the district fix effects i get this big warning message. How to resolve this if i have to use the fix effects at district level. Other control variables did not create any issue. I am new to state and don't know much about the models and statistics.
ivreg2 child_haz (imp_sanitation = dist_wtrsource_min hubdist_flood1 slope) i.ch_age_mo child_female i.child_brthsiz ch_food_div head_age head_gender head_edu mo_age mo_educ mo_working woman_height rural hh_size unimp_water wtr_treat ch_feces_disp livestock i.wealthq i.district, cluster(v_cluster)
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic): 175.058
(Kleibergen-Paap rk Wald F statistic): 132.605
Stock-Yogo weak ID test critical values: 5% maximal IV relative bias 13.91
10% maximal IV relative bias 9.08
20% maximal IV relative bias 6.46
30% maximal IV relative bias 5.39
10% maximal IV size 22.30
15% maximal IV size 12.83
20% maximal IV size 9.54
25% maximal IV size 7.80
Source: Stock-Yogo (2005). Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
overidentification statistic not reported, and standard errors and
model tests should be interpreted with caution.
Possible causes:
number of clusters insufficient to calculate robust covariance matrix
singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
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