Hello,
I found that several hundred observations in my data are dropped if I use reghdfe compared to when I use xtreg. It says it drops singleton observations, but I cannot really understand why these observations are singleton observations and thus dropped. They are not dropped if I use xtreg. This means the sample sizes are different when I use reghdfe and xtreg. These dropped observations are not limited to the cases where there is only one observation (per person). Is there anyone who knows how to idenfity why each observation is singleton observation or not? I really want to understand why the sample size gets smaller when I use reghdfe compared to xtreg.
Thank you so much!!
I found that several hundred observations in my data are dropped if I use reghdfe compared to when I use xtreg. It says it drops singleton observations, but I cannot really understand why these observations are singleton observations and thus dropped. They are not dropped if I use xtreg. This means the sample sizes are different when I use reghdfe and xtreg. These dropped observations are not limited to the cases where there is only one observation (per person). Is there anyone who knows how to idenfity why each observation is singleton observation or not? I really want to understand why the sample size gets smaller when I use reghdfe compared to xtreg.
Thank you so much!!
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