How do you calculate the average drop-out/entry rate for a sample?

[Michael Duarte Goncalves]

Hi everyone,

I would like to compute the average rate of dropouts, let say for my monthly file of January 2021. Does anyone have an idea on how to do that, please?

I define a 'drop-out' as a household that leaves the sample. So they don't stay from 1 to 31 January 2021.
On the same vein, I define an "entry" as a household that enters in my sample on any day in January.

From what I browsed "manually", it seems to me to have much more entries than drop-outs, but my dataset is big and I would like to check it by other means, please.

Here is my small -dataex- for January 2021 file:

* Example generated by -dataex-. For more info, type help dataex
clear
input long id double date_contract_start float date_elec_consumption double date_contract_end float(h_0 h_1 h_2)
1001 21701 22281 22431 .179 .113 .149
1001 21701 22282 22431 .115 .181 .114
1001 21701 22283 22431 .177 .115 .147
1001 21701 22284 22431 .136 .123 .144
1001 21701 22285 22431 .146 .119 .177
end
format %td date_contract_start
format %td date_elec_consumption
format %td date_contract_end

The ID "1001" shown above has observations up to 31 January 2021.

Below is a household that enters my January 2021 sample later (on 29 January 2023):

* Example generated by -dataex-. For more info, type help dataex
clear
input long id double date_contract_start float date_elec_consumption double date_contract_end float(h_0 h_1 h_2)
869251 22309 22309 22431 0 0 0
869251 22309 22310 22431 0 0 0
869251 22309 22311 22431 0 0 0
end
format %td date_contract_start
format %td date_elec_consumption
format %td date_contract_end

Thank you in advance for your help!
Best,

Michael