Hello,

I am working with a dataset where I have identified 7,286 observations. These observations belong to different households. Now, for these observations, using the Household they belong to, I want to identify the Household Head from another dataset. The other dataset has 42,151 observations who are Household Heads. I only want to keep the observations in the second set who belong to the same Household as the observations from the first set.

I have tried using the merge function but I keep receiving an error due to the mismatch in unique observations. I am guessing since the variable from the first dataset has only 7,286 observations which is much lesser than the 42,151 observations in the second dataset where I want to merge the variable to.

I will put an example of the first dataset below:

The first column/variable 'id' is the unique identification number for the individuals.
The second column/variable "HHBASE" represents the unique Household Base ID which remains unchanged for the two datasets.

Now, in my other dataset, I want to keep only observations with the following HHBASE values:

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input str12 id double HHBASE
"101020102010" 1010201020
"10102010205"  1010201020
"10102010206"  1010201020
"10102010207"  1010201020
"10102010304"  1010201030
"10102010305"  1010201030
"10102010306"  1010201030
"10102010307"  1010201030
"10102011304"  1010201130
"10102011305"  1010201130
"10102011306"  1010201130
"10102011307"  1010201130
"10102011702"  1010201170
"10102011703"  1010201170
"10102011704"  1010201170
"10102011705"  1010201170
"10102012007"  1010201200
"10102020103"  1010202010
"10102020104"  1010202010
"10102020105"  1010202010
"10102020403"  1010202040
"10102020405"  1010202040
"10102020505"  1010202050
"10102021205"  1010202120
"10102021206"  1010202120
"10102030105"  1010203010
"10102030106"  1010203010
"10102030107"  1010203010
"10102030207"  1010203020
"10102030208"  1010203020
"10102030209"  1010203020
"10102030406"  1010203040
"10102030505"  1010203050
"10102030506"  1010203050
"101020306010" 1010203060
"101020306013" 1010203060
"101020306014" 1010203060
"10102030605"  1010203060
"10102030606"  1010203060
"10102030706"  1010203070
"10102031305"  1010203130
"10102031306"  1010203130
"10102031307"  1010203130
"10102031309"  1010203130
"101020403011" 1010204030
"101020403012" 1010204030
"10102040305"  1010204030
"10102040306"  1010204030
"10102040604"  1010204060
"10102040605"  1010204060
"10102040606"  1010204060
"10102040607"  1010204060
"10102040608"  1010204060
"10102040904"  1010204090
"10102040906"  1010204090
"10102040907"  1010204090
"101020413018" 1010204130
"101020413019" 1010204130
"10102041406"  1010204140
"10102041407"  1010204140
"10102041506"  1010204150
"10102042003"  1010204200
"10102051204"  1010205120
"10102051205"  1010205120
"10102051206"  1010205120
"10102051207"  1010205120
"10102051503"  1010205150
"10102051505"  1010205150
"10102051506"  1010205150
"10102051507"  1010205150
"10102051906"  1010205190
"10102051907"  1010205190
"10102051908"  1010205190
"10102060603"  1010206060
"10102060604"  1010206060
"10102060703"  1010206070
"10102060704"  1010206070
"10102060803"  1010206080
"10102060804"  1010206080
"10102060805"  1010206080
"10102060806"  1010206080
"10102061005"  1010206100
"10102061006"  1010206100
"10102070606"  1010207060
"10102070607"  1010207060
"10102070608"  1010207060
"10102071003"  1010207100
"10102071004"  1010207100
"10102071104"  1010207110
"10102071105"  1010207110
"10102071106"  1010207110
"10102071107"  1010207110
"10102080603"  1010208060
"10102080604"  1010208060
"10102080605"  1010208060
"10102080703"  1010208070
"10102080704"  1010208070
"10102080705"  1010208070
"101020808010" 1010208080
"101020808011" 1010208080
end

Your guidance will be of great help. Thanks!