Data Pooling

[anne jagdberg]

Hey @all,
sorry, I know it is not the first asking about data pooling but previous posts were not helpful to me because unfortuenately I did not really understand it.

Following problem for me a stata newbie:

I am using a survey dataset with quarterly data from several countries of 25 years.

What I would like to do for my analyses is to pool the quarterly survey data from all the countries to yearly data and in the second step across all countries. It is among other variables mostly about finding out prevalence rates of cancer and hours of sports (past 7-days).

Maybe someone can help me by explaining how I can pool the quarterly survey data to yearly data?

Thank you very much in advance

[Andrew Musau]

You will most likely need to use the collapse command, but there are different ways to aggregate the data and what makes sense should be known to you. If, e.g., hours are quarterly counts, then the annual count is just the summation of hours across quarters in a year. For rates, it may make sense to see how they are computed and then use annual values to compute the annual rates as opposed to aggregating the quarterly rates. There are a number of aggregation methods including averaging and taking the first or last values.

collapse (sum) hours, by(country year)

[anne jagdberg]

Thank you very much for the quick reply!!
I will try that on go on