What happens if you have variables in the Master Data which do not exist in the Using Data? The observations from the Using Data will be assigned missing values in those variables. Now you understand why we call the data in C:\more_observations.dta "Using Data". dta at the end of the filename), Stata assumes it's. In case no extension is specified (i.e no. This will add the observations from the file C:\more_observations.dta to the data in memory. It's syntax, in a simple form (for options not specified in this tutorial, you can always type help append in the command line in order to explore more about the command), goes like this:Īppend using "C:\more_observations" // (this is equivalent) The append command does what we called "vertical" combination. It will be clear why we use the word Using here. We will name the data in memory "Master Data" and the data to combine from the specified file "Using Data". All three of them combine the dataset currently in memory with data from a file you specify. There are three commands you should know if you want to combine datasets: append, merge and joinby. I will not elaborate on this matching too much. This is also problematic, since there is no unambiguous rule for the assignment of values from observations in one file to observations in the other file.
![merge stata merge stata](https://www.statadaily.com/wp-content/uploads/2010/10/combine_datasets_2.jpg)
"Horizontal" combination - This is the kind of combinations in which you want to add variables, and not observations.The command in Stata we will use is append. As long as the variables in the files are the same and the only thing you need to do is to add observations, this is vertical combination. Another possibility is that the data is separated according to different leagues, groups, etc. For instance, if you are working on a sports statistics project and you have data for players performance in four separate files, one for each year between 20.
![merge stata merge stata](https://csc.co.id/wp-content/uploads/2020/05/append2-350x189.jpg)
"Vertical" combination - You want to do this when you want to add observations from one file to another file.There are actually two main types of combinations:
Merge stata how to#
In this post I will try to elaborate a bit on how to make it work. Another case is when you have one dataset which is divided into multiple files.
![merge stata merge stata](https://i.ytimg.com/vi/_kX8KckR1HE/maxresdefault.jpg)
For example, if you want to analyze international growth, you might find economic indicators in a dataset of the World Bank, political indicators in think tanks such as Freedom House, and climate data in another dataset. In many cases, the data needed for the statistical analyses come from different sources.