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Showing posts from November, 2023

Sum up and create new variable with STATA

Following are examples of how to create new variables in Stata using the gen (short for generate) and egen commands: To create a new variable (e.g., newvar ) and set its value to 0 , use: gen newvar = 0 To create a new variable (e.g., total ) from the transformation of existing variables (e.g., the sum of v1 , v2 , v3 , and v4 ), use: gen total = v1 + v2 + v3 + v4 Alternatively, use egen with the built-in rowtotal option: egen total = rowtotal(v1 v2 v3 v4) Note: The egen command treats missing values as 0 . To create a variable (e.g., avg ) that stores the average of four variables (e.g., v1 , v2 , v3 , and v4 ), use: gen avg = (v1 + v2 + v3 + v4) / 4 Note: Use the / (slash) to denote division and an * (asterisk) for multiplication. Alternatively, use egen with the built-in rowmean option: egen avg = rowmean(v1 v2 v3 v4) Stata also lets you take advantage of built-in functions for variable transformations. For example, to take the natura