Using loop for generate and replace

[David Dahlgren]

Hi,
I would like to make a loop were I create 20 new variables (stretching 2001-2020) using two constrictions with if. Bellow I make an example of how I would do it manually variable by variable. How can I do this more efficient?

gen newvariable1 = 0
replace new variable1 = 1 if variable==1 & year2001
gen newvariable2 = 0
replace new variable2 = 1 if variable==1 & year2002

gen newvariable3 = 0
replace new variable3 = 1 if variable==1 & year2003

gen newvariable4 = 0
replace new variable4 = 1 if variable==1 & year2004

gen newvariable5 = 0
replace new variable5 = 1 if variable==1 & year2005


/David

[Nick Cox]

I guess that year2001 is a typo for year == 2001, and so forth.

forval j = 1/20 { 
    gen better_name_needed`j' = variable == 1 & year == (2000 + `j')  
}

and

tab year if variable == 1, gen(better_name_needed)

are some of the quicker ways to do this. Here better_name_needed is a hint not to use newvar as a stub.

See e.g. https://www.stata.com/support/faqs/d...rue-and-false/ or https://www.stata-journal.com/articl...article=dm0099 for the point that indicator variables can be generated directly in one line.