Writing a Loop structure in Stata for Matching study samples

[Kaddijatou Manneh]

Hi Statalist,
I am new to Stata. I have dataset containing two groups of firms; one group raised 1 type of equity whilst the other group group raised another type of equity. The raises of firms occurred in different years starting in 2011 through to 2018. I want to match these two groups of firms based on continuous variables a b and c but I want the matched firms to have raised equity in the same year. How do I go about? What is the syntax for such an operation? Thanks in advance

[David Radwin]

The following is from the help file for psmatch2 (Leuven and Sianesi, SSC):

Matching within strata

    The following code illustrates how to match within exact cells and then calculate the average effect for the whole
    population.

        g att = .
        egen g = group(groupvars)
        levels g, local(gr)
        qui foreach j of local gr {
                psmatch2 treatvar varlist if g==`j', out(outvar)
                replace att = r(att) if  g==`j'
        }
        sum att