Dear Statalists,

I am working on treatment effects of foreign acquisition on firms' productivity, in which I use propensity score matching to match firms that have similar characteristics (one is acquired and the other stay in domestic hand) and see how their productivity differs.

I have questions over the command in the guideline for psmatch2:

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

Could you please explain what does it mean when the curly bracket "{" is used and why does, after the bracket, psmatch2 move to another line but not stay at the same line, also why does the closing bracket stay alone at another line?

Thank you so much for your concerns.