open abdata.gdt

list X = w k ys                  # list of explanatory variables

### built-in method
panel n const X --fixed-effects

### recentering "by hand"
depvar = n - pmean(n) + mean(n)  # redefine the dependent variable
list indepvars = const
loop foreach i X
    # redefine the explanatory variables
    x_$i = $i - pmean($i) + mean($i)
    indepvars += x_$i
endloop
ols depvar indepvars             # perform estimation

### using centered dummies
list C = dummify(unit)           # create the unit dummies
smpl n X --no-missing            # adjust to perform centering correctly
list D = stdize(C, -1)           # center the unit dummies
ols n const X D                  # perform estimation