'create a workfile
wfcreate u 10000

'set the seed
rndseed 12345

'generate simulated data series
!alpha = 0
!beta1 = 1.5
series x1 = @runif(0,1)
series e = @rnorm '@rchisq(1) 'paper seems to be using chi-squared distribution
series y = @exp(!alpha+!beta1*log(x1)+e)
x1 = @recode(x1<0.1,0,x1)
series lx1 = @recode(x1>0,log(x1),x1)

'comparison of the best practice with the proposed solution
equation eqols.ls(cov=hac) log(y) c lx1 x1=0
equation eqglm.glm(family=poisson,cov=hac) y c lx1 x1=0
equation eqgmm.gmm(instwgt=hac, gmmiter=1) log(y+exp(c(2)*lx1+c(3)*(x1=0)))-(c(2)*lx1+c(3)*(x1=0))-c(1) @ lx1 x1=0