下面是我用gmm估计做的动态面板估计，但是工具变量好像加的不对，错误报告如下：版主能不能帮忙解答下
. gmm((patent-{a}*L.patent)*exp({b1}*L.lrd+{b2}*L.lsize+{b3}*L.lr+{b4}*d+{b5}*L.
> lprof)/exp({b1}*lrd+{b2}*lsize+{b3}*lr+{b4}*d+{b5}*lprof)-(L.patent-{a}*L2.pat
> ent)),xtinstruments( lsize,lags(0/.)) xtinstruments(lr,lags(0/.)) xtinstrument
> s( lrd,lags(0/.)) xtinstruments( lprof,lags(0/.) ) onestep

错误：must specify winitial(xt xtspec) or winitial(matname)
with XT-style instruments
r(498);