[R] clustered standarderrors using design package

Please help, I have a strange problem. I've got a balanced panel data set. I use dummy variable regression and I've got results with lm function. summary(lm(y ~ post + t19961 + t19962 + t19963 + t19964 + t19971 + t19972 + t19973 + t19974 + t19981+factor( id))) The problem is that I would like

Re: [R] clustered standarderrors using design package

Anders Eklund wrote: Please help, I have a strange problem. I've got a balanced panel data set. I use dummy variable regression and I've got results with lm function. summary(lm(y ~ post + t19961 + t19962 + t19963 + t19964 + t19971 + t19972 + t19973 + t19974 + t19981+factor( id)))