forvalues i = 1(1)50 {
    set obs 100
    gen x`i' =_n
    gen u`i' = invnorm(uniform())*sigma
    gen y`i'= beta0 + beta1*x`i'+u`i'      
    quietly reg y`i' x`i'
    matrix b`i' = e(b)
    matrix list b`i'
    matrix rmse`i'= e(rmse)
    matrix list rmse`i'
}

matrix b0 = (0,0)
matrix rmse0 = (0)