search for: avg_ham_r

Displaying 1 result from an estimated 1 matches for "avg_ham_r".

2013 Jan 13
1
R error: system is computationally singular when building GMM model
Dear, I built the generalized method of moments model to estimate the sales rank in the bookstore using plm package in R. The equation is: data1.gmm <- pgmm(dynformula(lnsales_rank ~ ln_price + avg_ham_rate + avg_spam_rate + num_of_ham+ num_of_spam + ship_code2 +ship_code3 +ship_code4+ ship_code5+ ship_code6 + ship_ code7, lag = list(0, 0, 0, 0,0,0,0,0,0,0,0,0), log =FALSE), data=data, effect = "individual", model = "twosteps", transformation = "ld",gmm.inst = ~ ln_pri...