我嘗試跟從那位教授的範例,可是并不能成功進行指令,有那位高手可以給我看看有什麼問題嗎?
下面是STATA中的顯示:

. ssc install pescadf
checking pescadf consistency and verifying not already installed...
all files already exist and are up to date.
. use http://fmwww.bc.edu/ec-p/data/hayashi/sheston91.dta,clear
(Penn World Table Mark 5, R. Summers / A. Heston, 1991)
. tsset
       panel variable:  country (strongly balanced)
        time variable:  year, 1960 to 1985
                delta:  1 year
. pescadf rgdppc if country>116 & country<140, lags(2)
unrecognized command:  / invalid command name
r(199);