Xtset. That seems to match the set-up here. Xtset distid year panel variable.
Description prepares a panel dataset for lag operations. The lag function in R is simply lag varnumlags. The democracy index for Trinidad and Tobago in 1995 is 1.
Year 1992 to 1998 delta.
May 04 2019 On Unix-like operating systems the xset command changes user settings for the X Window System. You can use xset to change the basic characteristics of your GUI including the way your mouse and keyboard behave and which display to use for your X session. Xtset distid year panel variable. It can be any variable of your own concocting so long as it takes on only integer values.
