M24****9720 2021-05-17 12:08 开发者_开发问答这个我还真不知道，对不起😭D32****945
I\'m pretty new to Stata. I have a set of observation开发者_运维技巧s of the form \"CountryGDPYear\". I want to create a new variable GDP1960, which gives the GDP in 1960 of each country for each yea
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