手册上的：
Global and local macro names
What we say next is an exceedingly fine point: global macro names that begin with an underscore are really local macros; this is why local macro names can have only 31 characters. The local command is formally defined as equivalent to global . Thus the following are equivalent:
local x                             global  _x
local i=1                          global  _i=1
local name "Bill"             global  _name "Bill"
local fmt : format myvar global  _fmt : format myvar
local 3 `2'                        global  _3 $ 2

猜两个吧
pulic choice的创始人Gordon Tullock
健康经济学的神级人物Grossman