- inter ference ▁is ▁soci ally ▁optimal . ▁ ▁The ▁basic ▁model ▁is ▁a ▁variation ▁on ▁the ▁Stack el berg – C our not ▁" le ader ▁and ▁follow er " ▁du opol y ▁game . ▁Alternatively , ▁the ▁model ▁can ▁be ▁port rayed ▁in ▁game ▁the or etic ▁terms ▁as ▁initially ▁a ▁game ▁with ▁multiple ▁Nash ▁equilib ria , ▁with ▁government ▁having ▁the ▁cap ability ▁of ▁affect ing ▁the ▁pay offs ▁to ▁switch ▁to ▁a ▁game ▁with ▁just ▁one ▁equilibrium . ▁Although ▁it ▁is ▁possible ▁for ▁the ▁national ▁government ▁to ▁increase ▁a ▁country ' s ▁w elf are ▁in ▁the ▁model ▁through ▁export ▁subs id ies , ▁the ▁policy ▁is ▁of ▁begg ar ▁thy ▁neighbor ▁type . ▁This ▁also ▁means ▁that ▁if ▁all ▁govern ments ▁simultaneously ▁attempt ▁to ▁follow ▁the ▁policy ▁pres cription ▁of ▁the ▁model , ▁all ▁countries ▁would ▁wind ▁up ▁worse ▁off . ▁ ▁The ▁model ▁was ▁part ▁of ▁the ▁" New ▁Trade ▁Theory " ▁that ▁was ▁developed ▁in ▁the ▁late ▁ 1 9 7 0 s ▁and ▁early ▁ 1 9 8 0 s , ▁which ▁incorpor ated ▁then ▁recent ▁develop ments ▁from ▁literature ▁on ▁industrial ▁organization ▁into ▁theories ▁of ▁international ▁trade . ▁In ▁particular , ▁like ▁in ▁many ▁other ▁New ▁Trade ▁Theory ▁models , ▁econom ies ▁of ▁scale ▁( in ▁this ▁case , ▁in ▁the ▁form ▁of ▁fixed ▁entry ▁costs ) ▁play ▁an ▁important ▁role ▁in ▁the ▁Br ander – S pen cer ▁model . ▁ ▁Entry ▁game ▁version ▁ ▁A ▁simplified ▁version ▁of ▁the ▁model ▁was ▁popular