ner ▁cont ends ▁that ▁distributions ▁of ▁potential ▁power ▁may ▁vary ▁from ▁multip olar ▁to ▁h eg em onic ; ▁and ▁different ▁international ▁trad ing ▁structures ▁are ▁made ▁of ▁either ▁of ▁these . ▁The ▁key ▁to ▁this ▁argument ▁is ▁that ▁a ▁h eg em onic ▁distribution ▁of ▁potential ▁economic ▁power ▁is ▁likely ▁to ▁result ▁in ▁an ▁open ▁trad ing ▁system . ▁Since ▁states ▁act ▁to ▁maxim ize ▁their ▁aggregate ▁economic ▁utility , ▁maximum ▁global ▁w elf are ▁is ▁achieved ▁under ▁free ▁trade . ▁ ▁Ne oc lass ical ▁trade ▁theory ▁pos its ▁that ▁the ▁greater ▁the ▁degree ▁of ▁open ness ▁in ▁the ▁international ▁trad ing ▁system , ▁the ▁greater ▁the ▁level ▁of ▁aggregate ▁economic ▁income . ▁ ▁The oret ical ▁pers pect ives ▁ ▁Real ism ▁ ▁Robert ▁Gil pin ▁and ▁Stephen ▁K ras ner ▁are ▁advoc ates ▁of ▁the ▁real ist ▁tradition , ▁which ▁emphas ises ▁the ▁h eg em onic ▁system . ▁The ▁h eg em onic ▁system ▁cont ends ▁that ▁there ▁are ▁states ▁that ▁are ▁much ▁larger ▁and ▁more ▁developed ▁than ▁their ▁trad ing ▁partners ▁and ▁therefore , ▁the ▁costs ▁and ▁benefits ▁of ▁open ness ▁are ▁not ▁symmet rical ▁for ▁all ▁members ▁of ▁the ▁system . ▁K ras ner ▁( 1 9 7 6 ) ▁cont ends ▁that ▁the ▁h eg em onic ▁state ▁will ▁have ▁a ▁preference ▁for ▁an ▁open ▁structure ▁because ▁it ▁will ▁increase ▁its ▁aggregate ▁national ▁income ▁and ▁ ▁power . ▁ ▁Real ism ▁emphas izes ▁states ' ▁dem ands ▁for ▁power ▁and ▁security . ▁Military ▁force ▁is