▁a ▁transaction ▁in ▁the ▁secondary ▁market ▁because ▁neither ▁of ▁them ▁produced ▁the ▁sculpt ure . ▁ ▁It ▁is ▁more ▁complicated ▁for ▁econom ists , ▁then , ▁to ▁capture ▁these ▁transactions ▁in ▁their ▁data . ▁ ▁Compar ative ▁advantage ▁is ▁also ▁more ▁difficult ▁to ▁pin point ▁in ▁the ▁case ▁of ▁cultural ▁goods . ▁▁ ▁There ▁is ▁a ▁certain ▁degree ▁of ▁cultural ▁national ism ▁of ▁art , ▁making ▁some ▁nations ▁rel uct ant ▁to ▁part ▁with ▁their ▁cultural ▁property . ▁ ▁Additionally , ▁relative ▁advantage ▁cannot ▁simply ▁be ▁calculated ▁by ▁the ▁marg inal ▁cost ▁of ▁producing ▁a ▁unit ▁of ▁art , ▁since ▁a est h etic ▁value ▁plays ▁so ▁heavily ▁into ▁its ▁price . ▁ ▁Trade ▁theory ▁demonstr ates ▁how ▁much ▁and ▁at ▁what ▁price ▁countries ▁trade ▁goods ▁if ▁they ▁have ▁different ▁end ow ments ▁or ▁different ▁prefer ences . ▁ ▁But ▁this ▁model ▁is ▁not ▁very ▁useful ▁because ▁of ▁ret ent ive ▁national ism : ▁a ▁country ▁that ▁is ▁relatively ▁less ▁end owed ▁with ▁art - produ cing ▁resources ▁will ▁not ▁stop ▁producing ▁simply ▁because ▁they ▁can ▁import ▁art ▁from ▁abroad ▁at ▁che aper ▁prices . ▁ ▁Det erm ination ▁of ▁prices ▁ ▁Trad itional ▁trade ▁theory ▁tre ats ▁art ▁as ▁a ▁hom ogen ous , ▁non - d iffer enti ated ▁good , ▁which ▁is ▁where ▁it ▁fails ▁to ▁reli ably ▁predict ▁trade ▁tr ends . ▁Un ique ▁art ▁is ▁val ued ▁precisely ▁because ▁of ▁its ▁uniqu eness . ▁ ▁Since ▁each ▁piece ▁of ▁art ▁is ▁different , ▁and ▁because ▁each ▁piece ▁does