▁of ▁his ▁own ▁product ▁to ▁get ▁a ▁different ▁product , ▁this ▁has ▁direct ▁consequences ▁for ▁the ▁additional ▁time ▁he ▁has ▁to ▁work ▁to ▁sust ain ▁himself ▁and ▁the ▁trad ing ▁of ▁his ▁product . ▁Over ▁time , ▁and ▁with ▁more ▁market ▁integration , ▁relatively ▁stable ▁values ▁for ▁products ▁are ▁established ▁in ▁accord ance ▁with ▁production ▁norm s ▁which ▁exist ▁independently ▁of ▁the ▁product ivity ▁of ▁individual ▁produ cers . ▁In ▁that ▁situation , ▁each ▁producer ▁has ▁to ▁adapt ▁his ▁own ▁production ▁to ▁those ▁soci ally ▁accepted ▁values , ▁the ▁average ▁terms ▁of ▁trade ▁for ▁products ▁vary ▁only ▁within ▁fairly ▁narrow ▁marg ins , ▁and ▁thus ▁produ cers ' ▁activities ▁fall ▁under ▁the ▁s way ▁of ▁the ▁law ▁of ▁value , ▁which ▁links ▁" the ▁economy ▁of ▁labour - time " ▁with ▁" the ▁economy ▁of ▁trade ". ▁Par ado x ically , ▁as ▁Marx ▁says , ▁the ▁more ▁that ▁the ▁produ cers ▁become ▁dependent ▁on ▁exchange , ▁the ▁more ▁exchange ▁appears ▁to ▁become ▁independent ▁of ▁them . ▁ ▁Product - mark ets ▁begin ▁to ▁operate ▁according ▁to ▁their ▁own ▁laws , ▁to ▁which ▁the ▁produ cers ▁can ▁only ▁adjust ▁themselves . ▁If ▁some ▁prices ▁go ▁up , ▁many ▁other ▁prices ▁will ▁go ▁up ▁as ▁well ▁because ▁people ▁have ▁to ▁cover ▁their ▁increased ▁costs . ▁If ▁some ▁prices ▁go ▁down , ▁many ▁other ▁prices ▁will ▁go ▁down ▁as ▁well ▁since ▁products ▁otherwise ▁fail ▁to ▁sell ▁when ▁che aper ▁alternatives ▁become ▁available , ▁but ▁no ▁individual ▁is ▁in ▁control ▁of ▁these ▁price ▁fl uct u