▁of ▁labour ▁and ▁capital ▁among ▁branches ▁of ▁industry , ▁in ▁other ▁words ▁that ▁capital ▁and ▁labour ▁can ▁be ▁trad ed ▁and ▁shift ed ▁around ▁fairly ▁freely , ▁with ▁the ▁aid ▁of ▁better ▁transport ▁and ▁communication ▁systems . ▁ ▁In ▁Capital , ▁Volume ▁I , ▁Marx ▁largely ▁ignored ▁price ▁fl uct u ations ▁for ▁the ▁given ▁inputs ▁and ▁outputs ▁of ▁production . ▁He ▁assumed ▁that ▁the ▁prices ▁of ▁comm od ities ▁were ▁equal ▁to ▁their ▁values . ▁There ▁were , ▁however , ▁three ▁main ▁reasons ▁for ▁this ▁simpl ification : ▁ ▁Whether ▁or ▁not ▁comm od ities ▁used ▁or ▁produced ▁trad ed ▁for ▁a ▁bit ▁more , ▁or ▁a ▁bit ▁less , ▁than ▁their ▁soci ally ▁average ▁value , ▁made ▁no ▁substantial ▁difference ▁to ▁the ▁capital ist ▁relationships ▁of ▁the ▁production ▁process ▁which ▁he ▁sought ▁to ▁analyze . ▁ ▁Marx ▁aim ed ▁to ▁show , ▁that ▁even ▁if ▁all ▁comm od ities ▁trad ed ▁exactly ▁at ▁their ▁value ▁( equal ▁exchange ), ▁and ▁regardless ▁of ▁short - term ▁price ▁fl uct u ations , ▁capital ists ▁could ▁still ▁make ▁money ▁from ▁production , ▁since , ▁in ▁the ▁normal ▁business ▁situation , ▁workers ▁always ▁created ▁more ▁value ▁for ▁their ▁employ ers ▁than ▁was ▁represented ▁by ▁the ▁total ▁w age ▁bill . ▁If ▁that ▁wasn ' t ▁the ▁case , ▁capital ists ▁would ▁be ▁defeated ▁by ▁market ▁fl uct u ations ▁very ▁quickly . ▁Econom ic ▁explo itation ▁was , ▁therefore , ▁not ▁simply ▁a ▁matter ▁of ▁unf air ly ▁short - ch anging ▁people ▁in