▁them . ▁This ▁value ▁exists ▁and ▁pers ists ▁quite ▁independently ▁of ▁fl uct u ating ▁prices ▁in ▁mark ets . ▁Although ▁they ▁are ▁connected , ▁the ▁value ▁relationships ▁between ▁labour - products ▁and ▁price ▁relationships ▁can ▁vary ▁independently ▁of ▁each ▁other , ▁within ▁certain ▁limits . ▁A ▁price ▁can ▁be ▁attached ▁to ▁almost ▁any ▁object , ▁but ▁this ▁does ▁not ▁automatically ▁mean ▁that ▁the ▁object ▁also ▁has ▁a ▁value ▁in ▁Marx ' s ▁sense ▁of ▁being ▁the ▁product ▁of ▁labour . ▁ ▁The ▁field ▁of ▁application ▁of ▁the ▁law ▁of ▁value ▁is ▁limited ▁to ▁new ▁output ▁by ▁produ cers ▁of ▁trad ed , ▁reprodu cible ▁labour - products , ▁although ▁it ▁might ▁indirect ly ▁influence ▁trade ▁in ▁other ▁goods ▁or ▁assets ▁( for ▁example , ▁the ▁value ▁of ▁a ▁second - hand ▁good ▁may ▁be ▁related ▁to ▁a ▁newly ▁produced ▁good ▁of ▁the ▁same ▁type ). ▁Thus , ▁the ▁law ▁does ▁not ▁apply ▁to ▁all ▁goods , ▁services ▁or ▁assets ▁in ▁an ▁economy , ▁and ▁it ▁does ▁not ▁rule ▁the ▁whole ▁economy . ▁In ▁modern ▁Marx ism , ▁the ▁law ▁of ▁value ▁is ▁often ▁equ ated ▁with ▁" market ▁economy ", ▁but ▁that ▁was ▁not ▁Marx ' s ▁own ▁idea . ▁R ather , ▁it ▁limits , ▁regul ates ▁and ▁const ra ins ▁the ▁trade ▁in ▁products . ▁Sim ply ▁put , ▁the ▁soci ally ▁necessary ▁labour ▁requirements ▁set ▁limits ▁for ▁the ▁movements ▁of ▁product ▁prices . ▁ ▁Primary ▁products ▁are ▁a ▁special ▁case , ▁which ▁Marx ▁discuss es ▁in ▁his ▁theory ▁of