▁find ▁a ▁continu ation ▁in ▁modern ▁cart el ▁theory . ▁ ▁D iffer ences ▁between ▁the ▁two ▁cart el ▁theories ▁ ▁Modern ▁cart el ▁theory ▁points ▁out ▁- ▁much ▁more ▁committed ▁than ▁the ▁classical ▁one ▁- ▁to ▁the ▁det r iment al ▁consequences ▁of ▁a ▁lack ▁of ▁competition ▁that ▁leads ▁to ▁over pr icing , ▁mis al location ▁of ▁capital ▁and ▁slow ing ▁down ▁of ▁technical ▁progress ▁in ▁the ▁economy . ▁In ▁this ▁context , ▁this ▁doctrine ▁has ▁helped ▁to ▁develop ▁the ▁parad ig m ▁of ▁market ▁failure , ▁which ▁must ▁be ▁avoided ▁by ▁means ▁of ▁an ▁appropriate ▁competition ▁policy . ▁On ▁the ▁other ▁hand , ▁the ▁dis adv antages ▁of ▁un rest rained ▁competition ▁- ▁such ▁as ▁unnecessary ▁bulk ▁goods ▁transport , ▁unnecessary ▁advert ising ▁for ▁m ature ▁goods , ▁brand ▁sales ▁strateg ies ▁- ▁are ▁highlight ed ▁in ▁the ▁classic ▁cart el ▁theory . ▁Thus , ▁these ▁two ▁directions ▁of ▁cart el ▁studies ▁feature ▁conflic ting , ▁mut ually ▁exclusive ▁economic ▁concepts ▁and ▁neither ▁of ▁them ▁can ▁ide ally ▁solve ▁the ▁fundamental ▁problem ▁of ▁entrepr ene ur ial ▁competition . ▁ ▁Term in olog ically , ▁classical ▁cart el ▁theory ▁has ▁yield ed ▁s oph istic ated ▁definitions ▁and ▁class ifications ▁of ▁cart el ▁types ▁that ▁were ▁based ▁on ▁material ▁institution al ▁criteria . ▁By ▁contrast , ▁modern ▁cart el ▁theory ▁is ▁essentially ▁norm ative . ▁Its ▁specific ▁termin ology ▁depends ▁on ▁the ▁respective ▁competition ▁law , ▁its ▁national ▁version ▁of ▁the ▁cart el ▁ban ▁and ▁exem ptions ▁for ▁useful ▁cart