▁Un ions ▁Labor ▁un ions ▁have ▁been ▁called ▁co er ci ve ▁mon opol ies ▁which ▁keep ▁w ages ▁rates ▁higher ▁than ▁they ▁would ▁otherwise ▁be ▁if ▁individuals ▁competed ▁with ▁each ▁other ▁for ▁w ages . ▁Econom ists ▁who ▁believe ▁this ▁to ▁be ▁the ▁case ▁refer ▁to ▁this ▁as ▁a ▁mon opol y ▁w age . ▁( He ery , ▁Edmund ; ▁No on , ▁Mike ▁( 2 0 0 2 ). ▁A ▁Dictionary ▁of ▁Human ▁Resources ▁Management . ▁Oxford ▁University ▁Press . ▁p .   2 2 5 ) ▁ ▁Foot notes ▁ 1 . ▁L ys ander ▁Spo on er ▁started ▁the ▁commer cially ▁successful ▁American ▁Let ter ▁Mail ▁Company ▁in ▁order ▁to ▁comp ete ▁with ▁the ▁United ▁States ▁Post ▁Office ▁by ▁providing ▁lower ▁rates . ▁He ▁was ▁successfully ▁challeng ed ▁by ▁the ▁U . S . ▁government ▁and ▁exha usted ▁his ▁resources ▁trying ▁to ▁defend ▁what ▁he ▁believed ▁to ▁be ▁his ▁right ▁to ▁comp ete . ▁▁ 2 . ▁For ▁about ▁six ▁months , ▁Thomas ▁Gib b ons ▁and ▁Corn el ius ▁V ander b ilt ▁operated ▁a ▁steam bo at ▁with ▁lower ▁far es ▁in ▁def iance ▁of ▁the ▁law . ▁Gib b ons ▁successfully ▁took ▁his ▁case ▁to ▁the ▁United ▁States ▁Supreme ▁Court . ▁The ▁Court ▁ruled ▁in ▁Gib b ons ▁v . ▁Og den ▁that ▁the ▁state - g overn ment - gr anted ▁mon opol y , ▁which ▁conducted ▁some ▁service ▁between ▁New ▁York ▁and ▁New ▁Jersey , ▁was ▁an ▁un const itution al ▁viol ation