▁term ▁very ▁uns atisf actory ▁for ▁the ▁purposes ▁of ▁a ▁caus al ▁analysis , ▁which ▁ought ▁to ▁be ▁exact . ▁Nevertheless ▁these ▁difficulties ▁are ▁right ly ▁regarded ▁as ▁‘ con und rum s ’ . ▁They ▁are ▁‘ p ure ly ▁theoretical ’ ▁in ▁the ▁sense ▁that ▁they ▁never ▁per plex , ▁or ▁indeed ▁enter ▁in ▁any ▁way ▁into , ▁business ▁dec isions ▁and ▁have ▁no ▁relev ance ▁to ▁the ▁caus al ▁sequence ▁of ▁economic ▁events , ▁which ▁are ▁clear - cut ▁and ▁determin ate ▁in ▁spite ▁of ▁the ▁quant itative ▁ind et erm in acy ▁of ▁these ▁concepts . ▁It ▁is ▁natural , ▁therefore , ▁to ▁conclude ▁that ▁they ▁not ▁only ▁lack ▁precision ▁but ▁are ▁unnecessary . ▁Obviously ▁our ▁quant itative ▁analysis ▁must ▁be ▁expressed ▁without ▁using ▁any ▁quant it atively ▁vague ▁expressions . ▁And , ▁indeed , ▁as ▁soon ▁as ▁one ▁makes ▁the ▁attempt , ▁it ▁becomes ▁clear , ▁as ▁I ▁hope ▁to ▁show , ▁that ▁one ▁can ▁get ▁on ▁much ▁better ▁without ▁them . ▁ ▁The ▁units ▁of ▁the ▁General ▁Theory ▁Ke yn es ▁used ▁a ▁sub script ▁w   ▁( not ▁used ▁by ▁this ▁article ) ▁to ▁indicate ▁values ▁in ▁w age ▁units , ▁but ▁was ▁im prec ise ▁and ▁incons istent . ▁In ▁the ▁words ▁of ▁Brad ford ▁and ▁Har court : ▁On ▁balance , ▁it ▁appears ▁that ▁for ▁all ▁the ▁ing enu ity ▁and ▁subt le ty ▁of ▁Ke yn es ’ s ▁reasoning ▁on ▁the ▁question ▁of ▁units , ▁he ▁ultimately ▁failed ▁to ▁apply ▁it ▁consist