▁ ▁Test ing ▁predictions ▁of ▁mathematical ▁econom ics ▁Phil os opher ▁Karl ▁Po pper ▁discussed ▁the ▁scientific ▁standing ▁of ▁econom ics ▁in ▁the ▁ 1 9 4 0 s ▁and ▁ 1 9 5 0 s . ▁He ▁argued ▁that ▁mathematical ▁econom ics ▁suffered ▁from ▁being ▁t aut ological . ▁In ▁other ▁words , ▁in so far ▁as ▁econom ics ▁became ▁a ▁mathematical ▁theory , ▁mathematical ▁econom ics ▁ceased ▁to ▁rely ▁on ▁empir ical ▁ref ut ation ▁ ▁but ▁rather ▁re lied ▁on ▁mathematical ▁proofs ▁and ▁dis proof . ▁According ▁to ▁Po pper , ▁ ▁f als ifiable ▁assumptions ▁can ▁be ▁tested ▁by ▁experiment ▁and ▁observation ▁while ▁unf als ifiable ▁assumptions ▁can ▁be ▁expl ored ▁mathemat ically ▁for ▁their ▁consequences ▁and ▁for ▁their ▁consist ency ▁with ▁other ▁assumptions . ▁ ▁Sh aring ▁Po pper ' s ▁concerns ▁about ▁assumptions ▁in ▁econom ics ▁generally , ▁and ▁not ▁just ▁mathematical ▁econom ics , ▁Mil ton ▁Fried man ▁declared ▁that ▁" all ▁assumptions ▁are ▁un real istic ". ▁ ▁Fried man ▁proposed ▁jud ging ▁economic ▁models ▁by ▁their ▁predict ive ▁performance ▁rather ▁than ▁by ▁the ▁match ▁between ▁their ▁assumptions ▁and ▁reality . ▁ ▁Mathemat ical ▁econom ics ▁as ▁a ▁form ▁of ▁pure ▁mathematics ▁ ▁Consider ing ▁mathematical ▁econom ics , ▁J . M . ▁Ke yn es ▁wrote ▁in ▁The ▁General ▁Theory : ▁ ▁Def ense ▁of ▁mathematical ▁econom ics ▁In ▁response ▁to ▁these ▁critic isms , ▁Paul ▁Samuel son ▁argued ▁that ▁mathematics ▁is ▁a ▁language , ▁repeating ▁a ▁th esis ▁of ▁Jos iah ▁Will ard