▁independent ▁of ▁each ▁other . ▁Both ▁are ▁determined ▁by ▁their ▁own ▁factors . ▁From ▁this ▁Mal th us ▁generates ▁the ▁idea ▁of ▁" effect ive ▁demand ," ▁which ▁later ▁becomes ▁popular ▁in ▁Ke yn esian ▁econom ics . ▁" Effect ive ▁demand " ▁iter ates ▁that ▁consum ers ▁purchase ▁more ▁or ▁less ▁of ▁a ▁good ▁depending ▁on ▁the ▁price ▁a ▁firm ▁charges ▁for ▁it . ▁Mal th us ' ▁idea ▁suggests ▁that ▁the ▁amount ▁of ▁goods ▁supplied ▁may ▁be ▁a ▁result ▁of ▁the ▁demand . ▁ ▁Furthermore , ▁Mal th us ▁arg ues ▁that ▁the ▁economy ▁tends ▁to ▁move ▁towards ▁re cess ions ▁because ▁product ivity ▁often ▁grows ▁more ▁quickly ▁than ▁demand . ▁Mal th us ▁suggests ▁increasing ▁government ▁sp ending ▁and ▁private ▁invest ment ▁on ▁lux uries ▁to ▁c ure ▁re cess ions . ▁This ▁idea ▁firm ly ▁goes ▁against ▁the ▁notion ▁that ▁Ric ardo ▁and ▁Say ▁hold ▁that ▁the ▁economy ▁will ▁fix ▁itself ▁through ▁demand . ▁ ▁Second ▁Edition ▁ ▁A ▁second ▁edition ▁of ▁Mal th us ' ▁Princi ples ▁of ▁Political ▁Econom y ▁was ▁published ▁in ▁ 1 8 3 6 . ▁After ▁the ▁first ▁version ' s ▁publication , ▁Adam ▁Smith ▁develop s ▁the ▁idea ▁that ▁an ▁object ' s ▁inher ent ▁value ▁is ▁related ▁to ▁the ▁labor ▁that ▁went ▁into ▁its ▁creation . ▁Additionally , ▁Smith ▁creates ▁the ▁notion ▁that ▁a ▁good ' s ▁price ▁also ▁moves ▁in ▁the ▁direction ▁of ▁the ▁price ▁of ▁other ▁comm od ities . ▁After ▁careful ▁cont empl ation , ▁Mal th us