▁may ▁be ▁higher ▁than ▁the ▁one ▁cent ▁per ▁ ounce ▁rate ▁most ▁commonly ▁used ▁in ▁U . S . ▁cities ." ▁A ▁ 2 0 1 9 ▁study ▁in ▁the ▁Qu arter ly ▁Journal ▁of ▁Econom ics ▁estimated ▁that ▁the ▁optimal ▁sugar ▁drink ▁tax ▁on ▁the ▁federal ▁level ▁in ▁the ▁U . S . ▁would ▁be ▁between ▁ 1 ▁and ▁ 2 . 1 ▁c ents ▁per ▁ ounce , ▁whereas ▁the ▁optimal ▁tax ▁on ▁the ▁city - level ▁was ▁ 6 0 % ▁lower ▁than ▁that ▁due ▁to ▁cross - border ▁sho pping . ▁ ▁External ities ▁as ▁a ▁r ationale ▁for ▁tax ation ▁The ▁purchase ▁of ▁sug ary ▁drink s ▁has ▁a ▁significant ▁negative ▁external ities ▁when ▁over - consum ption ▁causes ▁dise ases ▁like ▁ob es ity ▁and ▁type ▁ 2 ▁di ab etes . ▁Depending ▁on ▁the ▁national ▁health ▁care ▁system , ▁a ▁significant ▁portion ▁of ▁these ▁costs ▁are ▁paid ▁by ▁tax pay ers ▁or ▁ins urance ▁rate - pay ers ; ▁lost ▁product ivity ▁costs ▁are ▁paid ▁to ▁some ▁degree ▁by ▁employ ers . ▁ ▁Society ▁as ▁a ▁whole ▁could ▁be ▁worse ▁off ▁if ▁these ▁costs ▁are ▁calculated ▁to ▁be ▁greater ▁than ▁the ▁benefit ▁to ▁the ▁consum ers ▁of ▁s oda . ▁ ▁A ▁P ig ov ian ▁tax ▁like ▁a ▁sug ary ▁drink s ▁tax , ▁factors ▁these ▁external ities ▁into ▁the ▁price ▁of ▁the ▁be verage . ▁To ▁some ▁degree , ▁this ▁causes ▁people ▁who ▁over - cons ume ▁s oda ▁to ▁pay ▁for ▁health ▁care