156

POLITICAL  ECONOMY

it  is  not  inevitable  and  that  the  two  countries
might  go  on  trading  indefinitely  without  comparative ­
  costs  in  the  two  countries  becoming
the  same.  This  is  a  perfectly  valid  objection,
but  if  what  is  supposed  happens,  trade
would  continue  until  one  industry  had  disappeared ­
  in  one  of  the  countries  at  least.
Let  us  postulate  that  trade  does  reach  such  a
position  ;  that  England  sends  to  France
100,000  pieces  of  cotton  goods,  and  that  the
French  cotton  industry  disappears.  Let  it
be  that  the  costs  in  England  are  39s.  for  cotton
goods  and  20s.  for  wheat,  their  comparative
values  in  France  being  40s.  and  19s.  Then,
if  trade  still  increased  in  volume  the  value  of
cotton  goods  would  fall  in  France,  the  cost  of
wheat  rising,  let  us  suppose,  until  comparative
values  in  France  were  equal  to  comparative
costs  in  England,  or  until  farming  disappeared
in  England,  in  which  case  each  country  would
be  left  with  one  exporting  industry  only,
and  the  quantity  of  exchanging  between  the
two  countries  would  advance  until,  under  the
operation  of  the  law  of  diminishing  utility  in
both  countries,  comparative  values  would
become  the  same.  We  thus  see  that  a  limit
at  which  comparative  values  are  identical  is
inevitable.  To  this  theory  the  admission  of
more  countries  and  more  commodities,  and