INTERNATIONAL  TRADE  163

view  of  theory  they  must  be  admitted.  They
are  special  cases  of  the  general  exception  to
the  doctrine  of  maximum  satisfaction,  to
which  Dr.  Marshall  has  drawn  attention.
The  doctrine  of  maximum  satisfaction,  according ­
  to  one  interpretation  of  it,  laid  it  down
that  under  competition  labour  and  capital
tend  to  be  devoted  to  their  most  profitable
uses  ;  but  Dr.  Marshall  has  pointed  out  that
this  generalisation  does  not  invariably  hold,
since,  for  example,  consumers’  surplus  could
be  increased  by  diverting  some  demand
from  things  produced  according  to  decreasing
returns  and  concentrating  it  instead  on  things
of  which  the  production  was  subject  to
increasing  returns.  The  explanation  of  this
curious  conclusion,  which,  of  course,  only
holds  when  other  things  are  equal,  is  that
under  competition  the  individual  acts  for
himself  and  consequently  leaves  out  of  his
calculations  that  the  price  of  some  things
would  fall  when  they  were  consumed  less
while  the  price  of  other  things  would  fall
when  they  were  consumed  more.  I  might
know  this  as  a  fact,  but  I  should  not  be
disposed  to  act  accordingly,  because  what  I
alone  did  would  have  very  little  effect  and
there  would  be  no  reason  to  suppose  that
others  would  follow  my  example  if  I  acted