INTERNATIONAL  TRADE  153

prices  would  fall  in  Germany  and  rise  in
England,  and  when  the  point  was  reached  at
which  the  prices  of  both  commodities  were
the  same  in  both  countries  there  would  be
no  advantage  in  sending  either  commodity
abroad,  because  when  sent  abroad  it  would
realise  no  more  than  it  would  fetch  at  home.
Hence  our  first  proposition  is  proved  that
comparative  values  must  differ  if  there  is  to
be  permanent  trade  between  countries.
The  second  proposition  to  be  enunciated  and
defended  is  two-sided  :  that  when  a  position
of  equilibrium  in  international  trade  is  reached
(a)  comparative  values  will  be  identical,  and
(b)  in  a  given  period  the  total  value  that  a
country  exports  will  equal  the  total  value
that  it  imports,  apart  from  cost  of  transport
which  we  shall  continue  to  ignore  to  expedite
our  argument.  The  prior  section  of  this
proposition  is  in  reality  a  corollary  from  the
first  proposition  laid  down,  for  it  is  apparent
that  so  long  as  a  difference  between  comparative ­
  values  remains  there  will  be  a  disposition
on  the  part  of  business  men  in  both  countries
to  increase  or  decrease  their  exports.  The
existence  of  a  difference  between  comparative
values  is  sufficient  evidence  of  the  profitableness ­
  of  their  doing  so.  At  first,  however,
one  may  feel  a  difficulty  in  realizing  how