MONOPOLY

101

Local  discrimination  is  practised  when  a
thing  is  sold  for  one  price  in  one  locality,
and  another  price  in  another  locality.  International ­
  discriminations  are  common,  and
even  intra-national  discriminations  are  to  be
found.  In  the  case  of  the  latter  the  difference
between  the  two  prices  cannot  be  more  than
the  cost  of  carriage  from  the  one  place  to
the  other  if  the  thing  can  be  transported
after  being  sold  ;  as,  for  example,  gas,
electricity,  and  transportation  itself  cannot.
In  the  case  of  international  discriminations,
however,  where  tariffs  protect  the  home
market,  the  difference  between  the  two  prices
may  amount  to  as  much  as  cost  of  carriage
and  the  import  duty  on  re-entry.
A  trade  discrimination  means  charging
more  for  a  thing  when  it  is  used  for  one
purpose,  that  is  in  one  trade,  than  when
it  is  used  for  another  purpose,  that  is  in
another  trade.  Generally  trade  discrimination
is  not  feasible  because  of  the  difficulty  of
discovering  to  what  use  the  purchaser  intends
putting  the  commodity  ;  but  there  remain
some  important  instances  in  which  differential
charges  of  this  kind  are  not  only  possible  but
have  become  the  common  rule.  The  best
example  is  to  be  found  in  railway  freight
rates.  The  railways  sell  transportation  and