RENT

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ment  for  the  agents  in  production  other  than
land  will,  therefore,  be  obtained  from  the
proceeds  of  a  quantity  of  produce  represented
by  the  marginal  returns,  multiplied  by  the
number  of  doses  applied.  When  there  is  a
surplus  produce  (that  is  produce  over  and
above  this  amount)  its  value  is  rent.
The  point  will  have  been  seized  already,  no
doubt,  that,  in  order  to  bring  in  the  element  of
situational  convenience,  the  doses  of  labour
and  capital  must  be  made  to  cover  the  cost  of
carrying  the  factors  in  production  to  the  land
and  produce  to  the  market.  For  the  sake
of  simplicity  we  are  leaving  out  specific
mention  of  these  costs,  and  for  the  same
reason  we  are  positing  that  the  produce  is
all  of  one  kind.  It  may  be  remarked,  however, ­
  that  when  the  produce  is  of  many  kinds
we  have  a  common  denominator  for  its
measurement  in  its  value  ;  and  that  the
principle  of  substitution,  which  naturally
settles  how  much  of  one  kind  of  produce  is
produced  and  how  much  of  another,  will
bring  it  about  that  the  proportion  of  the
different  kinds  of  produce  will  be  such  that,
in  view  of  the  price  of  each,  the  value  of  the
total  output  of  the  land  is  maximised.
Let  me  illustrate  our  simplified  case  with
figures  relating  to  a  given  piece  of  land  :—  “