Unemployment  develops,  that  is  to  say,  because
people  want  the  moon: — men  cannot  be  employed
when  the  object  of  desire  (i.e.  money)  is  something
which  cannot  be  produced  and  the  demand  for
which  cannot  be  readily  choked  off.  There  is  no
remedy  but  to  persuade  the  public  that  green  cheese
is  practically  the  same  thing  and  to  have  a  green
cheese  factory  (i.e.  a  central  bank)  under  public
control.
It  is  interesting  to  notice  that  the  characteristic
which  has  been  traditionally  supposed  to  render
gold  especially  suitable  for  use  as  the  standard  of
value,  namely,  its  inelasticity  of  supply,  turns  out
to  be  precisely  the  characteristic  which  is  at  the
bottom  of  the  trouble.
Our  conclusion  can  be  stated  in  the  most  general
form  (taking  the  propensity  to  consume  as  given)
as  follows.  No  further  increase  in  the  rate  of  in-
vestment is  possible  when  the  greatest  amongst  the
own-rates  o(  own-interest  of  all  available  assets
is  equal  to  the  greatest  amongst  the  marginal  effi-
ciencies o(  all  assets,  measured  in  terms  of  the  asset
whose  own-rate  of  own-interest  is  greatest.
In  a  position  of  full  employment  this  condition
is  necessarih  satisfied.  But  it  may  also  be  satisfied
before  full  employment  is  reached,  if  there  exists
some  asset,  having  zero  (or  relativel)  small)  elastici-
ties of  production  and  substitution."'  whose  rate  of
interest  declines  more  slow  h .  as  output  increases,
than  the  marginal  efficiencies  of  capital-assets  meas-
ured in  the  terms  of  it.
IV

We  have  shown  above  that  for  a  commodity  to

be  the  standard  of  value  is  not  a  sufficient  condition
for  that  commodity's  rate  of  interest  to  be  the  signif-

2.  A  zero  elasticity  is  a  more  stringent  condition  than
is  necessarily  required.
