Hence  two  methods  of  forecasting  the  future
increase  of  population. Either  we  may  observe
the  natural  increment  for  the  year  or  two  im-
mediately adjacent  to  1901,  and  assume  that
this  rate  will  remain  constant  for  the  following
decade  ;  or  we  may  assume  that  the  actual  rate
of  increase  for  the  decade  1891-1901  will  con-
tinue to  prevail  for  the  next  decade. A  variant
of  the  second  method  takes  account  of  the  fact
that  the  decennial  rate  of  increase  is  itself
greater  than  in  the  preceding  decade. The
average  of  the  results  obtained  by  these  three
methods  gives,  as  the  probable  population  in
1911,  over  36,400,000. The  Report  for  1911
records  36,075,269  as  the  actual  population  of
England  and  Wales  in  that  year. The  Economic
Journal  for  March  1911  contains  a  forecast  of
the  census  results  worked  out  by  two  students
of  statistics  from  the  recorded  births  and  deaths
and  Board  of  Trade  returns  of  emigrants  and
immigrants. The  figures  of  England  and  Wales
were  put  at  35,914,000,  or  about  half  a  million
less  than  tlie  estimate  given  above,  which  dis-
regards all  records  of  migration,  and  about
160,000  less  than  the  actual  figures. (2)
Density  of  the  population  and  habitations. The
density,  whether  expressed  as  the  mean  distance
between  individuals,  or  in  more  familiar  terms,
is  found  to  vary  from  place  to  place  and  to
increase  from  age  to  age. The  proportion
between  the  number  of  persons  and  the  number
of  habitations  is  less  variable. (3)  Sexes. The
excess  of  females  over  males  was  more  than  6
per  cent ;  a  slight  increase  over  the  preceding
decade. It  remained  at  that  figure  in  1901-
1911. (4)  Ages. At  this  stage  we  reach  less
solid  ground. The  returns  of  age  are  falsified
by  various  causes. Many  are  ignorant  and  put
down  a  round  number  at  random. The  very
old  desire  to  appear  still  older. Very  young
women  overstate  their  age  with  a  view  to
obtaining  employment ;  women  not  very  young
understate  their  age. From  this  double  cause
the  category  of  female  ages  between  fifteen  and
twenty -five  is  enormously  exaggerated. All
that  can  be  done  is  to  distribute  the  answers  in
periods  of  five  years  ;  and,  assuming  that  these
totals  are  correct,  to  determine  by  interpolation
the  numbers  for  each  year. (5)  Condition  as  to
marriage  or  civil  condition. 