[HPforGrownups] Why is Draco an only child?

[Alexis]

No: HPFGUIDX 127139

> Nice summary.  OTOH, this means that the system set up to encourage
> single births (of boys).  This is not good for a social system.  You
> need a spare in case something happens to the heir.  And you need at
> least some people produing girls or all your little boys  wind up
> with no one to marry.
> 
> Emma


The Brits practiced a "heir and spare" system, actually - second sons
having more of an opportunity to make a name of themselves than any
other child, with the obvious exception of the first born - so the
Malfoys having only one child is quite odd if one assumes that the WW
follows the same Brit system.  However, given that magic appears to be
able to reduce a great deal of childhood diseases, problems, ect., one
can also gather that the need for a spare is also greatly reduced. 
Therefore, if we follow the logic that the Malfoys entered into an
arranged marriage, they would do no more than their duty as far as
children are concerned.  Upon producing a reasonably sane heir and
having little need for a spare, especially considering the period of
time when that child would be born, the Malfoys just went on their
merry way and forgot about producing another child.

(Per the girls, the chance of producing a female is 2:4, so while the
social system may seem to encourage unusual ideals, there were,
obviously, enough girls coming along so that the male heirs didn't
have too much of a problem getting a wife.  Besides, this was a social
system that applied to only certain members of the populous, and on
top of that, if one was wealthy enough, a pretty woman of lower birth
may find herself a high-born husband, especially if he is in need of
money for the family coffers.)

Ignoring all that, though, it does seem as if the WW generally just
had small families, not surprising considering the correlation between
a more established society and a lower birth rate.  I would tend to go
for this somewhat boring explanation than the tie in with the British
upper class and their marital habits.

~Ali