  One of the outstanding problems of the dynamical evolution of the outer solar
system concerns the observed population ratio between the Oort Cloud (OC) and
the Scattered Disc (SD): observations suggest that this ratio lies between 100
and 1000 but simulations that produce these two reservoirs simultaneously
consistently yield a value of the order of 10. Here we stress that the
populations in the OC and SD are inferred from the observed fluxes of new Long
Period Comets (LPCs) and Jupiter-family comets (JFCs), brighter than some
reference total magnitude. However, the population ratio estimated in the
simulations of formation of the SD and OC refers to objects bigger than a given
size. There are multiple indications that LPCs are intrinsically brighter than
JFCs, i.e. an LPC is smaller than a JFC with the same total absolute magnitude.
When taking this into account we revise the SD/JFC population ratio from our
simulations relative to Duncan and Levison (1997), and then deduce from the
observations that the size-limited population ratio between the OC and the SD
is 44 (-34)(+54). From simulations we obtain 12 +- 1 but the agreement cannot
be rejected by the null hypothesis.
