There's evidence that the Palestinian population has been grossly exaggerated, as has its population growth:
The study, which has been accepted by prominent American demographers Dr. Nicholas Eberstadt and Murray Feshbach, shows that the Palestinian estimates overstate the Palestinian population west of the Jordan by about 50 percent. In addition, the Palestinian population growth projections are based on fertility rates that are inconsistent with data from the PA's own Ministry of Health. In short, the demographic bombshell appears to be a dud.
It is not surprising that the Palestinians would come up with false "we will bury you" type population estimates. The strange thing is that the Israelis accepted their enemies' data so readily. As Glick puts it, "like bats attracted to the darkness of a cave, we preferred the manipulative lies of the PA to the truth."
The shibboleth has been that given demographic trends, Israel cannot remain "democratic" and Jewish unless it sheds the occupied territories could be based upon bad data leading to erroneous conclusions.
What other demographic assumptions that lead to policy conclusion might also be wrong? Estimates of the number of illegal aliens in the U.S.? The Sunni-Shi'a-Kurdish balance in Iraq?
There's an awful lot of innumeracy and pseudoscience infecting public debate today. I need to post on Vioxx, for example.
One must emphasize that there may be other reasons to favor an end to the Israeli occupation, and supporting a two-state solution, that have nothing to do with demographics.