http://www.simpletoremember.com/articles/a/WillYourGrandchildrenBeJews/
".. while 28% of children of intermarriage are being raised as Jews, only between 10% to 15% of this entire group ultimately marries Jews themselves. Thus, it is clear that nearly all the children of intermarriage are lost to the Jewish people."
"Just as the decision to intermarry is the product of countless previous decisions about how to live one’s life, so too the decision not to intermarry seems to be the product of a lifetime of Jewish living and learning. The research indicates that a stronger commitment to a higher level of Jewish education and observance leads to a lower likelihood of intermarriage and assimilation. The combination of Jewish commitment and having experienced a complete K-12 Orthodox Jewish Day School education results in an intermarriage rate of not greater than 3%. All the research indicates that it is essentially the Orthodox who are committed to such a complete Day School education."
"After all the trend lines have been drawn and graphs have been analyzed, population studies point to a single conclusion: Regardless of their own personal denominational affiliation, the most important choice that can be made by anyone who cares about the survival of the Jewish people is the choice to support increased religious observance and a full Orthodox Day School education for the maximum number of children".