BREAKING DOWN 'Normative Economics'. Normative statements are often heard in the media because they tend to represent a theory or opinion rather than objective analysis. Normative economics is a valuable way to establish goals and generate new ideas, but it should not be used as a basis for policy decisions.
You may find yourself wondering if your baby can sleep on his stomach, especially if he appears to be more comfortable that way. To prevent Sudden Infant Death Syndrome, or SIDS, which remains a threat until your baby is 12 months of age, it is best for her to sleep on her back, instead of her stomach.
Ferber states by 3-4 months most six month old babies should be able to sleep through the night. He doesn't say how long sleeping through the night is (at least I couldn't find it) but my guess is that he's going by 5 hours.