This paper first reviews recent patterns of fertility and partnership in a number of European countries and Japan. Since the late 1960s, these countries have experienced significant fertility decline. Rather than by an increased incidence of childlessness, this was driven mainly by postponement of the first birth, and a limited number of births taking place thereafter. In addition, fewer marriages took place, while the incidence of cohabitation increased, marriage took place later, and marriages became more unstable, reflected in increasing divorce rates. Next, this paper reviews two commonly used explanatory frameworks of fertility decline - on increasing opportunity costs and on value change - and concludes that they cannot account for recent phenomena such as a reversed relation between female labour force participation and fertility, and between progressiveness and fertility, or persistently high desired fertility. This is because they fail to bring in the notion of combinability. The focus of the third section of this paper is on the policy implications of bringing in this notion of combinability.