Mind the gap: the compass of foregone fertility in Europe

“You can’t always get what you want” sang Mick Jagger in 1969. Four decades and a whole fertility transition later, European women wishing to form a family are well aware of the meaning of these lyrics. Over these four decades, desired family size has not changed much, with a predominant preference for two children, while actual family size has fallen considerably in most European countries. Indeed, if women’s desired family size was always fulfilled, then fertility would be much higher than current levels, and close to or above replacement. As shown by total fertility rates, today’s picture is quite different. Observed fertility is well below desired fertility, meaning that women seldom achieve their family size goals, and more worryingly, the persistence of such low fertility may be ‘downsizing’ childbearing intentions so that they more closely fit observed fertility, thus leading to a ‘low-fertility trap’ (Lutz et al. 2006) .How can this gap be quantified and broken down to understand its dynamics? How does it differ across European countries?