Most theoretical attention in relation to sex preferences for children has focused on son preferences. Much theory has focused on how gender roles and their interaction with kinship systems determine unequal abilities for sons and daughters to contribute to the household over the life course (Das Gupta et al. 2003). In many historical settings and in contemporary societies in South and East Asia, sons tend to be perceived as the key source of contribution to the household in the form of paid labor or work in the family farm (e.g., Sandström and Vikström 2015). The contributions of daughters tend to center in providing unpaid domestic work and care to younger and older family members. A higher demand for boys over girls may emerge from the dependency among many families on the economic contribution brought by sons, especially in contexts of lower incomes and restricted social security. This gendered division of labor may be compounded by social norms that regulate kinship systems, especially when these systems are patrilineal and residence is patrilocal. In these cases, daughters may be expected to provide care to their husband’s family after marriage rather than to their own parents. In some contexts, parents might be expected to pay dowries for daughters, and inheritance laws may disproportionally favor male offspring (Basu and Das Gupta 2001).

Since son preferences have been attributed to unequal gender roles in patriarchal societies, it could be expected that sex preference for children would be virtually non-existent in societies with greater gender equality. The empirical evidence on sex preferences and childbearing reviewed above does not fully support this narrative, however, for two main reasons. First, in many societies that have less rigid gender roles and in which there is no clear son preference, a preference for a child of each sex is still evident. This is, for example, the case in the United States (Pollard and Morgan 2002), Australia (Kippen et al. 2007) and much of Europe, including Sweden (Hank and Kohler 2000; Andersson et al. 2006). This indicates that in those societies, sons and daughters are not viewed as equivalent values to parents (e.g., Hoffman and Hoffman 1973).

A second empirical finding that problematizes the hypothesis that sex preferences for children would be unimportant in societies with greater gender equality comes from recent analyses of changes in sex preferences over time. While most studies of sex preferences are based on cross-sectional comparisons of countries, mostly due to data limitations, a few studies have been able to produce long and consistent time series for the same country. Some examples are the studies of the Nordic countries by Andersson et al. (2006, 2007), discussed above. In international comparisons, those countries are often placed among those with the highest level of gender equality, and continued progress in that area has been made over the last decades (World Economic Forum 2016; Frejka et al. 2017). Therefore, one may expect that parents in those societies would become more neutral over time to sex preferences and that birth rates would become gradually more independent of the sex composition of previous offspring. However, the analysis of third birth risks by Andersson and colleagues suggested otherwise: having at least one daughter seems more important to parents in contemporary Denmark, Norway, and Sweden than having at least one son. More significantly, this pattern emerged around the 1980s and had not shown any sign of decline until the late 1990s, the last data point available in the literature. In short, the developments in those Nordic countries point to the opposite direction that would be expected by a straightforward association between gender equality and the decline of sex preferences, as entirely new patterns of differential birth rates have emerged in the recent past.

The theory of a two-stage gender revolution, as put forward by Goldscheider et al. (2015), can help organize the discussion around this apparent contradiction between gender equality and persistent preferences for the sex composition of offspring. The theory suggests that recent gains in gender equality and the decline of the male breadwinner family model in developed societies can be analytically divided into two phases, referring to changes in the public and private sphere, respectively. Changes in the public sphere relate to increases in female participation in the previously male-dominated market of paid labor. The second phase relates to increasing equality in the division of labor in the private sphere, by which men participate more actively in unpaid domestic work, such as childrearing. The two stages of the gender revolution tend to follow each other in a temporal manner, but a temporal gap between the two stages may create a “second shift” for women (Goldscheider et al. 2015). This concept refers to the situation when women accumulate the double burden of contributing to paid work and being responsible for household work while the second part of the gender revolution is not complete.

Given the multiple dimensions of gender equality, it is difficult to assess how far the second part of the gender revolution has advanced in Sweden. On the one hand, Swedish men hold an increasing share of domestic tasks. Public policies promote gender equality in the use of parental leave and fathers’ uptake has increased in recent years (Duvander and Johansson 2012; Statistics Sweden 2016). On the other hand, men and women tend to specialize in different types of housework (Kan et al. 2011) and the vast majority of parental leave days continues to be used by mothers (Statistics Sweden 2016). Available statistics on care for elderly parents provide yet additional evidence of the difficult convergence of gender roles in the private sphere. Institutional care and home help services to the elderly were cut back substantially during the 1980s and 1990s and female relatives took most of the extra share of required care. By 2000, daughters in Sweden were two and a half times more likely than sons to be the care provider to an elderly parent who lived alone and had needs (Johansson et al. 2003).

In our study, we use the framework of the two-stage gender revolution to help explain sex preferences for children and the recent developments in birth rate differentials in Sweden. Applied to the study of preferences for the sex of children, a slow progress in the second part of the gender revolution means that parents continue to see sons and daughters as having some inherently different traits and strengths, even if gender roles are apparently more flexible. With the increase in female labor force participation, parents may expect that both sons and daughters can provide financial help at old age, or at least support themselves and their own families, but that daughters might continue to be seen as a more reliable source of care and social support. This narrative is compatible with the desire in Sweden to have at least one daughter.