4. Results 6. Acknowledgements

5. Discussion

In this study we have considered the intensity of conception of a first shared child among couples where the current union is the second union for at least one partner. Half of these couples had a child in their second union, which is consistent with the level of childbearing following remarriage found by [Griffith et al. 1985] and [Kucera 1984]. Among those who had a child in their second union, six out of ten conceived the child within the first two years. And among this group, three out of ten conceptions occurred even before the couple moved into a joint household. For the majority of couples, the shared pregnancy came rather quickly.

We sum up our results by considering the value a first child may confer if pre-union children are present as opposed to the situation where the first shared child in the second union is the first child for both partners.

The rate at which a childless respondent has a first shared conception is independent of the partner's number of children, and it is not higher than for respondents who already have a pre-union child. We therefore conclude that our results do not support the presence of a parenthood effect. The explanation that a stepchild may substitute for a biological child and hence counteract the parenthood effect for childless partners does not seem to be valid either, for we could not find a significant interaction between the woman's and the man's pre-union children. However, the union commitment effect is present both for female and male respondents when they have fewer than two pre-union children, as it is if we restrict the hypothesis to pre-union children not living in the household at the time of the formation of the second union (compare Model 4, Table 3). These results are in agreement with the findings of [Kucera 1984] but in contrast to those of [Vikat et al. 1999] and [Griffith et al. 1985], where the union commitment effect is independent of the number of pre-union children. These differing results could stem from differences in information about the partner's pre-union children contained in these studies. In the study by [Vikat et al. 1999] information on the partner's pre-union children is restricted to responses to the question `Did the partner have any children who joined the current union?' By contrast , our study allows us to control for the exact number of pre-union children from either partner.

An unambiguous result of our study is the difference in the effect of pre-union children between those that join the newly formed household and those that do not. Our results clearly indicate that the rate at which a first child is conceived in a second union is influenced predominantly by pre-union children who live in the household at the time of union formation. These findings are also different from those of [Vikat et al. 1999]'s for Sweden, where almost no differences in the rate of a first child were found regarding resident vs. non resident pre-union children. In interpreting these conclusions we again have to keep in mind the exceptionally good quality of the Austrian data with regard to information on the partner's pre-union children. Moreover, our findings of a fertility-reducing impact if there are at least two pre-union children living in the household corresponds to the results reported in [Kucera 1984] and [Toulemon 1997].

The Swedish study [Vikat et al. 1999] has shown that a man's parity counts as much as the female partner's parity in determining a couple's shared parity. This is also the case for Austria, but in the Austrian data the man's parity counts even more if he has a pre-union child living in the household (Model 4 in Table 3). This result is in accordance with the findings in [Toulemon 1997], who found that the risk of having a first shared birth increases if the man had a pre-union child living in the household. But as we have shown in Figure 1, the higher intensity of the conception of a first common child for couples where the man brings a child into the household only holds when the woman has no pre-union child living in the household at the time of formation of the second union. These results demonstrate that a first common child is conceived at a rate which not only depends on the man's and the woman's parity separately but also on the combination of the two. Even more specifically, the elevated intensity of the conception of a first common child for such couples will only hold during the first nine months after the start of the second union (compare Figure 1). This could indicate that the woman strongly wants to have a common biological child very quickly after the start of the union.

To control not only for the woman's and the man's parity but also for the age of the youngest child at the start of the union, we have had to restrict our analysis to female respondents only. The results (Table 5 and Figure 2) show that the age of the youngest child at the start of the union has an important influence on the rate at which a first common child is conceived in the second union. Not only do we observe higher first conception intensities if the youngest child is under the age of five at the start of the second union, our results also indicate that the intensity of conception may increase with the duration of the second union for those couples.

Though we could not find any significant effect of the sex of the respondent in models where we combined both sexes, running separate models for male and female respondents highlights an important difference: Female respondents in their second union may be different from female partners in unions that are the second ones for male respondents. Of all pre-union children only those from the male partner living in the household have an effect on the rate of conception of the first shared child. Though no firm conclusions can be drawn, these results suggest that it is important to consider not only whose pre-union children are living in the common household but it seems to be equally important to control better for whose second union we are actually considering. Further effort has to be put into complementing childbearing histories of both partners with partnership histories of both partners. Only when such data are available can we better judge how robust the effects of pre-union children will be across various combinations of partnership histories.


4. Results 6. Acknowledgements

Fertility in second unions in Austria: Findings from the Austrian FFS
Isabella Buber, Alexia Prskawetz
© 2000 Max-Planck-Gesellschaft ISSN 1435-9871