In the face of below replacement and still declining national fertility rates in most Western societies, the proportion of reproductively aged women having a third or higher order birth has particular demographic signi cance. This paper seeks to complement previous survey-based studies of the socio-economic, behavioural and motivational characteristics of individuals progressing or intending to progress from a second to a third or higher order birth by examining the spatial patterning and ecological context of such births in NSW during 1996 and, in particular, the extent to which such births are especially characteristic of socially disadvantaged regions and localities in the state. The results suggest that while there is a clear, though not overwhelming, tendency towards such a concentration there is an equally clear tendency for older women living in some of the most socially advantaged areas of the metropolitan zone to engage in higher order childbearing, thereby suggesting the operation of multiple causal pathways. In the more disadvantaged areas of the metropolitan zone religious and/or ethnically based pro-natalist value sets also appear to play a signi cant role. In better-off localities, however, higher order reproduction would seem to re ect the greater choices -and resources -available to women, whether in or out of the labour force. Because ecological analysis cannot provide precise answers to behavioural questions and because only higher order births to women in current relationships have been taken into account in this study, further research, employing a variety of methodologies, operating at a variety of scales and drawing on alternative data sets would seem desirable if such questions are to be more fully elucidated and their policy implications better understood.Not surprisingly, documenting and elucidating the phenomenon of who has a third or higher order child has attracted more than a little interest, both internationally (e.g.
