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Fertility rates in most developed societies have been declining at younger ages and rising at older ages. This phenomenon is widely referred to as reflecting the postponement of fertility. But is this an accurate description? The present paper considers whether recent changes in the age-pattern of childbearing in France can be described as postponement. The statistical features of time series of rates are distinguished from the underlying behavioural process generating them. Criteria for the presence of postponement are proposed. In the absence of detailed, longitudinal information on intentions, the occurrence or otherwise of postponement is assessed by indirect means. Some evidence is found consistent with fertility postponement in recent decades. However, it cannot be interpreted causally, and so cannot be used either to explain recent trends or to anticipate future trends. Much more detailed evidence is required to establish the existence of postponement in the behavioural sense than is generally assumed.

Short-term variations in fertility and seasonal patterns of childbearing have been of interest to demographers for a long time. Presenting our detailed study of period fertility in Austria since 1984, we discuss the problems and advantages of constructing and analysing monthly series of various period fertility indicators that reflect real exposure and potentially minimise the distortions caused by changes in fertility timing. We correct monthly birth data for calendar and seasonal factors and show that seasonality of births in Austria varies by birth order. Our study suggests that most of the timing distortions can be eliminated when using an indicator derived from the period parity progression ratios based on birth interval distributions, termed the “period average parity” (PAP). We illustrate the insights gained with the PAP and compare this with the commonly used total fertility rates in an analysis of the recent upswing in period fertility, starting in the late 2001. This investigation will be useful in establishing a monitoring of monthly fertility rates in Austria.