Short birth intervals become less common in Sweden: a decline of the speed-premium effect?
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Background: The so-called speed premium, introduced in Sweden in the 1980s and still in effect in 2018, grants some benefits regarding parental leave for parents that have two births within 2.5 years or shorter. Previous research has shown a great increase in the prevalence of short birth intervals in the 1980s and 1990s associated with the introduction of this policy.
Research question: This study investigates if short birth intervals (<2.5 years) are still common in recent years as they became in the 1980s–1990s.
Data and methods: An event history analysis of the risk of giving birth stratified by time since the previous birth is presented for the period 1970–2017. A piecewise exponential model is estimated with register data on the birth history of native-born women. Separate results are shown by parity.
Results: The spike in short birth intervals seen in the 1980s–1990s has mostly disappeared in recent years. By the 2010s, the pattern of birth intervals is similar to that seen around the time of the introduction of the speed premium in the early 1980s.
Main conclusions: The speed-premium might have contributed to a higher prevalence of short birth intervals during a certain period, but the present results suggest that its effect on birth spacing is relatively small in recent years.