Discussion Acknowledgements
5 Conclusion
This study provides strong evidence that among people aged 50 and older, those born in winter have a higher life expectancy than those born in summer. This pattern appears not to be the result of factors that shorten one’s life span at the end of life. It seems rather to result from factors that affect individuals early in life. I have raised three hypotheses to explain the relationship between month of birth and longevity. I finally came to the conclusion that at present it is not yet known whether the underlying causal mechanisms are of a social or of a biological nature. However, I found evidence that in Denmark selective survival during the first year of life cannot explain the observed phenomenon. More insights into the causal mechanisms will be gained by undertaking comparative studies of populations born in the northern and the southern hemispheres. In addition, the analysis of seasonal patterns in infant mortality and stillbirths may shed more light on the relationship between month of birth and life expectancy at older ages.
Discussion Acknowledgements

logo70.gif (2450 bytes)

Longevity and Month of Birth:
Evidence from Austria and Denmark

Gabrielle Doblhammer
1999 - 2000 Max-Planck-Gesellschaft ISSN 1435-9871