Volume 42 - Article 28 | Pages 777–798 Author has provided data and code for replicating results

Are sibling models a suitable tool in analyses of how reproductive factors affect child mortality?

By Øystein Kravdal

Print this page  Facebook  Twitter


Date received:24 Jan 2020
Date published:05 May 2020
Word count:4353
Keywords:bias, child mortality, reproductive factors, sibling models
Additional files:readme.42-28 (text file, 1022 Byte)
 42-28 additional material (pdf file, 28 kB)
 demographic-research.42-28 (zip file, 5 kB)


Background: Several studies of how reproductive factors affect child mortality or other child outcomes have been based on sibling comparisons. With such models one controls for unobserved determinants of the outcome that are shared by the siblings and linked to the reproductive process. However, it has been shown mathematically that estimates from sibling models are biased when the outcome for one sibling affects the exposure for another, and this is precisely the situation when the outcome is child mortality and the exposure is aspects of the mother’s reproductive behaviour. The goal of this analysis was to find out, by means of simulation, whether the bias really matters in practice.

Results: All simulation experiments showed that, when there was an effect of infant mortality on subsequent fertility, the estimated effect of higher maternal age was considerably more adverse than the true effect, while the effects of higher birth order and very short or very long birth interval were biased in the opposite direction.

Contribution: Although it is possible that the bias is unimportant in other situations than those examined here, a reasonable conclusion is that one should have serious doubts about sibling model estimates of effects of reproductive factors on infant or child mortality. Stated differently, we may know less about these effects than we tend to think and need other alternatives to a ‘naïve’ regression model than the sibling approach. Obviously, there may be problems also when analysing other child outcomes that affect subsequent fertility, through mortality or otherwise.

Author's Affiliation

Øystein Kravdal - Universitetet i Oslo, Norway [Email]

Other articles by the same author/authors in Demographic Research

» Taking birth year into account when analysing effects of maternal age on child health and other outcomes: The value of a multilevel-multiprocess model compared to a sibling model
Volume 40 - Article 43

» The increasing mortality advantage of the married: The role played by education
Volume 38 - Article 20

» What has high fertility got to do with the low birth weight problem in Africa?
Volume 28 - Article 25

» Further evidence of community education effects on fertility in sub-Saharan Africa
Volume 27 - Article 22

» Children's stunting in sub-Saharan Africa: Is there an externality effect of high fertility?
Volume 25 - Article 18

» Demographers’ interest in fertility trends and determinants in developed countries: Is it warranted?
Volume 22 - Article 22

» Does income inequality really influence individual mortality?: Results from a ‘fixed-effects analysis’ where constant unobserved municipality characteristics are controlled
Volume 18 - Article 7

» Effects of current education on second- and third-birth rates among Norwegian women and men born in 1964: Substantive interpretations and methodological issues
Volume 17 - Article 9

» Does cancer affect the divorce rate?
Volume 16 - Article 15

» A simulation-based assessment of the bias produced when using averages from small DHS clusters as contextual variables in multilevel models
Volume 15 - Article 1

» Educational differentials in male mortality in Russia and northern Europe: A comparison of an epidemiological cohort from Moscow and St. Petersburg with the male populations of Helsinki and Oslo
Volume 10 - Article 1

» The problematic estimation of "imitation effects" in multilevel models
Volume 9 - Article 2

» The impact of individual and aggregate unemployment on fertility in Norway
Volume 6 - Article 10

» Is the Previously Reported Increase in Second- and Higher-order Birth Rates in Norway and Sweden from the mid-1970s Real or a Result of Inadequate Estimation Methods?
Volume 6 - Article 9

» The High Fertility of College Educated Women in Norway: An Artefact of the Separate Modelling of Each Parity Transition
Volume 5 - Article 6

» A search for aggregate-level effects of education on fertility, using data from Zimbabwe
Volume 3 - Article 3

» An Illustration of the Problems Caused by Incomplete Education Histories in Fertility Analyses
Special Collection 3 - Article 6

Most recent similar articles in Demographic Research

» Slow-downs of fertility decline: When should we call it a 'fertility stall'?
Volume 46 - Article 26    | Keywords: child mortality

» Age patterns of under-5 mortality in sub-Saharan Africa during 1990‒2018: A comparison of estimates from demographic surveillance with full birth histories and the historic record
Volume 44 - Article 18    | Keywords: child mortality

» Child mortality levels and trends: A new compositional approach
Volume 43 - Article 43    | Keywords: child mortality

» Traditional versus Facebook-based surveys: Evaluation of biases in self-reported demographic and psychometric information
Volume 42 - Article 5    | Keywords: bias

» The effects of household and community context on mortality among children under five in Sierra Leone: Evidence from the 2013 Demographic and Health Survey
Volume 40 - Article 11    | Keywords: child mortality


»Volume 42





Similar Articles



Jump to Article

Volume Page
Volume Article ID