Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

The casual effect of fertility : Reviewing the multiple problems with instrumental variables for the number of children in families

Öberg, Stefan LU orcid (2021)
Abstract
Studies investigating how the number of children in a family affects the parents or the children face problems because the variable of interestis endogenous in the model. The currently accepted solution to this problem is to use instrumental variables (IVs), for example, based on twin births. In this paper, I review and add to the critique of IVs based on twin births and show that that there are so many issues—major and minor—with these IVs that results based on them are not reliable or interpretable. I also review other IVs used in the literature, for example IVs based on the sexes of the firstborn children, and conclude that there are, as of yet, no credible IVs for the number of children. We need to disregardresults from studies ... (More)
Studies investigating how the number of children in a family affects the parents or the children face problems because the variable of interestis endogenous in the model. The currently accepted solution to this problem is to use instrumental variables (IVs), for example, based on twin births. In this paper, I review and add to the critique of IVs based on twin births and show that that there are so many issues—major and minor—with these IVs that results based on them are not reliable or interpretable. I also review other IVs used in the literature, for example IVs based on the sexes of the firstborn children, and conclude that there are, as of yet, no credible IVs for the number of children. We need to disregardresults from studies applying these IVs, reevaluate the current state of knowledge, and develop new, more credible methods. (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Working paper/Preprint
publication status
published
subject
publisher
SocArXiv Papers
DOI
10.31235/osf.io/peuvz
language
English
LU publication?
no
id
689f5783-670e-40ae-9de3-5daca9b761b6
date added to LUP
2025-09-15 13:46:05
date last changed
2025-10-17 11:07:35
@misc{689f5783-670e-40ae-9de3-5daca9b761b6,
  abstract     = {{Studies investigating how the number of children in a family affects the parents or the children face problems because the variable of interestis endogenous in the model. The currently accepted solution to this problem is to use instrumental variables (IVs), for example, based on twin births.  In this paper, I review and add to the critique of IVs based on twin births and show that that there are so many issues—major and minor—with these IVs that results based on them are not reliable or interpretable. I also review other IVs used in the literature, for example IVs based on the sexes of the firstborn children, and conclude that there are, as of yet, no credible IVs for the number of children. We need to disregardresults   from   studies   applying   these   IVs,   reevaluate   the   current   state   of knowledge, and develop new, more credible methods.}},
  author       = {{Öberg, Stefan}},
  language     = {{eng}},
  month        = {{09}},
  note         = {{Preprint}},
  publisher    = {{SocArXiv Papers}},
  title        = {{The casual effect of fertility : Reviewing the multiple problems with instrumental variables for the number of children in families}},
  url          = {{http://dx.doi.org/10.31235/osf.io/peuvz}},
  doi          = {{10.31235/osf.io/peuvz}},
  year         = {{2021}},
}