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Same-sex marriage -- Netherlands, Same-sex marriage -- Law and legislation -- Netherlands, Gay couples -- Legal status -- Netherlands


In the recent Demography article titled “The Effect of Same-Sex Marriage Laws on Different-Sex Marriage: Evidence From the Netherlands,” Trandafir attempted to answer the question, Are rates of opposite sex marriage affected by legal recognition of same sex marriages? The results of his approach to statistical inference—looking for evidence of a difference in rates of opposite-sex marriage—provide an absence of evidence of such effects. However, the validity of his conclusion of no causal relationship between same-sex marriage laws and rates of opposite-sex marriage is threatened by the fact that Trandafir did not also look for equivalence in rates of opposite-sex marriage in order to provide evidence of an absence of such an effect. Equivalence tests in combination with difference tests are introduced and presented in this article as a more valid inferential approach to the substantive question Trandafir attempted to answer.


This is the author’s version of a work that was accepted for publication in Demography. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. The final publication is available at Springer via

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