On the Optimality of the LR Test for Mediation

Testing for mediation, or indirect effects, is empirically very important in many disciplines. It has two obvious symmetries that the testing procedure should be invariant to. The ordered absolute t-statistics from two ordinary regressions are maximal invariant under the associated groups of transfo...

Full description

Bibliographic Details
Main Authors: Kees Jan Van Garderen, Noud Van Giersbergen
Format: Article
Language:English
Published: MDPI AG 2022-01-01
Series:Symmetry
Subjects:
Online Access:https://www.mdpi.com/2073-8994/14/1/178
_version_ 1797490031751856128
author Kees Jan Van Garderen
Noud Van Giersbergen
author_facet Kees Jan Van Garderen
Noud Van Giersbergen
author_sort Kees Jan Van Garderen
collection DOAJ
description Testing for mediation, or indirect effects, is empirically very important in many disciplines. It has two obvious symmetries that the testing procedure should be invariant to. The ordered absolute t-statistics from two ordinary regressions are maximal invariant under the associated groups of transformations. Sobel’s (1982) Wald-type and the LR test statistic are both functions of this maximal invariant and satisfy two logical coherence requirements: (1) size coherence: rejection at level <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> implies rejection at all higher significance levels; and (2) information coherence: more (less) evidence against the null implies continued (non) rejection of the null. The LR test statistic is simply the smallest of the two absolute t-statistics, and we show that the LR test is the Uniformly Most Powerful (information and size) Coherent Invariant (UMPCI) test. In short: the LR test for mediation is simple and best.
first_indexed 2024-03-10T00:26:09Z
format Article
id doaj.art-e330b714f4e84327bae76a5f842a4055
institution Directory Open Access Journal
issn 2073-8994
language English
last_indexed 2024-03-10T00:26:09Z
publishDate 2022-01-01
publisher MDPI AG
record_format Article
series Symmetry
spelling doaj.art-e330b714f4e84327bae76a5f842a40552023-11-23T15:34:39ZengMDPI AGSymmetry2073-89942022-01-0114117810.3390/sym14010178On the Optimality of the LR Test for MediationKees Jan Van Garderen0Noud Van Giersbergen1UvA Econometrics, Amsterdam School of Economics, University of Amsterdam, Roetersstraat 11, 1018 WB Amsterdam, The NetherlandsUvA Econometrics, Amsterdam School of Economics, University of Amsterdam, Roetersstraat 11, 1018 WB Amsterdam, The NetherlandsTesting for mediation, or indirect effects, is empirically very important in many disciplines. It has two obvious symmetries that the testing procedure should be invariant to. The ordered absolute t-statistics from two ordinary regressions are maximal invariant under the associated groups of transformations. Sobel’s (1982) Wald-type and the LR test statistic are both functions of this maximal invariant and satisfy two logical coherence requirements: (1) size coherence: rejection at level <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> implies rejection at all higher significance levels; and (2) information coherence: more (less) evidence against the null implies continued (non) rejection of the null. The LR test statistic is simply the smallest of the two absolute t-statistics, and we show that the LR test is the Uniformly Most Powerful (information and size) Coherent Invariant (UMPCI) test. In short: the LR test for mediation is simple and best.https://www.mdpi.com/2073-8994/14/1/178coherenceindirect effectmaximal invariantSobelstatistics
spellingShingle Kees Jan Van Garderen
Noud Van Giersbergen
On the Optimality of the LR Test for Mediation
Symmetry
coherence
indirect effect
maximal invariant
Sobel
statistics
title On the Optimality of the LR Test for Mediation
title_full On the Optimality of the LR Test for Mediation
title_fullStr On the Optimality of the LR Test for Mediation
title_full_unstemmed On the Optimality of the LR Test for Mediation
title_short On the Optimality of the LR Test for Mediation
title_sort on the optimality of the lr test for mediation
topic coherence
indirect effect
maximal invariant
Sobel
statistics
url https://www.mdpi.com/2073-8994/14/1/178
work_keys_str_mv AT keesjanvangarderen ontheoptimalityofthelrtestformediation
AT noudvangiersbergen ontheoptimalityofthelrtestformediation