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− | ==Causal mediation analysis== | + | ==References== |
− | ===Fixing versus conditioning=== | + | {{Dual|source=Causal Analysis in Theory and Practice|sourcepath=http://www.mii.ucla.edu/causality/?p=713|date=19 June 2014}}{{Dead link|date=February 2020}} |
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− | Mediation analysis quantifies the extent to which a variable participates in the transmittance of change from a cause to its effect. It is inherently a causal
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− | notion, hence it cannot be defined in statistical terms. Traditionally,
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− | however, the bulk of mediation analysis has been conducted
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− | within the confines of linear regression, with statistical
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− | terminology masking the causal character of the
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− | relationships involved. This led to difficulties,
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− | biases, and limitations that have been alleviated by
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− | modern methods of causal analysis, based on causal diagrams
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| + | ;Notes |
| + | {{reflist|30em}} |
| + | ;Bibliography |
| + | *{{Cite journal |
| + | | last = Preacher |
| + | | first = Kristopher J. |
| + | | last2 = Hayes |
| + | | first2 = Andrew F. |
| + | | title = SPSS and SAS procedures for estimating indirect effects in simple mediation models |
| + | | journal = Behavior Research Methods, Instruments, and Computers |
| + | | volume = 36 |
| + | | issue = 4 |
| + | | pages = 717–731 |
| + | | url = http://www.afhayes.com/spss-sas-and-mplus-macros-and-code.html |
| + | | year = 2004 |
| + | | doi = 10.3758/BF03206553 |
| + | | pmid = 15641418 |
| + | | doi-access = free |
| + | }} |
| + | *{{Cite journal |
| + | | last = Preacher |
| + | | first = Kristopher J. |
| + | | last2 = Hayes |
| + | | first2 = Andrew F. |
| + | | title = Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models |
| + | | journal = Behavior Research Methods |
| + | | volume = 40 |
| + | | issue = 3 |
| + | | pages = 879–891 |
| + | | url = http://www.afhayes.com/spss-sas-and-mplus-macros-and-code.html |
| + | | year = 2008 |
| | doi = 10.3758/BRM.40.3.879 | | | doi = 10.3758/BRM.40.3.879 |
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− | | doi = 10.3758/BRM. 40.3.879
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− | and counterfactual logic.
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| | pmid = 18697684 | | | pmid = 18697684 |
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− | 18697684
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| | doi-access = free | | | doi-access = free |
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− | 免费访问
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− | The source of these difficulties lies in defining mediation
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− | }}
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| }} | | }} |
− | | + | *{{Cite journal |
− | in terms of changes induced by adding a third variables into
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− | a regression equation. Such statistical changes are
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| | last = Preacher | | | last = Preacher |
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− | | last = Preacher
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− | epiphenomena which sometimes accompany mediation but,
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| | first = K. J. | | | first = K. J. |
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− | | 第一 = k. j。
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− | in general, fail to capture the causal relationships that
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| | last2 = Zyphur | | | last2 = Zyphur |
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− | 2 = Zyphur
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− | mediation analysis aims to quantify.
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| | first2 = M. J. | | | first2 = M. J. |
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− | 2 = m. j.
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| | last3 = Zhang | | | last3 = Zhang |
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− | 3 = Zhang
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− | The basic premise of the causal approach is that it is
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| | first3 = Z. | | | first3 = Z. |
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− | 3 = z.
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− | not always appropriate to "control" for the mediator ''M''
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| | title = A general multilevel SEM framework for assessing multilevel mediation | | | title = A general multilevel SEM framework for assessing multilevel mediation |
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− | | title = 用于评估多层次调解的通用多层次结构方程模型框架
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− | when we seek to estimate the direct effect of ''X'' on ''Y''
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| | journal = Psychological Methods | | | journal = Psychological Methods |
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− | 心理学方法
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− | (see the Figure above).
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| | volume = 15 | | | volume = 15 |
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− | 15
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− | The classical rationale for "controlling" for ''M''"
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| | issue = 3 | | | issue = 3 |
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− | 第三期
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− | is that, if we succeed in preventing ''M'' from changing, then
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| | pages = 209–233 | | | pages = 209–233 |
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− | | pages = 209-233
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− | whatever changes we measure in Y are attributable solely
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| | year = 2010 | | | year = 2010 |
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− | 2010年
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− | to variations in ''X'' and we are justified then in proclaiming the
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| | doi = 10.1037/a0020141 | | | doi = 10.1037/a0020141 |
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− | | doi = 10.1037/a0020141
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− | effect observed as "direct effect of ''X'' on ''Y''." Unfortunately,
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| | pmid = 20822249 | | | pmid = 20822249 |
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− | 20822249
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− | "controlling for ''M''" does not physically prevent ''M'' from changing;
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| | citeseerx = 10.1.1.570.7747 | | | citeseerx = 10.1.1.570.7747 |
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− | 10.1.1.570.7747
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− | it merely narrows the analyst's attention to cases
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− | }}
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| }} | | }} |
| + | * Baron, R. M. and Kenny, D. A. (1986) "The Moderator-Mediator Variable Distinction in Social Psychological Research – Conceptual, Strategic, and Statistical Considerations", [[Journal of Personality and Social Psychology]], Vol. 51(6), pp. 1173–1182. |
| + | *Cohen, J. (1988). ''Statistical power analysis for the behavioral sciences'' (2nd ed.). New York, NY: Academic Press. |
| + | * {{cite journal | last1 = Hayes | first1 = A. F. | year = 2009 | title = Beyond Baron and Kenny: Statistical mediation analysis in the new millennium | journal = Communication Monographs | volume = 76 | issue = 4| pages = 408–420 | doi = 10.1080/03637750903310360 }} |
| + | *Howell, D. C. (2009). ''Statistical methods for psychology'' (7th ed.). Belmot, CA: Cengage Learning. |
| + | *{{cite journal | last1 = MacKinnon | first1 = D. P. | last2 = Lockwood | first2 = C. M. | year = 2003 | title = Advances in statistical methods for substance abuse prevention research | journal = Prevention Science | volume = 4 | issue = 3| pages = 155–171 | doi = 10.1023/A:1024649822872 | pmid = 12940467 | pmc = 2843515 }} |
| + | *{{cite journal | last1 = Preacher | first1 = K. J. | last2 = Kelley | first2 = K. | year = 2011 | title = Effect sizes measures for mediation models: Quantitative strategies for communicating indirect effects | journal = Psychological Methods | volume = 16 | issue = 2| pages = 93–115 | doi = 10.1037/a0022658 | pmid = 21500915 }} |
| + | *Rucker, D.D., Preacher, K.J., Tormala, Z.L. & Petty, R.E. (2011). "Mediation analysis in social psychology: Current practices and new recommendations". ''Social and Personality Psychology Compass'', 5/6, 359–371. |
| + | *{{cite journal | last1 = Sobel | first1 = M. E. | year = 1982 | title = Asymptotic confidence intervals for indirect effects in structural equation models | journal = Sociological Methodology | volume = 13 | pages = 290–312 | doi = 10.2307/270723 | jstor = 270723 }} |
| + | *{{cite journal | last1 = Spencer | first1 = S. J. | last2 = Zanna | first2 = M. P. | last3 = Fong | first3 = G. T. | year = 2005 | title = Establishing a causal chain: why experiments are often more effective than mediational analyses in examining psychological processes | journal = Journal of Personality and Social Psychology| volume = 89 | issue = 6| pages = 845–851 | doi=10.1037/0022-3514.89.6.845 | pmid=16393019}} |
| + | *{{cite book|last1=Pearl|first1=Judea|editor1-last=Berzuini|editor1-first=C.|editor2-last=Dawid|editor2-first=P.|editor3-last=Bernardinelli|editor3-first=L.|title=Causality: Statistical Perspectives and Applications|date=2012|publisher=John Wiley and Sons, Ltd.|location=Chichester, UK|pages=151–179|chapter=The Mediation Formula: A guide to the assessment of causal pathways in nonlinear models}} |
| + | *Shaughnessy J.J., Zechmeister E. & Zechmeister J. (2006). ''Research Methods in Psychology'' (7th ed., pp. 51–52). New York: McGraw Hill. |
| + | *{{cite journal | last1 = Tolman | first1 = E. C. | year = 1938 | title = The Determiners of Behavior at a Choice Point | journal = Psychological Review | volume = 45 | pages = 1–41 | doi=10.1037/h0062733}} |
| + | *{{cite journal | last1 = Tolman | first1 = E. C. | last2 = Honzik | first2 = C. H. | year = 1930 | title = Degrees of hunger, reward and nonreward, and maze learning in rats | journal = University of California Publications in Psychology | volume = 4 | pages = 241–275 }} |
| + | *{{cite book| last1 = Vanderweele| first1 = Tyler J. | year = 2015| title = Explanation in Causal Inference }} |
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− | of equal ''M'' values. Moreover, the language of probability
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− | theory does not possess the notation to express the idea
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− | of "preventing ''M'' from changing" or "physically holding ''M'' constant".
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− | The only operator probability provides is "Conditioning"
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− | which is what we do when we "control" for ''M'',
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− | or add ''M'' as a regressor in the equation for ''Y''.
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− | The result is that, instead of physically holding ''M" constant
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− | (say at ''M'' = ''m'') and comparing ''Y'' for units under ''X'' = 1' to those under
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− | ''X'' = 0, we allow ''M'' to vary but ignore all units except those in
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− | which ''M'' achieves the value ''M'' = ''m''. These two operations are
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− | fundamentally different, and yield different results,<ref>{{cite journal|last1=Robins|first1=J.M.|last2=Greenland|first2=S.|title=Identifiability and exchangeability for direct and indirect effects|journal=Epidemiology|date=1992|volume=3|issue=2|pages=143–155|doi=10.1097/00001648-199203000-00013|pmid=1576220}}</ref><ref name="pearl1994" >{{cite journal|last1=Pearl|first1=Judea|editor1-last=Lopez de Mantaras|editor1-first=R.|editor2-last=Poole|editor2-first=D.|title=A probabilistic calculus of actions|journal=Uncertainty in Artificial Intelligence 10|volume=1302|date=1994|pages=454–462|publisher=[[Morgan Kaufmann]]|location=San Mateo, CA|bibcode=2013arXiv1302.6835P|arxiv=1302.6835}}</ref> except in the case of no omitted variables.
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− | To illustrate, assume that the error terms of ''M'' and ''Y''
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− | are correlated. Under such conditions, the
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− | structural coefficient ''B'' and ''A'' (between ''M'' and ''Y'' and between ''Y'' and ''X'')
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− | can no longer be estimated by regressing ''Y'' on ''X'' and ''M''.
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− | In fact, the regression slopes may both be nonzero
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− | even when ''C'' is zero.<ref>{{cite journal|pmid=24885338|year=2014|last1=Pearl|first1=J|title=Interpretation and identification of causal mediation|journal=Psychological Methods|volume=19|issue=4|pages=459–81|doi=10.1037/a0036434|url=ftp://ftp.cs.ucla.edu/pub/stat_ser/r389-imai-etal-commentary-r421-reprint.pdf}}</ref> This has two
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− | consequences. First, new strategies must be devised for
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− | estimating the structural coefficients ''A,B'' and ''C''. Second,
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− | the basic definitions of direct and indirect effects
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− | must go beyond regression analysis, and should
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− | invoke an operation that mimics "fixing ''M''",
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− | rather than "conditioning on ''M''."
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| Category:Statistical models | | Category:Statistical models |
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| 类别: 独立概率论 | | 类别: 独立概率论 |
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− | ===Definitions===
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| Category:Psychometrics | | Category:Psychometrics |