<div dir="ltr">Alina,<div><br></div><div> For the examples of sensitivity analyses, you should look at our APSR paper. Our psychological methods paper also has some examples too. For the post-treatment variable issue, here is the paper you can look at: <a href="http://imai.princeton.edu/research/medsens.html">http://imai.princeton.edu/research/medsens.html</a> The procedure is implemented in the R package too: <a href="http://imai.princeton.edu/research/files/mediationR2.pdf">http://imai.princeton.edu/research/files/mediationR2.pdf</a></div>
<div><br></div><div>Best,</div><div>Kosuke</div></div><div class="gmail_extra"><br clear="all"><div><div dir="ltr"><div>Kosuke Imai</div><div>Department of Politics<br></div><div>Princeton University</div><div><a href="http://imai.princeton.edu" target="_blank">http://imai.princeton.edu</a></div>
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<br><br><div class="gmail_quote">On Fri, Aug 15, 2014 at 9:51 AM, Feinholdt, A. <span dir="ltr"><<a href="mailto:A.Feinholdt@uva.nl" target="_blank">A.Feinholdt@uva.nl</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div style="direction:ltr;font-family:Tahoma;color:#000000;font-size:10pt">Dear Kosuke,
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<div>a couple of days ago, I was in contact with you concerning a STATA code for the sensitivity analysis. Fortunately, I was able to understand and run the R code. However, I am currently facing two problems: Since your analysis is still new, there are only
a handful of studies which use the sensitivity analysis to strengthen their results. However, from these studies it is unclear what and how to report findings from the sensitivity analysis. <span style="font-size:10pt">Therefore, I would like to seek your
advice on this matter. That is, what do you think is essential to be reported from a sensitivity analysis? </span></div>
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<div>The other problem concerns my findings: The goal of my study (an experimental online survey in which participants were randomly assigned to one of four conditions) was to show that framing effects would be serially mediated through two emotions. To support
the validity of a serial mediation, I have first run a "normal" causal mediation analysis with R while ignoring the possibility of a potential post-treatment confounder. Here the findings supported the notion of an ACME through one of the two emotions. Next,
I have tested the causal mediation analysis with confounding by an alternative pathway. This analysis demonstrated that ACME was no longer significant - neither in the treatment nor in the control group. As such, I have concluded that the initial assumption
was no longer tenable once the post-treatment confounder was accounted for. In addition, I have argued that under conditions like these it would be important to refer to other analytical strategies such as the serial mediation analysis - since this one does
not presupposes causal independence between pathways. </div>
<div>I can assume that this description is pretty vague but it may be enough for you to conclude, whether the sensitivity analysis can be used to support the application of a serial mediation analysis or not?</div>
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<div>I can imagine that you have a busy schedule but maybe you can find some time to consult me on the aforementioned issues.</div>
<div>Thanks in advance for reading my e-mail and I hope to hear from you.</div>
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<div><span style="font-size:10pt">Best wishes,</span></div>
<div><span style="font-size:10pt">Alina Feinholdt</span></div>
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<div><i>PhD candidate</i></div>
<div><i>Amsterdam School of Communication Research</i></div>
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<div style="direction:ltr"><font face="Tahoma" color="#000000"><b>Von:</b> Kosuke Imai [<a href="mailto:kimai@princeton.edu" target="_blank">kimai@princeton.edu</a>]<br>
<b>Gesendet:</b> Mittwoch, 6. August 2014 11:34<br>
<b>An:</b> Feinholdt, A.<br>
<b>Betreff:</b> Re: STATA - sensitivity analysis<br>
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<div dir="ltr">Dear Alina,
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<div> Unfortunately, we don't have this code in STATA. But, you can use our R package, which is pretty straightforward even if you don't know much about R. Try this tutorial, which gives you a step-by-step instruction: <a href="http://imai.princeton.edu/research/files/mediationR2.pdf" target="_blank">http://imai.princeton.edu/research/files/mediationR2.pdf</a></div>
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<div>Best,</div>
<div>Kosuke</div>
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<div>---------------------------------------------------------<br>
Kosuke Imai Office: Corwin Hall 036<br>
Professor Phone: <a href="tel:609-258-6601" value="+16092586601" target="_blank">609-258-6601</a><br>
Department of Politics Fax: <a href="tel:609-258-1110" value="+16092581110" target="_blank">609-258-1110</a><br>
Princeton University Email: kimai@Princeton.Edu<br>
Princeton, NJ 08544-1012 <a href="http://imai.princeton.edu" target="_blank">http://imai.princeton.edu</a><br>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Wed, Aug 6, 2014 at 3:52 AM, Feinholdt, A. <span dir="ltr">
<<a href="mailto:A.Feinholdt@uva.nl" target="_blank">A.Feinholdt@uva.nl</a>></span> wrote:<br>
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Dear prof. Imai,
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<div>my name is Alina Feinholdt and I am a PhD student at the University of Amsterdam, the Netherlands. I just recently read one of your papers on "Identification and Sensitivity Analysis for Multiple Causal Mechanisms: Revisiting Evidence from Framing Experiment".
Since I am dealing myself with potential post-treatment confounders (two emotions are studied as pathways following news framing), I would like to run both the mediation effect analysis and the sensitivity analysis with STATA. However, so far I could only
find an R code dealing with causally dependent multiple mechanisms. My question is now if you also have a STATA code that would allow me to run an analysis for causally dependent multiple mechanisms? If not is there another way of running the same analysis
with the STATA? That is, which calculations would I need to do in order to analyse my data for potential post-treatment confounders?</div>
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<div>I would much appreciate your response as I currently do not know who else could help me with it.</div>
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<div>Best wishes,</div>
<div>Alina Feinholdt</div>
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<div style="font-family:Tahoma;font-size:13px;text-align:left"><i>PhD candidate</i></div>
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<div style="text-align:left"><span style="font-size:10pt"><i>Universiteit van Amsterdam</i></span></div>
<div style="text-align:left"><span style="font-size:10pt"><i>Kloveniersburgwal 48,</i></span></div>
<div style="text-align:left"><span style="font-size:10pt"><i>1012 CX Amsterdam, </i></span></div>
<div style="text-align:left"><span style="font-size:10pt"><i>The Netherlands</i></span></div>
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