{"id":592,"date":"2012-12-27T14:30:19","date_gmt":"2012-12-27T21:30:19","guid":{"rendered":"http:\/\/www.mii.ucla.edu\/causality\/?p=592"},"modified":"2012-12-27T14:30:19","modified_gmt":"2012-12-27T21:30:19","slug":"causal-inference-symposium-heckman-and-pearl","status":"publish","type":"post","link":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/2012\/12\/27\/causal-inference-symposium-heckman-and-pearl\/","title":{"rendered":"Causal Inference Symposium: Heckman and Pearl"},"content":{"rendered":"<p><strong>Judea Pearl Writes:<\/strong><\/p>\n<p>Last week I attended a causal inference symposium at the University of Michigan, and had a very lively discussion with James Heckman (Chicago, economics) on causal reasoning in econometrics, statistics and computer science. Video and slides of the two lectures can be watched here: <a href=\"http:\/\/www.psc.isr.umich.edu\/pubs\/video-tapes.html\">http:\/\/www.psc.isr.umich.edu\/pubs\/video-tapes.html<\/a><\/p>\n<p>In the QA session (not in the video), I described the problems of transportability and external validity, and their solutions according to:<br \/>\n<a href=\"http:\/\/ftp.cs.ucla.edu\/pub\/stat_ser\/r372.pdf\">http:\/\/ftp.cs.ucla.edu\/pub\/stat_ser\/r372.pdf<\/a><br \/>\n<a href=\"http:\/\/ftp.cs.ucla.edu\/pub\/stat_ser\/r390.pdf\">http:\/\/ftp.cs.ucla.edu\/pub\/stat_ser\/r390.pdf<\/a><\/p>\n<p>Heckman asked: What makes this problem different from the one that economists solve routinely &#8212; when they find a new distribution that differs from the one they estimated, they simply re-estimate the parameters by which the two differ and keep those on which they agree.<\/p>\n<p>My answer stressed three facts that should be kept in mind when dealing with &#8220;transporatability&#8221;:<br \/>\n1. We cannot speak here about differing &#8220;distributions&#8221; because transportability is a causal, not statistical problem. In other words, what needs to be re-estimated depends not on the two &#8220;distributions&#8221; but on the causal story behind the distributions.  (This is shown vividly in Example 2 of <a href=\"http:\/\/ftp.cs.ucla.edu\/pub\/stat_ser\/r372.pdf\">R-372<\/a>).<\/p>\n<p>2. We are now dealing with the task of transporting &#8220;experimental findings&#8221; (e.g., causal effects), not distributions, from a place where they are available to a place where they are not estimable.<\/p>\n<p>3. We cannot even speak about re-estimating &#8220;parameters&#8221; because the problem is entirely non-parametric. <\/p>\n<p>More comments on audience questions will follow.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Judea Pearl Writes: Last week I attended a causal inference symposium at the University of Michigan, and had a very lively discussion with James Heckman (Chicago, economics) on causal reasoning in econometrics, statistics and computer science. Video and slides of the two lectures can be watched here: http:\/\/www.psc.isr.umich.edu\/pubs\/video-tapes.html In the QA session (not in the [&hellip;]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,13,16],"tags":[],"class_list":["post-592","post","type-post","status-publish","format-standard","hentry","category-discussion","category-economics","category-general"],"_links":{"self":[{"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/posts\/592","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/comments?post=592"}],"version-history":[{"count":0,"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/posts\/592\/revisions"}],"wp:attachment":[{"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/media?parent=592"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/categories?post=592"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/causality.cs.ucla.edu\/blog\/index.php\/wp-json\/wp\/v2\/tags?post=592"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}