Econlinks

• McCloskey and Ziliak vs. Hoover and Siegler, from the (very welcome, long overdue...) statistician's perspective. Gelman has extremely interesting points and I agree with most of them, except that I think (and he partially admits...) he does not know much (euphemism...) about the rational addiction & co literature, so let us leave that point out, shall we (in any case it is not related to the matter at hand)...

• Massively collaborative mathematics (via Terry Tao). I count myself an idealist when it comes to such ideas, just as the author of this post, and there are some well argumented points therein, but... my more recent economics background takes me back to earth. So here's one main reason (there are others, linked particularly to the nature of problem chosen to be solved by way of such "massive collaboration") why I think this will not work out (in Maths or any other science, for that matter, Econ included): the costs (particularly time and effort to follow such discussions, not to mention trusting the person-- if at all-- to monitor it all etc) would far outweigh the benefits. Unless the persons participating are far more efficient than the average (in time management & co) and, perhaps crucially, are not concerned with career building any longer... Somebody like Terry Tao perhaps, to keep it to Maths, though he does not seem overenthusiastic either :-).

• Monty Python should get Honorary PhDs in Economics. Their idea is already better than Radiohead's marketing experiment; hence, we have high expectations for even more daring moves in this direction, within the arts & entertainment world and beyond.

• Nature editorial on a "scientific responsibility index". I think some of these indices do not have to do so much with the aggregate, such as a country/nation dimension (for instance, it is in my opinion almost ridiculous to claim that researchers from/in a certain country ought to feel in any way tarnished by other co-national researchers'--could be from other fields, other times etc-- lack of ethics, and thus by an eventual 'country science ethics index'...), but otherwise the article is on the right track... Via Razvan, on Ad Astra.

• The so much en vogue Bailout Game.

• George Soros, with an interesting (and financially very informative) FT article entitled "The game changer" (plus an account of how well his own financial operations fared). Obviously I do not agree with all his points, for instance one paragraph I do not fancy is the following: "As it is, both the uptick rule and allowing short-selling only when it is covered by borrowed stock are useful pragmatic measures that seem to work well without any clear-cut theoretical justification." In fact, I think it is precisely because we do not have clear-cut justifications and lent ourselves too much to "pragmatic" experimentation, of whatever kind, is why we ended up here. One new such 'pragmatic' rule is not necessary better than a previous such 'pragmatic' rule :-). Thanks to Paul for the link!

Peer review how-to

The Science edition from the 4th of Jan had two extremely interesting short essays published in the "letters" section. You can read them both on the first page of this PDF.

The first of those two letters, by William F. Perrin, raises a well known problem in the academic publishing area, namely the serious difficulty of finding reviewers for scientific articles submitted to journals. Next to the grave implications mentioned by Perrin in the letter (editors will often have to settle for less-knowledgeable reviewers and reviews of lesser quality), one other obvious consequence is that the refereeing period increases considerably. I've faced myself this problem for one of my papers submitted for publication, where, after an incredibly long period without hearing anything, I've contacted the editor of that journal only to find out that no less than 5 persons he had initially approached have refused to review the manuscript and worse, one of the two who had accepted, has eventually given up after a few months-- leaving the editor with no option but to search for a new referee.

How are we to approach this dilemma, what are possible solutions one can think of? Perrin capitalizes on the academic ethics: "Doing a fair share of peer reviews should be a recognized and expected part of the job for scientific professionals; it should be written into the job descriptions of salaried scientists and be considered in evaluating junior faculty for tenure. The caution should be "Publish and review, or perish"". While I agree with Perrin's normative ideal, I think this would not be sufficient to provide the right incentives: after all in most high-level academic places, the above is implicitly understood as part of the job of professional scientists already; I doubt any of these scientists would disagree with Perrin, should they be asked. The problem is that such a rule cannot be really enforced since, given that the peer-reviewing is typically done under anonimity, there is no way to tell how many times a potential referee refuses to peer-review. And simply setting a rule concerning a minimum of reviews (e.g., one scientist should have 12-16 reviews per year, according to the back-of-the-envelope computation of Perrin) is really not going to work for related reasons (one cannot proxy how many proposals for refereeing one particular scientist receives in a given time period, not to mention that it is very likely that this variable has a high variance etc.). So, can we do anything else? And here's something I see as straightforward solution: why not pay the referees every time? The obvious way to ensure this is sustainable is to ask a submission fee for every paper submitted (some scientific journals practice this submission-fee policy already) and to use most of that fee to pay referees, if they provide a referee report in a requested amount of time. I am not aware of any study that compares paid-referee-reports with non-paid-referee-reports practices (they both exist nowadays, though to the best of my knowledge the former is rather exceptional) in terms of: a. the length of the period necessary to obtain two or three referee reports, the number depending on the policy of the journal; b. the quality of the reports. My intuition would tell me that the reviewing period would be shortened considerably and that the editor would find referees faster under the pay policy; I doubt the quality of the reports would increase under the pay system, but this remains an empirical question (e.g, one can expect people to deliver higher quality reports under the pay system, in order to be asked again to referee, but at the same time one could potentially expect people to accept to review even when they know they could not do a good job reviewing that particular paper because of real lack of time, expertise etc.). There are also questions regarding the amount and form of this eventual payment etc., but those are already second-stage considerations and would not present insurmontable problems (e.g., if it turns out one has to pay the referees more, the submission fees could be raised etc.).


The second letter tackles the fact that reviews might have become too critical and demanding (e.g., to the point of virtually demanding the entire paper be rewritten), a view shared by many others (and here see also Preston McAfee's idea of revolutioning the reviewing policy of the journal he's been recently assigned to as editor). Robert S. Zucker makes some great points in his letter to Science (they might seem obvious, but you'd be surprised how many times they are grossly violated in actual practice), which I take ad litteram below and place in a list format-- 'a peer-review how-to':

• Reviewers should highlight a paper's strengths and weaknesses, but they need not delineate strengths in very weak papers nor stress minor weaknesses in strong papers.
• Reviews should be prompt and thorough and should avoid sharp language and invective.
• [Do not] reflexively demand that more be done:
  • Suggest an additional experiment, further analysis or altered specification, but do not make publication contingent on these changes.
  • If the conclusions cannot stand without additional work or if the evidence does not distinguish between reasonably likely alternatives, recommend that the editor reject the manuscript.
• Seek a balance among criteria in making a recommendation:
  • Do not reject a manuscript simply because its ideas are not original, if it offers the first strong evidence for an old but important idea.
  • Do not reject a paper with a brilliant new idea simply because the evidence was not as comprehensive as could be imagined.
  • Do not reject a paper simply because it is not of the highest significance, if it is beautifully executed and offers fresh ideas with strong evidence.
• Step back from your own scientific prejudices, in order to judge each paper on its merits and in the context of the journal that has solicited your advice.

Importance of early environment for children's cognitive development: Bucharest Early Intervention Project

A very important and welcome study on the cognitive recovery of socially deprived young children, using a randomized controlled trial with young orphans from Bucharest, Romania, has been published in Science, on the 21st of Dec '07. You can read the abstract here.

As you can see from the abstract linked above, none of the authors is affiliated with a Romanian institution; however, it comes clear from the full text that they were greatly helped (and initially invited to do the study) by the Romanian authorities, which is a very pleasant surprise; I must confess that I would have been (and in fact, still am, to a certain degree...) very pessimistic inasmuch cooperation of Romanian authorities is concerned in such cases (perhaps this one here went through just fine given the huge importance of the topic and continuing international pressure etc.). I copy-paste below the fragment depicting the chronological interaction with the Romanian authorities in context and parts of the crucial ethical considerations for such a study:

First, our study was initiated at the invitation of the then–secretary of state for child protection in Romania and was approved by the local commissions on child protection in Bucharest, the Romanian ministry of health, and, in 2002, by an ad hoc ethics committee comprising appointees from several government and Bucharest University academic departments. It was therefore done with the participation and approval of local authorities. Second, the institutional review boards (IRBs) of the home institutions of the three principal investigators (the University of Minnesota, Tulane University, and the University of Maryland) approved the project. Third, we implemented a policy of noninterference with placement of children in both groups into alternative family care environments, leaving those decisions to Romanian child protection authorities (according to Romanian law). The only exception to the noninterference rule was that we ensured that no child placed in foster care as part of the randomization process would ever be returned to an institution [...]. Fourth, after our preliminary results began to suggest positive benefits of foster care, we held a press conference to announce the results of our investigation. Key ministries in the Romanian government were invited to attend and sent representatives to this meeting. The then–U.S. ambassador to Romania (who was briefed in advance about our findings) gave the opening remarks at the conference. Fifth, although the usefulness of clinical equipoise is controversial among bioethicists [...], a reasonable interpretation of clinical equipoise supports the research design in this project. Clinical equipoise is the notion that there must be uncertainty in the expert community about the relative merits of experimental and control interventions such that no subject should be randomized to an intervention known to be inferior to the standard of care [...]. Because of the uncertainty in the results of prior research, it had not been established unequivocally that foster care was superior to institutionalized care across all domains of functioning, especially with respect to how young children initially placed in institutional care function when placed in foster care as compared with children who remain in the institutional setting. Moreover, at the start of our study there was uncertainty about the relative merits of institutional and foster care in the Romanian child welfare community, with a historical bias in favor of institutional care. Additionally, given that the study was invited by Romanian authorities and conducted there, with the aim of guiding child welfare policy in Romania, it made sense to assess the study in view of the local standard of care, which was institutional care. The study also presented no more than minimal risk to the subjects; specifically, children assigned to the IG continued to receive the same care as if the study had not been conducted, and the measures we used have all been used for many years in developmental science research. Lastly, we were aware from the outset of the policy implications of our work, and as the study progressed we made our results available to government officials and child protection professionals. Indeed, several years after our study began, the Romanian government passed a law that prohibits institutionalizing children less than 2 years old, unless the child is severely handicapped.

Despite the small scale of the study, the findings have enormous implications and confirm in several ways earlier research on the importance of the very early (and "very early" should be interpreted as crucial here!) environment for children's subsequent cognitive development. I quote below the summary of the findings of the Science report and the authors' conclusions regarding implications for child welfare:

Three main findings emerge from this study. First, as we have previously reported [...], children reared in institutions showed greatly diminished intellectual performance (borderline mental retardation) relative to children reared in their families of origin. Second, as a group, children randomly assigned to foster care experienced significant gains in cognitive function. Lastly, at first glance our findings suggest that there may be a sensitive period spanning the first 2 years of life within which the onset of foster care exerts a maximal effect on cognitive development. However, a closer reading of our analyses suggests a more parsimonious conclusion: That the younger a child is when placed in foster care, the better the outcome. Indeed, there was a continuing "cost" to children who remained in the institution over the course of our study. These results are compatible with the notion of a sensitive period, but discovering whether such a period truly exists or determining the borders that delineate it would likely require a larger sample size with a broader age range at intervention onset.

The results of this study have implications for child welfare because they suggest that placement in families is more advantageous for cognitive development in infants and young children than placement in institutional settings. For countries grappling with how best to care for abandoned, orphaned, and maltreated young children, these findings deserve consideration. The results also indicate that previously institutionalized children's cognitive development benefits most from foster care if placement occurs relatively early in a child's life.

I would only add that it would have been great to also deal with the non-cognitive implications of the child early environment, which are possibly even more important than the effect on the cognitive development. There is considerable current research addressing this issue (and a very important chunk of this research is also performed within economics nowadays-- area where I am personally interested in, in terms of future plans of research-- see for instance the very interesting related projects of Jim Heckman and his co-authors, e.g. here, under the headline "Studies in Cognitive and Non-Cognitive Skills"), but, as always, the difficulty rests with implementing such a randomized trial, to start with. Hence, this would have been a great opportunity (perhaps that idea is still pursued and a different study will be/is being published dealing with it); nonetheless, I agree that the initial focus was different and to design and perform this bit already required a lot.

If you want to read more on the topic of this post: the link to the full Science report (you need a subscription to Science to access it). Read also a summary with further comments regarding ethical considerations, on 60-seconds-science (I do not agree with the author's remarks, concluding in 'I’m not sure why this study was necessary', but I leave further discussions here for some other time). Finally, read also a short article on ethical guidelines concerning international research with abandoned children (again, subscription to Science required).

Probability of being a serial killer: the case of Lucia de Berk

Here's a post on an extremely interesting story at the intersection of law, statistics and professional ethics in several disciplines. Inter alia, the issue has been covered in some of the best scientific journals. See for instance a). a report in the Science edition of the 16th of November (you need a subscription to access the PDF); b). a very good report on this case in Nature, January this year; you can read here that PDF (subscription free).

What is this about? One of the most interesting legal cases ever, involving multiple homicide, is now under review by the Supreme Court in the Netherlands. The case deals with the former trial of Lucia de Berk, a Dutch nurse, accused and sentenced to life imprisonment in spring 2003, for the alleged murder of seven hospital patients and the attempted murder on three others, in places where she had worked between 1999-2001. The issue is that there was never direct evidence to implicate De Berk (and she has always denied all accusations): she was condemned solely based on the fact that she happened to be always around when these patients died; basically the courts (an appeal court also upheld the initial verdict) decided that it was very unlikely, essentially only one chance in 342 million, according to the expert statistician who testified at the trial, that so many deaths could have occured accidentally while she was nearby.

What happens now is that the 2003 sentence is being challenged by several scientists who signed a petition to re-open the case (this is what the Supreme Court needs to decide on, after last months a justice department panel indeed recommended that the case be reopened). Richard Gill, a Leiden University mathematician and organizer of the petition, states that the previous conclusion, leading to the condemnation of De Berk, is based on "every statistical mistake in the book". Gill and others concluded that the previous statistical testimony was based on an incorrect analysis and that in fact the probability estimated earlier, of 1 in 342 million, is in fact as low as 1 in 48 or even 1 in 5, which are very unlikely to meet the criterion of "beyond reasonable doubt" needed for a criminal conviction. Here's the website of Gill dedicated to this case (with his detailed discussion of the statistical aspects in this case here and Gill's synopsis/reconstruction of the case + other interesting details here). There is even a whole book criticizing De Berk's conviction on scientific procedure, by Ton Derksen , a philosopher of science from the University of Nijmegen. Mark Buchanan, who wrote about the case in Nature (see the link above) summarizes the legal essence of the argument this way: "The court needs to weigh up two different explanations: murder or coincidence. The argument that the deaths were unlikely to have occurred by chance (whether 1 in 48 or 1 in 342 million) is not that meaningful on its own - for instance, the probability that ten murders would occur in the same hospital might be even more unlikely. What matters is the relative likelihood of the two explanations. However, the court was given an estimate for only the first scenario."

This is certainly not an easy case, despite the fact that it is not the first one that might involve wrong statistical evidence in a criminal sentence (the Nature report linked above also mentions another high profile case involving misuse of statistics, the case of Sally Clark, from 1999, in Britain). My opinions are the following. Firstly, I strongly believe that the Dutch Supreme Court has more than sufficient basis to re-open De Berk's case and carefully re-analyse all the previous evidence (I've obviously signed the petition as well). Further, one can only hope that a wrong verdict is overturned swiftly in De Berk's case, should the petitioners be right (and then I wouldn't want to be in the place of the 'expert statistician' who testified to start with, although it is true, as can be read on Gill's discussion, that this expert "always insisted that his analysis only showed that the observed coincidence could not be due to pure chance, not that Lucia caused the the deaths"; moreover, this expert himself wants the case to be reopen; but the scientific flaws would still be there, if the petitioners are right.). More generally, one can only hope that science will be used with the greatest care in any legal processes, especially criminal ones, given the extreme emotions and stakes typically involved (but not only: science has to be done properly, anytime, anywhere, anyway...).

New, old and (always) exciting in science

Shortly back to blogging after quite a while... Today I'll drop a few lines about some interesting science pieces, both new and old, but anytime exciting. Of course the selection is mine.

• For quite a while now, I've been listening every week (really!) to the Scientific American (SCIAM) podcast new episodes. It is absolutely worth it and it is very practical as well since you can do it in a break (from reading, programming or any other research or non-research activities). Steve Mirsky, the host, manages to keep a perfect balance between general and specific, with humorous interludes now and then, hence all these subjects are generally available to the large public- provided of course a minimum interest in science (which, by the way, might be induced this way)- and they are never boring! One of my favourites so far is a recent entry from May 3 which is largely dedicated to a very nice informal interview with 2004 Physics Nobel Laureate Frank Wilczek (he shared the prize with other 2 researchers). Among other things you'll find out the basics about the weak and strong forces acting in the nature, super symmetry, but also about the call received at 5:30 in the morning from Stockholm announcing Prof. Wilczek that he received the Nobel prize. One small correction though to be made to Prof. Wilczek's story (nothing on the technical side though :-)): Professors Gerardus van 't Hooft and Martinus Veltman received the Nobel in 1999, not 1998. I was actually present at the ceremony dedicated for this great event within the Utrecht University (as an aspiring Theoretical Physicist at that time!) and later attended a very interesting lecture by Prof. van 't Hooft, at the University College Utrecht (in which I remember he also talked about Frank Wilczek's research and the fact that Wilczek and his co-laureates were just a bit- in the annoying sense- faster than him in publishing on the extension of his previous research with Veltman, that won them the 1999 Nobel ). All right, just one more digression here: you should also check out Betsy Devine's (the wife of Frank Wilczek) page about their Nobel adventures but also a bunch of Funny Ha-Ha and Funny Peculiar things (btw, the Guy Goma- BBC entry is absolutely hillarious).

• Prof. Harold Shapiro's recent address at the AAAS is an important advice addressed to all scientists:

  Humility remains an important human characteristic even for scientists. [...] Scientists need to recognize, for example, that other areas of human activity also have been critical participants in this vast humanitarian effort, providing quite different but equally imaginative, equally creative and equally valuable contributions to the evolution of human societies. The evolving literary, artistic, political institutions and imaginations have also been central to this humanitarian enterprise, to say nothing of the world’s great religions, whose narratives have done so much to sustain human efforts over such a long period of time. More on this address.

• In the latest issue (vol 96, no.2, 2006) of the American Economic Review, Gregory Mankiw is addressing a letter (you need to have a subscription to AER) to new Fed Governor Ben Bernanke. I like a lot the part about the fact that the Fed boss should be as boring a public figure as possible (and I agree!):

  My recommendation to you is to become as boring a publig figure as possible. For an economist, boring is an occupational hazard. For a central banker, however, it is just the ticket. The central bank's job is to create stability, not excitement. One way of doing that is to increase confidence in the institution of the Federal Reserve and to educate the public that the institution matters more than the individual who happens to be leading it at the moment. It would be ideal if, after a long, succesful tenure, your retirement as Fed chairman were a less momentous event than your arrival.

• a US Senator decided to question and probably oppose (you need subscription for Science to read the whole article) any further NSF funding for social science (and target all funding for natural sciences and engineering). While I think USA social scientists could (and should) do a much better job in explaining what they are doing and why they are doing what they are doing, I also think she is more than exaggerating and simply making a show. What is amazing though is that apparently social scientists present at the audience could not answer her immediately to questions which show her being parallel to science, such as (taken from one of the Science numbers) "Why is the NSF funding a study of a women's cooperative in Bangladesh? Why are US taxpayers footing the bill for efforts to understand Hungary's emerging democracy? And why are social scientists even bothering to compile an archive of state legislatures in a long-gone era when those legislators choose US senators (ok, that might actually have a direct answer since it could prove that US senators back in those times were having somewhat higher IQ's)." On the other hand, no answer from the scientists point of view (remember Shapiro's point above) seems even more foolish and I don't really want to think of what it indicates.

• and finally for now (simply a time constraint, otherwise I could go on ad infinitum), an older, nonetheless very interesting and definitely very actual article. It concerns new developments in trying to explain circumstances under which people might cooperate for contributing towards a public good and how the option to punish detractors can help. Just imagine you could immediately punish people that avoid paying their mandatory taxes etc, albeit at a cost. Would you do it? This very nice experiment described below suggest you would, even if initially you might not think so. And assumably that this will also eliminate any cheating behavior in the long run.

Understanding the circumstances under which people cooperate is a complex matter that has challenged evolutionary, behavioral, and economic researchers for decades. Particularly difficult to deconstruct are so-called "public-goods" problems, which involve situations in which individuals incur a cost to create a benefit for the group (modern examples might include recycling, voting, or giving blood). In a Report inthe 7 Apr 2006 Science, Gürerk et al. (http://www.sciencemag.org/cgi/content/short/312/5770/108 ) offered new insight into what drives cooperation in large groups. In an experimental game, individuals were asked to choose between two artificial societies. In one society, players could contribute money to a group project and the sum of all contributions was divided evenly amongst all players. The second society was similar except that after players contributed, they were allowed to pay to punish (reduce the payoff of) players who did not contribute equally. After each of 30 rounds of play, players were allowed to choose their society for the next round. The researchers found that most people initially picked the first society, which does not permit punishment and tolerates freeloaders. But as successive rounds of the gamewere played, cooperation broke down in that group and nearly all players came to appreciate the greater rewards of the other society, which enabled higher total payoffs despite the individual cost of punishing freeloaders. An accompanying Perspective by J. Henrich (http://www.sciencemag.org/cgi/content/short/312/5770/60 ) highlighted the study.

Deadly Medicine

The Science edition from the 24th of February also describes an online collection of "Twisted Science" exibits. It is about the online version of an exhibit of "deadly medicine" at the U.S. Holocaust Memorial Museum in Washington, D.C., documenting distorted science practices by Nazi scientists and doctors, in order to justify their "racial hygiene" policies, materialized in the murder of millions of Jews and other people considered inferior. Profiles of several prominent scientists involved (some of them- incredibly- resuming or even improving their careers after the war) are also briefly presented. A very welcome initiative of the US Holocaust Memorial Museum- and clearly a must for any scientist and not only- as lesson of what horrific ends unsound and purposely unethical scientific reasoning can be used for.

This automatically links with something else: how on Earth can we still have those humanoids with no brain arguing that the Holocaust did not take place, despite every evidence pointing to that? A recent such case is the one of "historian" David Irving. I guess the most important thing here is that the subject himself (partially) admitted - at the very end of the day- his errors, and not so much the legal punishment (I have doubts whether the enactment and enforcement of such legislation instead of complete freedom of speech BUT concerted and sustained ex-post criticism of, particularly in this case, all the academic community, and eventual academic downgrading based on scientific grounds of the subject, is more efficient). Something certain - unfortunately- not to happen (admitting errors and apologizing) in the case of a certain islamic president (or for that reason, the supreme leader of that state).