5/4/15


Franklin G. Miller, Luana Colloca, Robert A. Crouch, Ted J. Kaptchuk, The Placebo: A Reader, Baltimore, Johns Hopkins University Press, 2013

The "reader" genre is becoming more difficult today than in any previous decade: in the pre-digital repositories age, compilations granted easy access in print to papers, otherwise difficult and expensive to obtain. Nowadays, we will only buy such compilations if they combine an excellence of editorial taste and readability that beats the temptation of downloading our own selection directly from a journal archive.  In this regard, I must admit that the editors of this placebo reader have succeeded in producing a volume worth buying. 
  
The book compiles 52 papers on the placebo effect divided in four sections. Eight articles feature in the first one, on the concept and significance of the placebo effect. 30 more are classified under four headings in the second section, experimental studies of the placebo effect: the headings are pioneering efforts, psychological mechanisms neurobiological mechanisms and contextual factors. The third and final section, on the ethics of using placebos, presents the last 14 papers about research and clinical practice. The papers are chosen and presented in such a way that the compilation reads as a historically motivated introduction to our current understanding of the placebo effects.
The uninitiated reader will probably appraise the placebo as a treatment without active ingredient that nonetheless makes (some) patients improve (e.g., sugar pills). As Ted Kaptchuk observes in his introduction, this is a relatively modern concept. Using placebos implies that we are somehow able to differentiate between effective and ineffective treatments and such a distinction could only be properly quantified with the emergence of clinical trials in the 1940s. There was an initial enthusiasm about the healing power of placebos that gradually vanished with more sophisticated analyses (documented in the anthology with papers from the 1980s and 1990s): the statistical data of most clinically relevant variables tend to regress from extreme values (disease) to the mean (health) of their distribution, and we can only take properly into account this spontaneous improvement if we compare in a trial a group of patients treated with a placebo with another one with no treatment at all. Taking all this into account, the mainstream view today is that the only placebo effect statistically documented appears when measuring patient reported outcomes, such as pain. The papers complied in the first section document how this view emerges.   

It is worth recalling here that clinical trials were introduced in medicine as a yardstick for assessing the effective of treatments without a real causal understanding of why they were effective. E.g., the underlying mechanism of the antidepressant action of benzodiazepines was understood in the 1970s almost two decades after the first trials, when Valium was already one of the best selling drugs of the past century. Trials often guided our investigation of such mechanisms, showing how a drug operated under a range of different circumstances. In this respect, placebos would be like any other treatment: we lack a "robust and comprehensive" (Kaptchuk) theory, but there is a growing body of experiments documenting how placebos work. First, there are psychological mechanisms, among which the most prominent are behavioral conditioning (often unconscious) and expectations (usually conscious) induced verbally or, e.g., through social observation. Through a number of experimental designs we learn how these mechanisms operate and the physiological responses they trigger (e.g., the release of opioids). Then there are neurobiological mechanisms underlying placebo, illustrated in a number of experiments supported by various forms of brain imaging. Finally, there are contextual factors, often related to the interaction between physicians and patients in a given setting. 

Half of the third section, on the ethics of placebo, hinges on clinical trials as well. Here the approach is mostly methodological: to what extent do we actually need placebo in order to ground solid experimental designs? More precisely, do placebos provide a real benchmark to gauge the efficacy of a new treatment? The obvious ethical implication is that, were the response negative, there would be no reason to use a placebo instead of an active treatment (if there was one) as a comparison. Moreover, since placebos partly operate through the patients' expectations, it is an open question how much shall we deceive them about the (lack of) treatment they are receiving. There is some evidence about placebos working when they are almost openly presented as such. And there is also evidence, presented in the second half of this section, about physicians prescribing placebos outside trials and a discussion about the ethics of such a practice. 

The book closes with a paper by Miller and Colloca, two of the editors of the volume -there are 10 papers co-authored by, at least, one of the members of the editorial team, so there is no pretence of neutrality in the compilation. Their conclusion summarizes somehow the agenda this volume seems to promote: for certain conditions, placebo might actually be an effective treatment; if there is evidence gathered in well-designed trials and the nature of the treatment is properly disclose to the patient, it is acceptable to prescribe it. Hence, acupuncture for pain relief in various conditions could be legitimately prescribed on evidence-based grounds. But, for the time being, no other placebo meets such a scientific standard. 

On a more general note, I'd say that a major thread in this book is that it contributes evidence to ground quite a paradoxical intuition: the mere act of diagnosing a patient and administering a treatment (at least for a few conditions) has effects that break the equivalence between "placebo" and "lack of treatment". My favorite illustration in the book is an trial with Kaptchuk as first author (pp. 226-32) testing different "treatments" for the irritable bowel syndrome: being in a waiting list (measuring patients' response to observation and assessment); sham and real acupuncture (placebo) and an augmented placebo: the needling was accompanied by a scripted positive interaction with the physician. The trial showed that these three components add up progressively, reaching a maximum effect with the augmented placebo, reaching a clinically significant effect in the treatment of the condition. 

In the traditional approach to trials, the preferences of patients were considered a source of bias, since they could make a difference on the outcome. The evidence gathered in placebo research shows that, except for pain, there is no trace, so far, of a significant effect of the patients’ expectations on the treatment outcome. Perhaps this volume should prompt us to reconsider the status of blinding as a debiasing method: its usual justification is precisely that it controls for placebo effects derived from the patients preferences about treatments. Making them entirely alike breaks any systematic correlation between such preferences and the treatment outcome. But if there is no placebo effect for most conditions, perhaps we should reappraise blinding as a method to enforce the treatment protocol: since some patients would drop off the trial if they knew they were receiving an unwanted treatment, blinding secures their compliance, independently of the placebo effect. Clinical trials are indeed strategic interactions between agents with different, sometimes conflicting, interests that we should take into account in designing the trial. Controlling for some of these interactions (more than the placebo effect) might be the real justification of masking devices. In one of the compiled papers, R. Temple and S. Ellenberg contribute another argument in this same vein against active-control equivalence trials (p. 258): if you compare a drug against placebo, you have every incentive to enforce compliance with the trial protocol, since every deviation will usually reduce the differences between treatment groups, making your drug equivalent to a placebo. If you make a comparison with a standard treatment in order to prove lack of difference, there are weaker incentives to enforce protocol compliance. In other words, placebos may play a role in making both patients and researchers alike play by the rules of the experiment.

Two final positive comments. One surprising feature of this collection is how well it reads: each section is preceded by a short (but incisive) introduction intended as a road map of the papers to come. These are short and clear, and very accessible for the lay reader. The design of the experiments, their findings and the issues they raise are often so puzzling that the collection becomes engaging: I found myself eager to know whether an experiment had passed the test of replication, whether counter-arguments existed, if there was a final word on a topic. The papers are selected and ordered in such a way as to elicit this sort of engagement. Another surprising trait is the size of the volume (10.9 x 8.4 x 0.9 inches): it may initially look difficult to handle (in this age of palm-sized readers), but I found it very pleasant to work with.
{January 2014}

4/3/14

Raffaella Campaner, Philosophy of medicine. Causality, Evidence and Explanation, Bologna, Archetipo Libri, 2012

For more than a decade now, there has been a growing interest in the philosophy of medicine as a scientific discipline. Already in 2005, Raffaella Campaner published a monograph in Italian on causality and explanation in medicine (Spigazione e cause in medicina: un’indagine epistemologica) showing how philosophy of science could be successfully applied to biomedical research. Throughout this decade, Campaner published a series of papers in English on the same topics that are now compiled in the reviewed volume. Most of these papers were originally published in edited collections or journals where medicine was not the central topic, so re-publishing all together in a single volume makes sense for the interested reader. Moreover, the Italian publisher has produced a decently edited but inexpensive book, so all in all philosophers of medicine should welcome it.

Campaner has gathered here 9 papers plus an introduction. Their structure is somewhat similar: the author presents different philosophical positions (mostly on causality, but also on explanation) and proceeds to illuminate them with medical case studies, arguing on this basis for her own claims. The reader will find thus an introduction to the following accounts on causality: mechanistic (Salmon, Machamer-Darden-Craven, Glennan), interventionist (Woodward) and manipulative (Price and Menzies), with a brief digression on counterfactuals (Lewis). Despite featuring on equal rank in the book’s title, we do not find introductory accounts of philosophical theories of explanation and evidence. Campaner considers instead plenty of medical explanations and evidences and see how they may fit in the different philosophical accounts of causality presented. Among her case studies, two of the most detailed are on deep brain stimulation (a therapy for Parkinson’s disease) and anti-AIDS treatments. Campaner deals also in several papers with epidemiological and psychiatric causation.

The book puts forward a pluralistic perspective on causation, showing how in actual medical practice we may find all the above mentioned approaches complementing (rather than competing with) each other. The choice often depends on the methods implemented and the context of implementation. The author does not try to construct a principled argument for causal pluralism: as she acknowledges, “lots of work is still to be done before a plausible and coherent view will be settled on and shared” (p.60). The strength of her argument is empirical: there is no evidence that a “one size fits all” concept of causation can cope with the diversity of causal approaches at work in medical practice. However, Campaner also draws on a conceptual insight emerging from this diversity: diseases would be multilevel phenomena (ranging from cells, molecules, tissues upwards to the whole organism) and medicine (siding here with Schaffner, p. 11) would be a set of middle-range theories coping with them. Campaner adopts here a sort of meta-philosophical instrumentalism regarding such deeply entrenched methodological divides such as the one opposing reductionism and anti-reductionism: as she illustrates in chapter 7, both strategies have been fruitful in medicine and both might make sense contextually. In this respect, I think is worth noticing how difficult it is to sustain even moderately pluralist stances about medical causality such as the Russo-Williamson thesis –according to which we would need mechanistic and probabilistic evidence to properly ground causal discoveries. Yet, as Campaner argues in chapter 2, medicine has been quite capable of making progress without mechanisms and yet, when we have them, we often need manipulative evidence, in addition to statistics, to properly ground them.

Campaner constantly reminds us that her pluralism does not “amount to treat all available methodological options as equal in value” (e.g., p. 133), but the book focuses mostly on cases where there is more complementarity than straightforward competition between the alternatives considered and all of them are worth, at this point in time, of scientific consideration. Historically, though, medicine has not been as peaceful as it might seem today. In The Rise of Causal Concepts of Disease (2003), for instance, K. Codell Carter has forcefully argued that scientific medicine began with the adoption of the etiological standpoint, the view that every disease has a single cause which is both necessary and sufficient for the disease, showing how this approach was crucial for progress in its treatment. Even today, I would say that medicine is not really pluralist when it comes to decision making about new therapies: we still rely on their success in randomized clinical trials as a rule. Of course, trials might be interpreted from different causal stances, but not all of them are equally captured in their design: mechanistic knowledge, for instance, does not currently qualify the value of a trial in most hierarchies of medical evidence.  In other words, as of today, philosophical pluralism about causation may faithfully reflects the way medicine is practiced, and methodological diversity may be in itself a fruitful research strategy. But I think Campaner’s claim would have been more balanced if it also considered cases in which there was open disagreement about causality between competing research agendas.

My major qualm with this volume is that the papers were not edited for the compilation. Reading it from cover to cover might be a bit reiterative sometimes since the same items are often revisited in different chapters. However, it makes it really suitable for use in undergraduate courses, in particular when teaching philosophy of science to medical students, since most concepts are explained in an accessible manner detail and illustrated with theories they will be certainly familiar with. The name index at the end is particularly helpful in tracing different approaches throughout the book and keeping the original abstracts at the beginning of each chapter is equally useful to guide the uninitiated reader. Campaner’s is thus not only a good philosophy of science in practice book, but also a very accessible book in itself.

{October 2013}
{International Studies in the Philosophy of Science 27.4 (2013), 456-458}

A. Briggle & C. Mitcham, Ethics and Science: an Introduction, Cambridge, Cambridge University Press, 2012

I don’t know if this qualifies as a conflict of interests, but I must admit I volunteered to review this book because I am teaching a course on ethics and science and there are not many comprehensive textbooks available. A strength of Briggle and Mitcham’s volume that immediately caught my eye is that it brings together an updated introduction to ethics, philosophy and the political sociology of science.  Chapters 2-7 cover ethical concepts and theories, research ethics (codes, investigation with humans and animals), norms in science and recent naturalist approaches to ethics. Chapters 9-10 deal with the main issues in science policy. Chapter 11 discusses the broader connections between science and culture and the 12th and final chapter analyzes ethics and engineering.

The structure of the chapters is clear: they all open with a quick case presentation, followed by several sections and a final summary, plus a closing case study with questions and readings for further reflection. There is a general list of references at the end, together with a complete subject index and addresses for ethics codes and declarations. All in all, Briggle and Mitcham’s volume has everything one would in principle expect from a textbook. However, I am not quite sure about how to make the best of it in class. 

The authors do not take anything from granted, so their presentations are as introductory and accessible as possible. This should make it particularly accessible to science and engineering students, their most likely target. In order to make it even easier to read, the authors often adopt an informal narrative tone, in which the case is presented as it unfolded historically, highlighting landmarks, often in a casual manner. Briggle and Mitcham rarely take an opinionated stance: we find the standard account on most topics. But it is sometimes simplified to a point that I was left wondering what use we can make of it in order to assess real world dilemmas. For instance, on page 45, we learn how virtue ethics is relevant for science. First, through an analogy between virtue ethics and virtue epistemology. Then, virtue ethics would also highlight “the importance of training processes and mentor–mentee relationships”, so often neglected in Big Science. Finally, virtue ethics can be used to object against “the wisdom of pursuing certain physical or cognitive enhancements”.

But, in fact, there is no other mention in the book of virtue epistemology and I guess most uninitiated readers won’t make much sense of its relevance for science in just one paragraph. I was left wondering why training processes are more defensible (or interesting) from virtue ethics than from any other approach, or why would virtue ethicists would be more opposed to cognitive enhancement than, for instance, a deontologist. I am not saying that such tenets cannot be defended, but rather that we do not find full-fledged arguments for any of them. 

This is just an instance of a problem I found throughout the book: the reader gets acquainted with plenty of interesting topics, but we rarely find a detailed discussion of any of them. This might just be the expression of my own preferences, but I think that the ultimate goal of a course on ethics and science would be to make the student capable of arguing his/her case as thoroughly as possible. For Briggle and Mitcham, I would say that the goal is rather to increase the student’s awareness about every contentious point in the intersection of ethics and science (and these are many). It is interesting to notice that chapters do not have exercises targeting directly their core points, but rather sets of questions on the closing case studies. The questions are often very open (e.g., “to what extent was this morally justified?”) and no template is provided to answer them. 

I guess that my concern might be shared both by the analytic philosopher and the STS scholar: if the former would care about the arguments not being fully developed, the latter would surely miss the many details that articulate the best case studies in STS. The many vignettes illustrating each chapter are certainly engaging, but I think it would have been instructive to present more thoroughly some cases, showing in detail how we can address them from various perspectives. 

Despite this concern, I think that the material provided in this book is so rich and updated that it may be worth trying it in class, at least as a starting point. Given how quickly this field evolves, I guess it is better to make the most of a textbook now that it is fresh and test it as thoroughly as we can, in order to see if anyone comes up with a different alternative. It is probably not easy.

{May 2013}

24/3/13


U. Mäki, ed., Philosophy of Economics [Handbook of the Philosophy of Science, vol. 13], Amsterdam, Elsevier, 2012, 903 pp. 

Uskali Mäki’s latest edited collection, Philosophy of Economics, appears as the 13th volume in the Handbook of Philosophy of Science, an Elsevier series presented by its editors as “the most comprehensive review ever provided of the philosophy of science”. Three of the seventeen volumes are devoted to social disciplines: apart from economics there is another one for linguistics, and a joint volume for sociology and anthropology. As Mäki points out in his general introduction, economic methodology is closer today to “frontline philosophy of science” (p. xv) than ever before in its very short life as an independent field. This volume marks its coming of age, and it should be celebrated as such.
Reviewing a nearly 1000 pages volume in about 1000 words seems not easy, so let me try to grasp its significance through a comparison with its obvious predecessor The Handbook of Economic Methodology, co-edited by Mäki, John Davis and Wade Hands for Edward Elgar in 1998. This latter was based on short entries, while the 2012 volume consists of regular size papers. Rather than discussing the content of every one of them –and for the suspicious reader, yes, I spent my Christmas break going through it from cover to cover–, I will try to see what this book as a whole reveals about the philosophy of economics as it is cultivated today.
We should notice first that 12 of the 29 authors in the 2012 volume featured already in the previous installment and 9 of them write on almost the same topics: Mäki on realism, R. Backhouse on Lakatos, M. Morgan on models, K. Hoover on causality, H. Kincaid on economic explanation, W. Hands on the positive-normative dichotomy, C. W. Granger on economic forecasting, A. Spanos on econometrics and V. Vanberg on rational choice and rule following. As the reader may guess, most of these pieces take stock of decades of reflections on each topic and sometimes provide real primers on the author’s views. For example, Spanos’ 70 pages paper on “the philosophy of econometrics” is, in fact, an excellent introduction to the error-statistical approach with a final section on the title. Philip Mirowski’s “The Unreasonable Efficacy of Mathematics in Economics” is a reconsideration of most Mirowskian themes (physics’ envy, computers and markets, etc.) from a new angle (what sort of philosophical approach to mathematics would do justice to its uses in economics). Some of these veterans present instead research conducted after the publication of that first Handbook: for example, John Davis on individuals in economics or Marcel Boumans on measurement.
There are topics in the 2012 volume that have grown beyond anyone’s expectations fifteen years ago. Alan Nelson’s 1998 entry on “Experimental economics” called for further methodological reflections on internal and external validity, now accomplished in Francesco Guala’s piece for the 2012 volume, drawing on a decade of his own work. Herbert Simon claimed in 1998 that “behavioural economics is not so much a specific body of economic theory as a critique of neoclassical economic theory and methodology”. But Erik Angner and George Loewenstein present it in their 2012 paper as a “bona fide subdiscipline of economics”. I could not find in the 1998 index a mention of the ultimatum game, for which there is a paper in 2012 by Cristina Bicchieri and Jiji Zhang (about the incorporation of norms of justice into decision models). Dan Hausman writes about the experimental testing of game theory, another virtually absent topic in the 1998 handbook. Summing up, the papers explicitly addressing experiments claim 133 of the 903 pages of the 2012 volume, whereas they barely add to 10 of the 572 pages in the previous installment.
Other topics have not changed so dramatically. Apart from experiments, it seems as if nothing is radically different in the philosophy of game theory (T. Grüne-Yanoff and A. Letihnen) and rational choice theory (P. Anand). The methodological debate on disciplines such as evolutionary economics, feminist economics and public choice is mostly the same if we judge it from the content of the papers by, respectively, Jack Vromen, Kristina Rolin and Hartmut Kliemt. The piece on the economics of science was programmatic in 1998, whereas now Jesús Zamora Bonilla provides a survey of actual contributions. Most results in judgment aggregation date from this last decade so the short (and helpful) introduction written by Christian List is a real novelty in this volume. Geographical economics is also a new topic, but not because the discipline is new but rather thanks to a philosopher (Caterina Marchionni) who has decided to tackle its methodology.
At this point, the reader might be wondering what has been left behind in economic methodology. The most significant loss is the history of economic thought: organized in short dictionary-like entries, in the 1998 volume there were many about particular economists; but in 2012 only Mirowski adopts a full-fledged historical approach. Is this is a sign of how the profession is evolving? Whereas many of the senior contributors had a separate career as historians (Backhouse, Hands, Hoover, Morgan, etc.), this is less common among their junior peers (Angner is probably the most significant exception). However, there is an increasing (but still far from consensual) advocacy for an integration of History and Philosophy of science among practitioners of this latest discipline (e.g., Hasok Chang). Given how prominent this integration has been during decades in the case of economics, I think a more explicit reflection on the virtues (or flaws) of doing philosophy in such close connection with history could have been useful.
The second, but minor, loss is Marxism. In the 1998 Index it was explicitly mentioned in about 30 pages. In 2012 it is just mentioned five times, all in the same paper. In it we find, I think, the more original contribution to this volume, as compared to its predecessor. Don Ross’ “Economic Theory, Anti-economics and Political Ideology”, classifies five principled objections against economics as a purely positive endeavor and proceeds to refute them. Ross argues that economists defending the efficiency of markets are not promoting partisan views, if their arguments are read literally or, if they do, they are not representative of the profession. “The economic attitude –he claims– is consistent with policies drawn from anywhere on the left-right spectrum that acknowledges scarcity as fundamental to political and social organization” (p. 280). Ross’ strategy is to subvert the popular understanding of economic theories drawing on a combination of conceptual analysis and historical acumen (an integrated HPS, after all?). The reader will find another take on the same approach in his other paper in this compilation, “The economic agent: Not Human, But Important”, where he defends his well-known thesis that economic agency reliably captures bug-like decision making, but still is useful to understand ours. In other words, economics is a perfectly positive science, provided you have the proper concept of what economics and science are. I was unable to find anyone so bold about it in the 1998 volume.
It is significant that both Don Ross and Harold Kincaid have two papers each in this volume (unlike every other contributor), totaling 130 pages. In a decade of joint work, they have renewed our understanding of the philosophy of the social sciences putting forward a variety of naturalism that combines their own versions of contextualism (Kincaid) and structural realism (Ross). Following the path of Uskali Mäki, Alex Rosenberg or Dan Hausman in the 1990s, they have addressed economics in connection with broader problems in philosophy of science –in this respect, I guess it would have been fair to include a chapter by/about Nancy Cartwright’s views, the other great contender in this league. This is probably the take home lesson of this volume for newcomers in the discipline: stay close to actual practice (e.g, experiments) and make your philosophical position as general as possible (as Kincaid and Ross have done).
But speaking of newcomers, I should say something about the audience of this volume. Namely, that I do not see very clearly who their readers are. Its size and price (165 EUR) make it clearly a reference work for libraries, but not every paper is suitable for just the curious reader or first year student: all of them are very good, but some are very long, some are narrow in their approach (or very personal) and few suggest the reader where to go next. In addition, I think that, as an intellectual community, we are about to exhaust the Handbook genre for pure lack of diversity (and I plead myself guilty since I have contributed to three similar volumes in the last five years). Ross and Kincaid have their fair share of Mäki’s compilation, but they have edited themselves two other Handbooks for Oxford, where they extensively present their views (and so do Mäki, Vromen, Guala and a few other authors of this volume). I also read Ross, Guala and Knuuttila in another Handbook co-edited by Zamora Bonilla for Sage. This is probably the Matthew effect, but I wonder if our university libraries will really benefit from acquiring all these collections every ten years. Perhaps we should invest more in new editorial formats (like the Stanford Encyclopedia of Philosophy) that perform more or less the same function in a more updated and accessible way. de
{December  2012}
{Journal of Economic Methodology, 21.1 (2014)  96-98 }

26/12/12


Peter Stone, The Luck of the Draw: The Role of Lotteries in Decision Making, Oxford University Press, 2011, 195pp., $49.95 (hbk), ISBN 9780199756100

Almost everybody is familiar with one or two instances of the use of lotteries for public decision-making: allocating immigration quotas or filling juries are, perhaps, among the most popular today, but it is indeed a very old practice that has been documented in Greece, Israel, and other ancient cultures. In other words, it is a deeply rooted tradition in Western politics and yet, until very recently, there has been no systematic account of its normative foundations and applications. The Luck of the Draw is one of very few attempts at finding some conceptual unity in the political use of lotteries. Peter Stone considers here the two main types of decision by lot: the allocation of scarce goods and the assignment of public offices. His take is clearly normative, despite the wealth of evidence on lotteries discussed in the book. Stone investigates when lotteries are desirable, in particular when they are fair.

Stone’s case for lotteries hinges on the conceptual systematization and clarification of what lotteries are and when it is fair to use them. This is achieved through two normative statements, the lottery principle and the just lottery rule. First, Stone contends that there is an encompassing rationale for every use of randomization in decision-making processes, what he calls the lottery principle. According to this principle (p. 37), we would be justified in requesting that a decision is made by lot if it prevents the decision maker from influencing the outcome on the basis of reasons. This is “the sanitizing effect” of lotteries: they screen off some reasons from the decision process, be they good or bad, because the outcome of the decision becomes unpredictable for the decision-maker. But, of course, lotteries seem only defensible in cases where bad reasons may affect decisions, either because there are no good ones or, if there are, we cannot filter the bad ones out. 

Stone analyses then under which circumstances we would be normatively justified in using lotteries in the allocation of goods. Again, there is a general justifying principle, the just lottery rule (p. 53): “under conditions of indeterminacy, if an agent must allocate a scarce homogeneous lumpy good amongst a group of parties with homogeneous claims, then the agent must do so using a fair lottery”. In other words, if there is a suitable division of a good which all parties are equally entitled to claim, but there is not enough of it for everybody, a fair lottery is the most impartial tie-breaker: it only takes into account the equal strength of the claims over it (p. 78). This is guaranteed by the sanitizing effect of the lottery principle, since in a random allocation every other reason (merit, desert, nepotism…) is simply left aside. If the lottery gives equal probability to equal rights over the good, the allocation procedure will be fair. According to Stone, the just lottery rule is grounded on Scanlon’s contractarian approach: in cases of indeterminacy, every other alternative allocation rule (be the outcome certain or uncertain, as in weighted lottery) will be reasonably rejected by the involved parties.

Apart from systematizing and clarifying the concept of a fair lottery for the allocation of scarce goods, Stone’s case rests on a critical examination of other normative approaches to lotteries and alternative allocation rules. As to the former, Stone takes issue with justifications of lotteries in terms of consent (Goodwin), equality of opportunities and equality of expectations (Kornhauser and Sager), as well as with alternative contractarian foundations (namely, Rawls and Harsanyi). Stone considers as well eight alternative allocation procedures (e.g., desert, queuing, etc). The discussion is often quick, but insightful too. 

Finally, Stone adds a chapter on the assignment of public responsibilities by lot (usually known as sortition). The author contends that there is no unifying principle to justify its many uses documented throughout history. Stone discusses instead three kinds of arguments for sortition: allocative justice –rehearsing the previous arguments–, incentive alignment and descriptive representation. The former exploits the capacity of randomization to screen off perverse motivations in politics, e.g., nepotism in the appointment of public officials. The latter draws on the virtues of lotteries to make assemblies representative in a statistical (descriptive) sense: a random draw in a population with certain relevant characteristics can provide a sample that faithfully represents the distribution of such characteristics in the whole. But, of course, in both cases there is a clear trade-off between the virtues of lotteries and their various side-effects (e.g., the exclusion of qualified candidates), so Stone does not consider any of these arguments conclusive. The Luck of the Draw ends with a long concluding chapter addressing nine loose ends. 

Even if the reader disagrees with Stone’s arguments, it must be granted that the two principles provide an excellent thread to organize a compact overview of political lotteries. In my view, the author is right in adopting impartiality as the key to his normative analysis: it is open to debate whether lotteries yield (e.g.) equality of opportunity, but there is a clear consensus on the role of randomization as a warrant of impartiality even in purely epistemic contexts: we want a randomized allocation of treatments to patients in a clinical trial, for example, to prevent physicians from giving one particular drug to the patients they feel would benefit more. Humanitarian as this may be, it would spoil a fair comparison between treatments. However, Stone argues as if the normative leverage of lotteries stems from the exclusion of reasons alone: in allocating scarce goods, it would not be reasonable to oppose a fair lottery, where reasons play no role. But the superiority of such lotteries (compared to other allocation methods) lays in that they do not just sanitize reasons, but conscious and unconscious biases of all sorts. Psychologists have documented at length how people acting with the best reasons unwittingly deviate from them in a systematic fashion: a physician allocating treatments may be sincerely convinced that he treated all patients the same; but the data often reveal otherwise. This is the impartiality bias: we tend to think that we are more neutral than we actually are. Hence, for purely strategic considerations, I will request a randomized procedure if, for whatever reason, I suspect that the allocation of a scarce good may be otherwise biased (e.g., Kadane & Berry 1997), even if the people in charge of the allocation were guided by the best reasons alone. An interest-based contractarianism may provide in this respect a broader foundation for the impartiality of lotteries than Scanlonian reasonability. But biases and interests are simply left aside in The Luck of the Draw.

Stone does a wonderful job in unifying the discussion of scarce good lotteries under the umbrella of impartiality. But fair lotteries as allocation mechanisms are often uncontroversial: whatever the reasons we have to accept them, there is experimental evidence showing that we tend to like them (e.g., Bolton et al. 2005). I would have liked to see a more thorough discussion of the limitations of impartiality in the justification of sortition. According to Stone, we would need a general account of political decision-making (p. 123) if we were to construct all-encompassing rules of justice for sortition. But my impression, at least, is that the justice of lotteries depends implicitly of the type of good we are drawing lots for. When treatments are randomized in a clinical trial, the resulting allocation is often corrected because it doesn’t look random enough (e.g., one treatment goes to men and the other one to women). Whatever we do, there is a potential source of bias in such cases: maybe the unbalanced allocation is in itself biased, but if we grant us an unrestricted right to correct it, we may end up biasing it anyway. Whereas in scarce good lotteries only a few allocations may seem unbalanced, the outcomes of sortition are much more open to controversy: as the randomized selection of criminal and civil juries in the United States shows, for instance, there is an endless supply of motives for defense attorneys to strike jurors. The impartiality of the procedure in lotteries of this sort does not always provide a good enough reason to accept the outcome.

In sum, it would have been interesting to explore empirically what makes a lottery acceptable, addressing them as a procedure to control subjective biases and not only as the implementation of general criteria of justice. However, the exploration of this latter is enough to make The Luck of Draw an excellent read.


Berry, Scott M., and Joseph B. Kadane. 1997. Optimal bayesian randomization. Journal of the Royal Statistical Society. Series B (Methodological) 59: 813-819.
Bolton, Gary E., Jordi Brandts, and Axel Ockenfels. 2005 Fair procedures: evidence from games involving lotteries. The Economic Journal 115: 1054-1076.

{Agosto 2012}
{Economics and Philosophy 29.1 (2013), 139-142}