The Becker-Posner Blog

Posner on Privacy

Recent controversy over the digitizing of medical records has brought to the fore the issue of balancing privacy against other values. Digitizing medical records would help doctors and patients by making it much easier, swifter, and cheaper to transfer these records when a patient switches doctors or is treated by a new doctor in an emergency or needs to consult a specialist. But once records are digitized rather than existing solely in hard copies in the office of the patient�s primary physician, the risk that unauthorized persons will gain access to them is increased. So, as often in law and public policy, a balancing of imponderables is required. My own view is that we tend to place somewhat too much weight on privacy. The word �privacy� has strongly positive connotations (like �freedom�), which obscures analysis. All that privacy means in the information context (for I am not talking about the Supreme Court�s usage of �right of privacy� to describe the right to an abortion and other sex-related rights�the Court appropriated the word �privacy� to describe these rights presumably because of its positive connotations) is that people want to control what is known about them by other people. They want to conceal facts about themselves that are embarrassing or discreditable. The two motives should be distinguished. In many cultures, including our own, there is a nudity taboo (oddly, it is much weaker in northern European nations); except for commercial purposes (prostitution, striptease, pornography, etc.), and the tiny band of nudists, people are embarrassed to be seen naked by strangers. Why this is so is unclear; but it is a brute fact about the preferences of most people in our society, and since transaction costs are low, it makes sense to assign the property right, in this instance at least, to the individual whose privacy is sought to be invaded. There is no dearth of persons willing to sell the right to see them performing or otherwise appearing in the nude, so there is a well-functioning market without need to coerce anyone to so appear. The second motive for privacy, however�the desire to conceal discreditable facts�is more questionable from a social standpoint. In order to make advantageous transactions, both personal (such as dating or marriage or being named in a relative�s will) and commercial, people try to �put their best foot forward.� Often this involves concealing information that would cause potential transacting partners to refuse to transact with them or to demand better terms as a condition of doing so. Such concealment is a species of fraud. It is too prevalent and, on the whole, insufficiently harmful to require legal sanctions (other than in exceptional cases). In addition the potential, victims of such fraud can usually protect themselves (though not costlessly): for example, lengthy courtships are a way in which potential spouses verify the implicit and explicit representations of each other and thus unmask the frauds that are a common feature of romantic entanglements. Moreover, to require blanket disclosure of private facts, thus treating every individual as if he were the issuer of a securities prospectus regulated by the SEC, would drown society in trivial and distracting information. It does not follow that the law should go out of its way, as it were, to enable, to protect, these (minor) frauds by granting expansive legally enforceable rights of information privacy. Medical records are a case in point. People conceal their medical conditions (sometimes as a means of concealing behaviors that have led to medical conditions), in order to obtain insurance at favorable rates, obtain and retain jobs, obtain spouses, becomes President (in the case of John F. Kennedy, who concealed his long array of serious illnesses), and so forth. These concealments can impose significant costs on the other parties to the transactions. This is not to say that all such concealments are strategic. I believe that many people would be uncomfortable to learn that their medical history had been disclosed to people living in distant countries, people with whom the possessor of the medical history will never transact. This would be like the nudity taboo: concealment motivated by embarrassment rather than by transactional objectives. I mentioned that in exceptional cases in which people try to keep information about themselves private the law does step in. No one wants privacy more than criminals! Yet searches, wiretapping, and other means of surveillance are authorized to invade the �privacy� of criminals, terrorists, and other antisocial persons. Because of its favorable connotations, the word �privacy� is rarely used in such contexts. It would be good if the word was either purged of those connotations, or, more realistically, was understood, in disputes over measures such as digitizing medical records that compromise �privacy,� that was what stake was simply reducing somewhat the ability of people to manipulate other people�s opinion of them by selective disclosure and concealment of information. Even strategic secrecy, however, can have positive social value. An example is trade secrecy, which is a method of obtaining protection against copying that would prevent appropriating the benefits of an innovation. In addition, some, perhaps a high, degree of privacy of communications is socially beneficial (hence wiretapping and other forms of eavesdropping are lawful only when directed against criminal and other public enemies, actual or suspected), because people will not speak freely if they think they are being overheard by strangers, and there is value in frank communications, including being able to try out ideas without immediate exposure to criticism. The particular concern I have with defenders of privacy arises when they argue for legal rights to blanket concealment not of communications, and not of embarrassing facts, but of facts that would be material to the willingness of other persons to transact with the concealer on terms favorable to him.

Comment on Privacy-BECKER

As Posner indicates, the meaning of �privacy�, like many other loose terms, becomes less clear on close examination. Yet basically, privacy issues come down to who controls certain information � in economic language, to who owns the �property right� to knowledge about the circumstances, attitudes, or behavior of individuals. I believe property rights to information should belong to individuals who are most affected, which in most situations are the persons referred to by the information. The exceptions essentially are situations where the harm to others from their not having this knowledge is too great to deny them access. These principles become clearer through examples. Take the case of medical records raised by Posner. I do believe it is important to digitalize medical records, so that they can be collated and organized to improve treatment of various diseases. I am involved in an organization that, among other things, is encouraging this digitalization process in order to speed up progress in treating serious diseases. Nevertheless, in the vast majority of cases, individuals should have the residual rights over information about their medical conditions and treatments since they have the greatest interest in seeing that this information is used appropriately rather than abused. This does not require a cumbersome procedure, and helps protect individuals against unauthorized and possibly ill-advised uses. Of course, if they choose, individuals can share their medical records with various hospitals and physicians, and allow them to be used for different purposes. Participate in clinical trials are asked to sign waivers that allow their treatment and response to be used by persons analyzing the trial data, although names of participants are usually kept private. Another example involves letters of recommendation for students as they apply for graduate work, jobs, or financial support. The present rule gives students the residual right to see these letters, but also allows them to give up this right through written consent. I have written hundreds of recommendations, but I do not write any unless persons seeking recommendations forfeit their right to see what I have written. I want to protect my own privacy! However, I have no problem with the requirement that anyone asking for a recommendation must have conceded in writing their right to see a recommendation before they are prevented from doing so. All principles have exceptions, and so does the assignment of property right to protect privacy. Fortunately, the exceptions are easy to justify in most cases. As Posner indicates, a criminal is forced to concede his right to privacy against wiretapping, searches, and other means of surveillance. A repeated sexual offender may lose the right to prevent that information from being made public. The rationale is that the potential harm to society from concealing information about past or potentially future criminal behavior greatly exceeds the gain to criminals from protecting their privacy. Still, it should be difficult for governments and private parties to obtain the right to various kinds of surveillance, such as wiretapping, in order to prevent its abuse against political opponents, business rivals, or for blackmail. Persons with highly contagious serious diseases often lose the right to protect that information since the social gain from public knowledge of their illness may be very large. Many societies have rightfully quarantined persons with diphtheria, scarlet fever, smallpox, and other highly contagious diseases. A harder case is information about persons who are HIV positive since that disease is not yet curable, but HIV positive persons pose major threats to anyone who has sexual relations or share needles with them. I believe the social gain from publicizing that information outweighs the right to privacy, although that position is arguable because individuals might then delay seeking treatment and discovering whether they are positive. To summarize, I believe we should usually give individuals the benefit of the doubt, and protect their right to privacy about knowledge concerning their health, behavior, etc without inquiring into the motives behind their desire for privacy. This protects them from its use in ways that have little social value, and yet would cause considerable embarrassment or discomfort. But like other property rights, individuals are free to allow others to have access to their private information. And clearly, sometimes the social value of this knowledge is too great to allow it to be kept private. But the obstacles to using information about anyone without their consent should not be easy to overcome.

Nuclear Power--Posner's Response to Comments

There were a number of good comments, as usual. Let me first correct a mistake. I said that "reprocessing [spent nuclear fuel] produces as a byproduct plutonium, which is readily convertible to nuclear bomb material." The second part of the sentence is correct, but not the first. The spent fuel from the operation of the ordinary nuclear reactor contains plutonium; that is why on-site storage is so problematic from the standpoint of terrorist threats: plutonium is present wherever spent fuel is stored. The plutonium in spent fuel can be recycled into a fuel for nuclear reactors, and this might seem the solution to the disposal problem, but there are special safety concerns and the reprocessing itself produces considerable radioactive material as a byproduct. For a compact description, see pages 106-108 of the MIT nuclear-power study that I cited in my original posting. I should also have mentioned that while creating a nuclear waste dump in lieu of on-site storage would alleviate the problem of stealable plutonium stored on site, it would not solve it. And this for two reasons: plutonium would remain stored on site awaiting shipment to the dump; and trucks carrying the plutonium to the dump are potentially vulnerable to being attacked. Notice also that the more frequent the shipments, the smaller the amount of plutonium that will remain stored on site but the more potential interceptions of the traffic between site and dump there will be. A further point to add to my original discussion is that if greater use of nuclear power resulted in a fall in the demand for oil, this would have the incidental effect of reducing the price of oil. The cost of producing oil varies. As demand grows, higher-cost producers are drawn into the market, and their costs determine the market price. If demand falls, therefore, the highest-cost production will be withdrawn and price will fall. This is true even when the producers collude (the OPEC cartel); other things being equal, when cost falls the optimum monopoly or cartel price also falls, though it remains above the competitive level. But the effect of a gradual, incremental increase in nuclear power generation on the demand for oil would be modest. And a more important policy goal than reducing the price of oil is reducing our dependence on foreign, especially Middle Eastern, oil. This could be done by a heavy tax on oil, which would reduce the demand for oil much more than a modest increase in nuclear electrical generation would do. One comment points out that if current unlike older reactor designs are quite safe against the risk of an accidental (as distinct from terrorist-induced) meltdown, this provides an additional reason for building new reactors: replacement of older, dangerous ones. Most of the comments on my posting, oddly enough, debate global warming, which I had mentioned only in passing. I have discussed the issue at length in my book Catastrophe: Risk and Response (2004), and do not wish to repeat the discussion here. Suffice it to say that while there are skeptics, there is also a strong scientific consensus that global warming is an increasingly serious problem to which human activities, mainly the burning of fossil fuels and the clearing of forests by fire, both being activities that emit substantial quantities of carbon dioxide, a major "greenhouse gas" and one that indirectly increases another greenhouse gas--water vapor in the atmosphere--are contributing significantly. The point to emphasize in relation to the nuclear-power issue, however, is that the contribution of expanded use of nuclear power to generate electricity to alleviating the global-warming problem would be small because nuclear power at present generates only about 20 percent of the world's electricity and expansion of nuclear power would be gradual and of course would not affect the contribution to global warming of other activities besides the generation of electricity, such as automobile traffic. Moreover, because the effect of emissions of carbon dioxide on the atmospheric concentration of carbon dioxide is cumulative except in the very long run, merely reducing somewhat the current rate of emissions would not reduce, but would merely slow the rate of growth of, atmospheric concentration of carbon dioxide.

Reply on Nuclear Power-BECKER

Excellent discussion, and I learned a lot. A few comments. I probably dismissed the safety concerns about radiation leakage at the Yucca site too readily, but political opposition from Nevada politicians still seems to be the crucial factor holding it up. Nuclear reactors are getting safer, and newer ones have much smaller risks of meltdown. This seems to me to be an important reason for the United States to continue to build nuclear plants. This would speed up the rate of innovation, which would not only improve American safety, but also that in less developed countries as well since they would have access to safer reactors. I do not tend to support the President�s proposal for the government to assume liability of the risks from nuclear reactors-that would create too much of a moral hazard. However, I do believe it makes sense to sharply cap damages, especially punitive damages, from the harm caused by reactors. I advocated this type of cap more generally in an earlier entry on this blog. Even though the United States does not reuse its nuclear waste, a growing number of nations with nuclear weapons evidently are able to get enough plutonium. To me, this weakens the case for the ban on reusing this waste in American plants. The widespread exaggeration of the �normal� risks of nuclear energy has not stopped the United States from relying on nuclear powered submarines and stockpiling of huge quantities of nuclear weapons, nor has it prevented many other equally democratic nations, such as Sweden and France, from making far greater use of nuclear power to generate electricity. Perhaps this fear can be significantly reduced through greater education about its safety, evidence showing this greater use in some other democracies, and the significant role of nuclear power already in the United States.

Nuclear Power: Has its Time Come (Again)?-BECKER

Ever since the meltdown at Three Mile Island in 1979, no new nuclear plants have been licensed by the United States. However, it is now recognized that the safety measures at this plant worked, so that only a very small amount of radiation was released into the atmosphere, and this had no apparent harmful effects on health. The excellent safety record at American nuclear plants, growing imports of oil, natural gas, and other fossil fuels at high prices, and increased concern over the pollution and global warming caused by fossil fuels, has convinced me that the case for licensing new American nuclear power plants is compelling. Even though no American nuclear plants have been started for 25 years, old plants have raised their output much closer to their capacity. As a result, nuclear power currently supplies about 20 per cent of all the electricity generated in the United States. Yet this pales beside the situation in France, where nuclear power supplies more than 70 per cent of their electricity. As operating and construction costs of nuclear power plants have come down greatly since 1980, these plants have become competitive in costs with plants fueled by oil or natural gas, even at prices for these fuels of five years ago. If their presently high prices continue, nuclear power would be cheaper even than coal-fired power plants. In addition, several countries are building nuclear plants with new technologies, such as pebble-bed reactors that use helium rather than water to cool nuclear fuels. They appear to be much cheaper, and safer. In any case, the market place, along with due allowance for pollution effects and safety concerns, should be allowed to determine whether nuclear power is competitive with other methods of generating electricity. In fact, many countries have already decided in favor of nuclear power. China plans to add 20 or so new nuclear plants during the next 15 years, as it tries to curb its imports of oil and natural gas, and its use of coal. India, Japan, and South Africa are two of many other nations that are moving toward greater reliance on nuclear power. Nuclear power has several other advantages over plants powered by fossil fuels. Uranium is abundant, easily transported, and efficient in producing energy. One kilogram of natural uranium will yield about 20,000 times as much energy as the same quantity of coal. Nuclear plants would reduce American dependence on imports of natural gas and oil. To the extent there is concern about running out of fossil fuels- a concern that I believe is greatly exaggerated- nuclear generation of electricity becomes even more attractive. Whereas coal, oil, and even natural gas power plants emit substantial quantities of CO2, sulphur dioxide, nitrogen oxides, and other pollutants per megawatt of electricity generated, nuclear power plants release negligible levels of harmful pollutants. Growing concern about pollution helps propel the expanding interest in nuclear power. The advantage of nuclear power has become more concrete as a result of the Kyoto Agreement that requires signatories to cut back substantially on their emissions of CO2. The EU and Japan are already enforcing such cutbacks, and the United States is under continual pressure also to reduce CO2 emissions, even though it did not sign this Agreement. The case against nuclear power plants is mainly based on three considerations. Fear of a serious nuclear accident, even worse than at Chernobyl, the risks in disposing and storing radioactive nuclear waste, and terrorist attacks on nuclear plants that might release large amounts of radioactive materials. The chances of a serious accident at an American-approved nuclear plant is extremely low, given modern safety methods that are much better than even those at Three Mile Island, and new types of reactors that are safer still. The safety record is outstanding: there have been a few accidents at nuclear plants, but none have been yet implicated in many deaths or injuries in the United States, or in France, Japan, Scandinavia, and other developed nations that rely more extensively than America does on nuclear power to generate electricity. I am much more worried about safety at nuclear power plants in less developed and non-democratic nations. The second issue is the disposal of used fuel or waste from reactors since that waste is extremely radioactive. The options are either storage or reuse. The United States relies entirely on storage, and imposes a tax on nuclear power producers to pay for the storage of nuclear waste. The Department of Energy has concluded that a facility could be built in the Yucca Mountains of Nevada that would be both safe and large enough to house an immense quantity of nuclear waste. Politics, not safety, is holding up the construction of this and equally safe alternatives. France and some other nations recycle and reuse nuclear waste, so they do not have important waste storage problems. Given the general emphasis on recycling other wastes, it is surprising that America forbids recycling of nuclear waste. The answer seems to be that the United States has shied away from recycling because it produces plutonium, the ingredient for nuclear bombs. That seems less important now with the proliferation of nations with nuclear weapons. The newest concern about nuclear power plants stems from the sharp growth in terrorist attacks, especially the 9/11 attack. This is an important development, but it is being met partly through greatly beefed-up security at American plants with additional guards, traffic barriers, and other security protections. Some studies indicate that the enormous safety protections within American nuclear plants makes it very unlikely that bombs set off near these plants, airplanes crashing into them, or other terrorist activities would cause significant radiation leaks. Terrorist attacks on nuclear power plants that would release sizeable amounts of radiation are much more likely in less developed and less democratic nations that have looser safety standards than at American plants. The risk of a serious radiation leak from one of these sources is not zero, but such risks have to be balanced against geopolitical concerns and risks to the environment from relying on fossil fuels to generate electricity. My weighing of these considerations leads me to conclude that the time has come for America to follow the example set by Europe, Japan, China, and increasing numbers of other nations, and remove its ban on building additional nuclear power plants.

Nuclear Power�Posner Comment

If externalities are excluded, but fossil-fuel prices are assumed to remain high, nuclear generation of electricity is only marginally economical. (For helpful background, see The Future of Nuclear Power: An Interdisciplinary MIT Study [2003].) The question whether to permit or encourage the construction of additional nuclear electrical generating plants therefore turns on the weight given the various externalities that such plants produce, both positive and negative. On the positive side, emphasized by Becker, nuclear power is �clean�; unlike electrical generating plants that run on fossil fuels (coal, oil, or natural gas), nuclear plants do not produce any carbon dioxide or other greenhouse gas and therefore do not contribute to global warming. In contrast, electrical plants powered by fossil fuels are significant contributors to the atmospheric concentration of carbon dioxide and thus to global warming. However, even a marked expansion in the share of electricity produced by nuclear plants (currently about 20 percent of the world�s total) would have only a slight effect on global warming; for it would probably be decades before nuclear power substituted for fossil-fuel-burning plants on a large scale, and in any event reducing emissions of carbon dioxide merely slows�it does not reverse�the growth in atmospheric concentration of carbon dioxide, because the effect of emissions on that concentration is cumulative (except in the very long run): they would have to be reduced to zero, or even below zero, for the growth in atmospheric concentration to cease. A second positive externality, also stressed by Becker, relates to our dependence on foreign oil (and natural gas), a dependence that would be somewhat lessened by substituting nuclear fuel for fossil fuels in the generation of electricity. Of course dependence on foreign countries for essential inputs is not problematic in itself; it is a condition of international trade. But there is concern that our dependence on oil supplied by countries that are unstable, potentially hostile to the United States, or susceptible to intimidation by terrorists ties our hands in dealing with such countries. This is a legitimate concern, but will not be significantly alleviated by building a few more nuclear power plants. On the negative side, the traditional concern about nuclear power was the risk of a meltdown, such as occurred at Chernobyl. The danger created by nuclear plants built according to the latest designs is apparently quite trivial�provided that due care is used in construction, operation, and maintenance. That would not be a problem with nuclear plants built in the United States and other wealthy countries, but could be a serious problem with nuclear plants built in the Third World, perhaps including rapidly modernizing nations such as China, India, and Brazil. There are other negative externalities of nuclear power generation, however. One relates to the disposal of the spent nuclear fuel. There are two methods of disposal. The one used in the United States is storage. Because of local objections to nuclear waste, spent nuclear fuel is currently stored at the site of the nuclear plant itself. This is worrisome partly because of limited on-site storage space but more so because the danger of theft by terrorists is greater the greater the dispersion of the material. Many other countries avoid the storage problem by reprocessing the spent nuclear fuel. But reprocessing produces as a byproduct plutonium, which is readily convertible to nuclear bomb material. So the problem of disposal assumes truly serious form because of the threat of terrorism, and of proliferation of nuclear weaponry more broadly. Al Qaeda is known to have expressed interest in acquiring nuclear bombs; and the �dirty bomb� (a conventional explosive coated with radioactive material) seems an especially attractive terrorist device. The more nuclear power plants there are, the more weaponizable nuclear material there is, and so the greater is the threat of nuclear terrorism and proliferation. How much greater is difficult, probably impossible, to say. The negative externalities of nuclear power plants built only in the United States and other wealthy countries are small (with a qualification noted below), for these countries have the resources and the political will and capacity to secure nuclear power generation against both accidents and attacks. But if the U.S. were to commit itself to expanding its own nuclear generating capacity, it would be difficult to limit such expansion in Third World countries, where safety, terrorism, and proliferation risks are all much greater. Notice also that if only the U.S. expanded its nuclear power production, the impact on global warming would be even slighter than I have assumed. But I have ignored a factor that seems particularly significant in the United States. Distinct from the �real� negative externalities of nuclear power is the widespread exaggeration of what might be called the �normal� hazards of nuclear energy. The risk of a nuclear accident is one of those �dread� risks that people attach greater weight to than the actual expected cost created by the risk justifies. From an economic standpoint, however, stubborn fears, even when irrational, count as real costs, because they impose disutility; in any event, democratic politics give weight to public opinion whatever its rationality. The excessive fear of nuclear accidents seems related to the psychological association of nuclear energy with weaponry of unprecedented lethality and with to insidious operation of radioactivity (invisible, odorless, but deadly), producing monstrous offspring, etc. Americans� general ignorance of science is no doubt a factor in exaggerating what I am calling the normal risks of nuclear energy. I conclude that the case for actually subsidizing nuclear electrical generation has not been made. However, there is a stronger case for relaxing arbitrary regulatory barriers to the construction of new nuclear plants in the United States, provided that the widespread public fears of nuclear power can be overcome.

Posner's Response to Comments on His Plagiarism Posting

Many excellent comments, as usual. A number suggest that I am "soft" on plagiarism, especially when it is committed by professors and other "grown-up" writers, as distinct from students. I adhere to my heretical view that student plagiarism is a more serious offense. For one thing, the student who plagiarizes not only advances his career at the expense of his honest fellow students, but he doesn't learn a thing, whereas a professor who "steals" ideas or even phrases and incorporates them into his own work not only produces a better product to the benefit of his readership but may well improve his own skills. Itis one thing to copy blindly, another thing to use copied materials to create something new. Of course the author should acknowledge the copying; it is the failure to do so that is the wrong; my point is only that the plagiarizing work may have extra value by virtue of the plagiarism. Because faculty copying is more likely to be detected (the copy will be contained in a published work) and because exposure of a professor or other professional writer as a plagiarist is in itself a powerful shame sanction, and because as several comments point out computer search engines make detection of plagiarism ever easier, I continue to believe that the sanction of expulsion should probably be reserved for students. One commenter asked delicately whether Becker and I compose our blog "with external assistance." The answer is no, but the question underscores a particular concern that I expressed in my posting, and that is the fuzzy boundary of the concept of plagiarism. I do not think Becker and I would be guilty of plagiarism as currently understood if we used a research assistant to gather material for our blog. I am not even certain we would be thought guilty of plagiarism if we incorporated phrases or other material from a research memo prepared for us by a research assistant--I don't know enough about the conventions of blogging to have a view on this. (Clearly, however, if we lifted without acknowledgment material from another blog or some published work, we would be plagiarizing.) With novel media and novel expressive forms (such as the "managed book"), society needs new norms so that writers will know what they can and cannot do with or without acknowledgment. The conventions differ greatly across fields. I was reminded of this recently reading a very long law review article that contains a breathtaking array of citations to previous work. Nevertheless the author does not indicate which ideas in his article are original with him and which can be found in the literature that he cites. In fact many of his ideas are found in that literature. But I don't think he isguilty of plagiarism, because originality of ideas is not highly valued in law. Yet if he had copied actual passages (without acknowledgment) from a previous work, he would clearly have been guilty of plagiarism. Does this distinction make any sense? A little, I think, because one who copies ideas has at least to put them into his own words, and that requires some effort, whereas literal copying is effortless. But it is apparent that the meaning of plagiarism is highly field-bound and time-bound--that it is a culturally variable concept that requires careful mapping to avoid reckless accusations. One comment pointed out usefully that plagiarism can be a fraud on the public in a sense distinct from any I discussed--the comment gives the example of Margaret Truman, President Truman's daughter. A number of successful mystery novels were published under her name. Apparently none had been written by her--she had sold the use of her name to a pair of professional mystery writers. Finally, several commenters asked me how I use my law clerks, since I do write all my own opinions myself. I use the law clerks to study the cases before argument and give me their views as to how I should vote, what questions I should ask, etc.; to criticize my draft opinions and check them for accuracy; and, above all, to conduct research on the many factual and legal questions not adequately dealt with in the briefs of the parties or the other documents in the case. The contribution of the law clerks to my opinions is immense, though it does not include drafting; and likewise the contribution of my colleagues and, of course, of the lawyers and the lower-court judges. Consistent with the conventions of the judiciary, I do not acknowledge in my opinions the provenance of ideas contributed by colleagues, predecessors, law clerks, etc. Anyone seeking to evaluate a judge's creativity would do well to bear in mind the collective nature of the judicial product even when the judge does all his own writing.