Probably the best‐​known current federal judge who is not a Supreme Court justice is Richard Posner, who has been a judge on the 7th Circuit since 1981. Posner is known for his judicial decisions, his crystal‐​clear writing style in those decisions, and his prodigious output: over 40 books and hundreds of articles in law reviews, economics journals, and popular publications.

Given his importance in both academia and the federal courts, we have been due for a book that tells us more about the man. In most of the important ways, William Domnarski’s Richard Posner is that book.

Domnarski, a lawyer himself, shows obvious respect for his subject, calling Posner “the Wayne Gretzky of appellate judges.” He spent three years researching his subject and interviewed over 200 people, including Posner. He studied Posner’s early history. He also read all of Posner’s thousands of decisions and much of his correspondence. As a result, we get a good idea about how Posner’s mind works and his various attitudes.

Domnarski details the judge’s thinking in dozens of his decisions, telling us Posner’s bottom line and, in many cases, how he reached his conclusions. For example, we get to see the strong role that economic analysis and broader social science play in his court decisions.

We see Posner call out various judges for intellectual laziness. He tangles with the late Supreme Court Justice and his former University of Chicago colleague, Antonin Scalia. He acerbically dresses down some police officers who have violated a defendant’s Miranda rights. He confidently reaches conclusions about public policy based on his largely self‐​taught economic understanding.

Unfortunately, we often don’t get to see how Posner reaches his conclusions. As an economist, I usually was able to fill in the blanks, but many readers will not. Filling in the missing arguments would probably have added 20% to the book’s length and so it’s understandable that Domnarski didn’t do so. In the age of the Internet, though, there’s an easy fix: put in links to a special website that details Posner’s reasoning.

Beyond advocacy / In the opening chapter, Domnarski describes Posner as a star student from an early age: in public school, then as an undergraduate literature major at Yale, and finally as a law student at Harvard. Posner then took some fairly important jobs in federal government agencies in the 1960s. Before reaching age 28, while at the Office of the Solicitor General under President Lyndon Johnson, he had argued six cases before the Supreme Court.

Posner, it turns out, “practiced his oral arguments to his cat.” However, Domnarski writes, those arguments “had as much influence on the Justices as they had on the cat.” Said Posner, “Whatever drove Supreme Court decisions, it wasn’t the lawyers’ advocacy.” That was one reason he left his job with the solicitor general.

But then he got lucky—if luck is the right word to apply to someone who works very hard, thinks for himself, and searches out interesting intellectuals. In 1968 he joined the Stanford Law School faculty and met Aaron Director and George Stigler. Director, the older brother of Milton Friedman’s wife, Rose, had moved to Stanford in 1965. While at the University of Chicago Law School, he had started the Journal of Law & Economics and was one of the founders of the field of law & economics.

While you won’t find Director’s name as an author of many important works, he is often in the acknowledgements as the person who came up with the idea that led to this or that path‐​breaking article. One early such article was John S. McGee’s “Predatory Pricing: The Case of Standard Oil of New Jersey.” In it, McGee found—as Director had suspected based on a priori economic reasoning—that Standard Oil had not engaged in predatory pricing.

Stigler, an economics professor at the University of Chicago, spent part of every winter at Stanford. (For some reason, Domnarski never mentions that both Director and Stigler worked at Stanford’s Hoover Institution.) Stigler was arguably the leading economist in industrial organization at the time. Posner used his time with Director and Stigler well, soaking up their insights. His conversations with them profoundly affected his career.

He moved to the University of Chicago Law School in 1969. There, he became thoroughly familiar with the law & economics literature and started making his own contributions. And those contributions didn’t take long. In 1971 he started the Journal of Legal Studies. By 1973 he had published his first magnum opus, Economic Analysis of Law. The book made a big splash at the time, earning many reviews, and established Posner as one of the leading scholars in law & economics.

In 1981, President Ronald Reagan appointed him to the 7th Circuit, based in Chicago. From then on, what made the biggest splashes were Posner’s opinions in many of his thousands of decisions. And his prominence and ability as a judge led to opportunities to write about policy issues, judicial and otherwise.

In 1988, for example, Chief Justice William Rehnquist appointed him and 14 other “judges, legislators, academics, and lawyers” to the Federal Courts Study Committee. The impetus for the committee was the congestion and delay in cases that federal courts were experiencing. Posner and Larry Kramer, future dean of Stanford’s Law School, wrote their subcommittee’s report. It included a number of recommendations such as, in Domnarksi’s words, “establishing a $10,000 minimum for federal tort claims” and repealing the Jones Act, which requires that all goods shipped between U.S. ports be carried on U.S.-built ships staffed with U.S. citizens and permanent residents.

Domnarski doesn’t explain why they made those recommendations. As an economist, I think I can fill in some of the reasoning. The purpose for the $10,000 minimum would presumably be to “not make a federal case,” to use an old expression, out of relatively small claims, thus freeing up valuable court time. The Jones Act is one of the laws that informed economists especially hate because it makes shipping very expensive. Foreign ships can’t deliver freight to two different U.S. ports in one voyage. Instead they must break bulk in one port and then use U.S. ships to take the cargo to the other port. The economic inefficiency is obvious.

When Domnarski does spell out Posner’s reasoning on various court cases, he generally does a good job. Take, for example, Vande Zande v. State of Wisconsin Department of Administration, a case under the Americans with Disabilities Act involving a paraplegic employee. The act requires an employer to “reasonably accommodate” employees with disabilities. Posner pointed out that reasonable care is not the same thing as maximum care. Drawing on negligence law, in which the issue of reasonableness arises, Posner wrote that “similar reasoning could be used to flesh out the meaning of the word ‘reasonable’ in the term ‘reasonable accommodations.’ ” If there were no limitations, Posner argued, employers could be faced with “potentially unlimited financial obligations to 43 million disabled persons.” This unlimited obligation would impose “an indirect tax potentially greater than the national debt.” Posner concluded that there was no basis in the law’s language or history for concluding that Congress’s intention was “to bring about such a radical result.”

Sharp critic, fawning worshipper / One pleasurable (to me) part of the book consists of portions of Posner’s letters to University of Chicago philosophy professor Martha Nussbaum. Apparently, after she had criticized “Chicago‐​style economics,” Posner wrote in response, “Your acquaintance with economics seems so distinctly second‐​hand.” After she had argued for rent control, he wrote, “Not to seem too impertinent, it seems to me that your views of rent control stem from ignorance of a large economic literature about it.” Indeed. In response to her claim that Americans feel inferior because they lack culture and are familiar only with economics, movies, and Wagner, Posner wrote, “Leave out economics and Wagner, and it’s still wrong. I don’t think you know what country and century you’re living in.”

One fact that surprised me—because I have not followed Posner closely—is that he is an “uncritical, fawning worshipper” (Posner’s own words) of Justice Oliver Wendell Holmes. Posner edited and wrote a long introduction to The Essential Holmes, a book of excerpts from Holmes’s decisions and letters. What did Posner think of Holmes’s majority opinion in the infamous Buck v. Bell case, which upheld the constitutionality of compulsory sterilization? On his assumption that Carrie Buck was “feeble‐​minded,” Holmes wrote his famous line, “Three generations of imbeciles are enough.” Although Posner loved the rhetoric, he did criticize “the reasoning and the result.”

He is a harsh critic of federal judges, arguing that many of them are lazy and that they should write their own decisions rather than have their clerks write them. Two famous judges whom he takes on are current Chief Justice John Roberts and the late Justice Antonin Scalia. In a 2012 article in Slate, after Scalia had dissented from parts of the majority opinion that invalidated some provisions of an Arizona law on immigration, Posner raked Scalia over the coals. Scalia had written, “[Arizona’s] citizens feel themselves under siege by large numbers of illegal immigrants who invade their property, strain their social services, and even place their lives in jeopardy.” Wrote Posner, “But the suggestion that illegal immigrants in Arizona are invading Americans’ property, straining their social services, and even placing their lives in jeopardy is sufficiently inflammatory to call for a citation to some reputable source of such hyperbole. Justice Scalia cites nothing to support it.” Aside from his question‐​begging use of “hyperbole”—if it were hyperbole, one would be hard put to find a “reputable source” to support it—Posner made a good point.

In my view, Posner was at his finest in his 2014 United States v. Slaight opinion reversing the conviction of Michael Slaight for receipt and possession of child pornography. The police had clearly denied Slaight his Miranda warning, and Posner saw through it. Dismissing the police argument that they wanted to interview Slaight at the police station rather than at his home because his windows were covered with trash bags, blocking the sunlight, he wrote sardonically that “the officers gave no reason why an interview, unlike painting a landscape, requires natural rather than artificial light.” As to their argument that the house “had a strong smell of cats,” Posner, who to his credit is pro‐​cat throughout the book, wrote that “police smell much worse things in the line of duty.” The final two sentences of his decision are terse and beautiful: “These facts are incontrovertible and show that the average person in Slaight’s position would have thought himself in custody. Any other conclusion would leave Miranda in tatters.”

Central planners / There is no mention in the book of any basic insights from public choice in Posner’s decisions or writings. Indeed, there is no evidence that he understands and applies such insights. At times he comes across as someone who has much more faith in government officials than seems justified. Whether it’s his advocacy of a domestic intelligence agency in Remaking Domestic Intelligence or his support of Keynesian economic policies in A Failure of Capitalism, Posner shows little inclination to think through some of the perverse incentives that government officials might have when carrying out the programs he advocates.

Posner has shown that he can attribute bad incentives to the police, but he doesn’t worry enough, in my view, about the incentives and motives of employees of intelligence or fiscal agencies, among others. In his mind, there is more than a little belief in the benevolence—and competence—of central planners. Still, Domnarski’s book reminds me that I’m glad that Richard Posner is in this world.