Posts Tagged ‘inferential statistics’

The Law is Medieval

October 25, 2017

This post is based on an article by Oliver Roeder on the FiveThirtyEight website on 17 Oct 2017 titled “The Supreme Court is Allergic to Math.”

In 1897, before he took his seat on the Supreme Court, Oliver Wendell Holmes delivered a famous speech at Boston University, advocating for empiricism over traditionalism: “For the rational study of the law…the man of the future is the man of statistics and the master of economics. It is revolting to have no better reason for a rule of law than that so it was laid down in the time of Henry IV.” HM believes that if Oliver Wendel Holmes were alive today, he would also argue for an understanding of psychology and cognitive science. Much has been learned about how and why we humans perceive, think, and act. Unfortunately there is a poor fit between this knowledge and the law because the law is medieval.

The article notes that this problem was on full display this month, when the Supreme Court heard arguments in a case that will determine the future of partisan gerrymandering. The issue here is how to measure a map’s partisan bias and to create a standard for when a gerrymandered map infringes on voters’ rights. A proposed measure is called the efficiency gap. To calculate it, you take the difference between each party’s waster votes for winning candidates beyond what the candidate needed to win—and divide that by the total number of votes case. The aim here is to measure the extent of partisan gerrymandering. Now a threshold needs to be established for deciding when gerrymandering is agreed upon, and that is a reasonable basis for argument. And other metrics can be proposed for measuring gerrymandering. But the only intelligent way of assessing gerrymandering is through a statistic. But apparently, this is too much for some justices mental capacities. HM is asking himself why the term feebleminded was recalled while reading this. This is no esoteric statistical technique. And, indeed, statistical measures provide the only supportable means of addressing this problem. Chief Justice John Roberts dismissed attempts to quantify partisan gerrymandering: “It may be simply my educational background, but I can only describe i as sociological gobbledygook.” To be fair to Chief Justice Roberts, the fault may well lie in the educational system. Previous healthy memory blog posts have argued for teaching some basic statistics before graduating from high school. One cannot be a responsible citizen without some basic understanding of statistics, much less someone deciding questions on the Supreme Court.

Another instance of judicial innumeracy was the Supreme Court’s decision on a Fourth Amendment case about federal searches and seizures. In his opinion Justice Potter Stewart discussed how no data existed showing that people in states that had stricter rules regarding admission of evidence obtained in an unlawful search were less likely to be subjected to these searches. He wrote, “Since as a practical matter, it is never easy to prove a negative, it is hardly likely that conclusive factual data could ever be assembled.

But as the author’s article, Oliver Roeder, wrote “This, however, is silly. It conflates two meanings of the word “negative.” Philosophically, sure, it’s difficult to prove that something does not exist: No matter how prevalent gray elephants are, their number alone can’t prove the nonexistence of polka-dotted elephants. Arithmetically, though, scientists, social and otherwise, demonstrate negatives—as in a decrease, or a difference in rate—all the time. There’s nothing special about these kinds of negatives. Some drug tends to lower blood pressure. The average lottery player will lose money. A certain voting requirement depresses turnout.

Ryan Enos, a political scientist at Harvard, calls this the “negative effect fallacy. This is just one example of an empirical misunderstanding that has proliferated like a tsunami through decades of judges’ thinking, affecting cases concerning “free speech, voting rights, and campaign finance.

Some are suspicious that this allergy to statistical evidence is really a more of a screen—a convenient way to make a decision based on ideology while couching it in terms of practicality. Daniel Hemel, who teaches law at the University of Chicago said: [Roberts] is very smart and so are the judges who would be adjudicating partisan gerrymandering claims—I’m sure he and they could wrap their minds around the math. The ‘gobbledygook’ argument seems to be masking whatever his real objection might be.’

Reluctantly, one comes to the conclusion that there is no objective truth in the law. The corpus of law can be regarded as a gigantic projective test, analogous to the Rorschach Test. Judges can look into the law and see in it what they want to see. Rarely is a decision unanimous. And frequently decisions break down along the strict constructionist philosophy. But the Constitution should be viewed as a changing and growing document as democracy advances. Strict constructionists feel compelled to project themselves back in time and interpret the words literally as written. HM wonders why they would want to go back to a time when slavery existed, women could not vote, and blacks were counted as fraction of a human being. As long as time travel is involved, why not try to think of what they would have been written in light of today’s knowledge. After all, today’s high school science student knows more science than Benjamin Franklin did, who was the most distinguished scientist of his day. And the disciplines of psychology, cognitive science, and inferential statistics did not exist.

© Douglas Griffith and healthymemory.wordpress.com, 2017. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

Science Should Inform Democracy

April 23, 2017

The immediately preceding post, “Can Science Survive in a Democracy?”, focused primarily on the funding of science.  An equally, if not more, important issue is the use of science by a democracy.  Environmental and health issues are in the spotlight, but there is a wide variety of issues that can be usefully informed by science.  The failure to consider scientific evidence can have seriously adverse consequences.

One of the best examples of this failure is the size of the prison population in the United States.  The United States has 5% of the world’s population and 25% of its prisoners.  Remember that totalitarian governments imprison political dissidents, but the United States manages to surpass even these totalitarian countries on this grim statistic.  Moreover, this high rate of imprisonment did not address the problems they were supposed to solve.

The problems that were supposedly addressed were crime and drug abuse.  The public thought the best way to address these problems was by getting tough.  Politicians picked up this public sentiment and passed laws that were excessively severe for crime and proscribed drugs.  “Getting tough” might seem like a reasonable approach.  But it is a gut response, an emotional response that involves only System 1 processing according to Kahneman.  If thought processes had been engaged, System 2 processing in Kahneman’s terminology, the question would have been asked, does science have anything that would inform us as to what would be a reasonable policy?  If this question had been raised, the clear answer would have been that “getting tough” would be counterproductive, and it certainly was.

There are very few scientists or engineers, sometimes none, in Congress.  And few normal citizens read articles relevant to science.  As a consequence, they are unaware of their personal ignorance.  So what can be done to correct this widespread ignorance?

In the schools, science is taught primarily as an academic subject, and the subjects covered are typically biology, chemistry, and physics.  This is fine, but the relevance and applications of these sciences need to be taught.  The social sciences and statistics also need to be taught.  Every citizen needs to understand inferential statistics at some level to be a responsible citizen and to make reasonable decisions about personal health.  Unless college is going to be pursued, citizens can get by without understanding geometry or trigonometry.

It is essential that all students receive this education before graduating from high school, and not just students with plans for college.

Public television and a few dedicated cable channels have good programs on these topics, but they need to be increased, and they need to be presented on the major networks.

If done satisfactorily, constituents should inform their representatives as to the importance of these topics.  Then science would not only survive, but would prosper in this democracy.  And public policies would be informed by the best available scientific evidence.

© Douglas Griffith and healthymemory.wordpress.com, 2017. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.