Peremptory Challenges

During the jury selection process, attorneys may request that a potential juror be stricken for cause, e.g. the juror is related to the defendant. Attorneys also have a limited number of peremptory challenges, typically between 3 and 20 depending on the state and the seriousness of the charges, which are essentially accepted without question. In Batson v. Kentucky the Supreme Court ruled that peremptory challenges may not be based solely on race but it’s widely acknowledged that Batson has no teeth because attorneys can easily come up with pretexts–which need not rise to the level of causes–to strike.

Next month the Supreme Court will revisit peremptory challenges and race. I don’t have strong opinions on the issue, although a small number of peremptory challenges seem fine to me, if only to keep the system moving and reduce the time and resources spent on jury selection. One reason I don’t have strong opinions is that I don’t think peremptory challenges are as biased as a NYTimes article seems to suggests.The NYTimes article, for example, never mentions that defendants also get peremptory challenges!  A second more subtle reason is that diversity of the jury pool constrains the jury even when there are no minorities on the jury. Here, from an earlier post, I comment on the findings of The Impact of Jury Race in Criminal Trials:

What the authors discover is that all white juries are 16% more likely to convict black defendants than white defendants but the presence of just a single black person in the jury pool equalizes conviction rates by race. The effect is large and remarkably it occurs even when the black person is not picked for the jury. The latter may not seem possible but the authors develop an elegant model of voir dire that shows how using up a veto on a black member of the pool shifts the characteristics of remaining pool members from which the lawyers must pick; that is, a diverse jury pool can make for a more “ideologically” balanced jury even when the jury is not racially balanced.

Thus, diversity of the jury pool may be as important as diversity of the jury–in a way that’s fortunate since it’s easier to make the jury pool diverse (as we have done with required randomization) than the jury. Instead of eliminating peremptory challenges, I’d raise their cost. For example, suppose that both sides get 3 “free” peremptory challenges but if they wanted one more they would have to give two to the opposing side.

Addendum: Justice Kavanaugh has written in favor of restricting peremptory challenges.

RadicalXChange, March 22-24

Robert Wiblin of 80,000 hours has an excellent podcast with Glen Weyl on Radical institutional reforms that make capitalism & democracy work better. Weyl’s diagnosis of the problems of capitalism and democracy strike me as wrongheaded but on the other hand his solutions are interesting.and original. Wiblin does a good job of gently but decisively pushing back in places, e.g. in the discussion of high modernism.

RadicalXChange is hosting a big conference March 22-24 in Detroit. In addition to Weyl, speakers include Vitalik Buterin, Margaret Levi and Zooko Wilcox among others. I will be talking about open borders and also about city development on a panel with Devon Zuegel, Mwiya Musokotwane and Mark Lutter.

Corporate Law Before the FCA (or SEC)

In the late nineteenth century Britain had almost no mandatory shareholder protections, but had very developed financial markets. We argue that private contracting between shareholders and corporations meant that the absence of statutory protections was immaterial. Using approximately 500 articles of association from before 1900, we code the protections offered to shareholders in these private contracts. We find that firms voluntarily offered shareholders many of the protections that were subsequently included in statutory corporate law. We also find that companies offering better protection to shareholders had less concentrated ownership.

Acheson, Campbell and Turner writing in the Review of Financial Studies. Interesting implications for the US system of competitive federalism in corporate law.

Hat tip: Kevin Lewis.

Reducing Discrimination with More Information

From Cui, Li and Zhang:

We conduct four randomized field experiments among 1,801 hosts on Airbnb by creating fictitious guest accounts and sending accommodation requests to them. We find that requests from guests with African American-sounding names are 19.2 percentage points less likely to be accepted than those with white-sounding names. However, a positive review posted on a guest’s page significantly reduces discrimination: When guest accounts receive a positive review, the acceptance rates of guest accounts with white-sounding and African American-sounding names are statistically indistinguishable.

In other words, taste based discrimination is weak but statistical discrimination is common. Statistical discrimination happens when legitimate demands for trust are frustrated by too little information. Statistical discrimination is a second-best solution to a problem of trust that both owners/sellers/employers and renters/buyers/workers want to solve. Unfortunately, many people try to solve statistical discrimination problems as if they were problems of invidious prejudice.

If you think the problem is invidious prejudice, it’s natural to try to punish and prevent with penalties and bans. Information bans and penalties, however, often have negative and unintended consequences. Airbnb, for example, chose to hide guest photos until after the booking. But this doesn’t address the real demands of owners for trust. As a result, owners may start to discriminate based on other cues such as names. Instead market designers and regulators should approach issues of discrimination by looking for ways to increase mutually profitable exchanges. From this perspective, providing more information is often the better approach. As Cui, Li, and Zhang write in a HBR op-ed:

Our recommendation is for the platform companies to build a credible, easy-to-use online reputation and communication system. Bringing information to light, rather than trying to hide it from users, is more likely to be a successful approach to tackling discrimination in the sharing economy.

Addendum: See also Tyler and I in The End of Asymmetric Information. We need to work with information abundance rather than try to push against the tide.

Unicorns Found!

Dr. Jorge Pérez, an evolutionary biologist from the University of La Paz, and several companions, were exploring the Andes Mountains when they found a small valley, with no other animals or humans. Pérez noticed that the valley had what appeared to be a natural fountain, surrounded by two peaks of rock and silver snow.

Pérez and the others then ventured further into the valley. “By the time we reached the top of one peak, the water looked blue, with some crystals on top,” said Pérez.

Pérez and his friends were astonished to see the unicorn herd. These creatures could be seen from the air without having to move too much to see them – they were so close they could touch their horns.

While examining these bizarre creatures the scientists discovered that the creatures also spoke some fairly regular English. Pérez stated, “We can see, for example, that they have a common ‘language,’ something like a dialect or dialectic.”

Dr. Pérez believes that the unicorns may have originated in Argentina, where the animals were believed to be descendants of a lost race of people who lived there before the arrival of humans in those parts of South America.

While their origins are still unclear, some believe that perhaps the creatures were created when a human and a unicorn met each other in a time before human civilization. According to Pérez, “In South America, such incidents seem to be quite common.”

However, Pérez also pointed out that it is likely that the only way of knowing for sure if unicorns are indeed the descendants of a lost alien race is through DNA. “But they seem to be able to communicate in English quite well, which I believe is a sign of evolution, or at least a change in social organization,” said the scientist.

Click here for the rest of the story.

AIs Quickly Learn to Collude

AI’s are better than humans at Chess and Go, why shouldn’t they also be better at the game of collusion? Calvano, Calzolari, Denicolò and Pastorello show that they are (here quoting a VOXEU summary by the authors):

[In Calvano et al. 2018a] we construct AI pricing agents and let them interact repeatedly in controlled environments that reproduce economists’ canonical model of collusion, i.e. a repeated pricing game with simultaneous moves and full price flexibility. Our findings suggest that in this framework even relatively simple pricing algorithms systematically learn to play sophisticated collusive strategies. The strategies mete out punishments that are proportional to the extent of the deviations and are finite in duration, with a gradual return to the pre-deviation prices.

Figure 1 illustrates the punishment strategies that the algorithms autonomously learn to play. Starting from the (collusive) prices on which the algorithms have converged (the grey dotted line), we override one algorithm’s choice (the red line), forcing it to deviate downward to the competitive or Nash price (the orange dotted line) for one period. The other algorithm (the blue line) keeps playing as prescribed by the strategy it has learned. After this exogenous deviation in period , both algorithms regain control of the pricing.

Figure 1 Price responses to deviating price cut

Note: The blue and red lines show the price dynamic over time of two autonomous pricing algorithms (agents) when the red algorithm deviates from the collusive price in the first period.

The figure shows the price path in the subsequent periods. Clearly, the deviation is punished immediately (the blue line price drops immediately after the deviation of the red line), making the deviation unprofitable. However, the punishment is not as harsh as it could be (i.e. reversion to the competitive price), and it is only temporary; afterwards, the algorithms gradually return to their pre-deviation prices.

…The collusion that we find is typically partial – the algorithms do not converge to the monopoly price but a somewhat lower one. However, we show that the propensity to collude is stubborn – substantial collusion continues to prevail even when the active firms are three or four in number, when they are asymmetric, and when they operate in a stochastic environment. The experimental literature with human subjects, by contrast, has consistently found that they are practically unable to coordinate without explicit communication save in the simplest case, with two symmetric agents and no uncertainty.

What is most worrying is that the algorithms leave no trace of concerted action – they learn to collude purely by trial and error, with no prior knowledge of the environment in which they operate, without communicating with one another, and without being specifically designed or instructed to collude.

Tacit collusion isn’t actually illegal since it’s virtually impossible to prove, at least among humans. Tacit collusion by AIs is going to be much more common but perhaps also easier to prove if the antitrust authorities can demand access to the algorithms. No need to torture the data when you can torture the AIs. It’s going to be a strange world.

Hat tip: Ankur Delight.

Women in Economics: Elinor Ostrom

Our first episode in the Women in Economics series is an introduction to Elinor Ostrom, the first woman to have won the Nobel Prize in Economics. Elinor Ostrom and Vincent Ostrom have long been a part of the intellectual foundations of “Masonomics”. Both the Ostroms were past presidents of the Public Choice Society, for example, as were Jim Buchanan, Gordon Tullock and Vernon Smith. The Mason Economics department was thrilled when Ostrom won the Nobel as there has been and continues to be fruitful interaction between public choice, experimental economics and institutional analysis.

At the Women in Economics website you can also find Ostrom’s Nobel Prize address, more on the tragedy of the commons, and other resources.

Especially valuable for in-depth research are Vlad Tarko’s biography of Elinor Ostrom and Paul Dragos Aligica and Peter Boettke’s introduction to The Bloomington School.

Buy (or Rent) Coal! The Coasean Climate Change Policy

Since climate change and what to do about it are in the news it’s time to re-up an underrated idea, buy coal! Carbon taxes increase the price of carbon and induce economic and technological substitution towards lower-carbon sources of fuel in the countries that adopt them. As carbon-tax countries reduce fuel use, however, non carbon-tax countries see the price of their fuel decline. Thus, unless all countries join the tax-coalition, there is leakage. Supply-side policies are an alternative to demand supply policies. The United States, for example, could buy out and close coal mines, including giving the workers substantial retirement/reallocation bonuses, thus reducing the world supply of coal which is still the largest source of C02 emissions.

You can get rich by hitting an oil gusher, but coal is relatively expensive to mine and to transport. Thus, it’s relatively cheap to buy out coal mines because you aren’t buying the coal, you’re buying the right to leave the coal in the ground. Cutting the supply of coal raises its price which will increase the quantity supplied in other countries. Thus, there is the potential for supply leakage as well as demand leakage. It’s probably easier to use more coal when the price of coal falls (electricity, for example, can be generated in a variety of ways) than it is to mine more coal when the price rises. In other words, the elasticity of the demand for coal is greater than the elasticity of supply so supply leakage is probably less than demand leakage. Furthermore, supply leakage can be handled by buying out supply in the non-coalition countries. As Noah Smith pointed out with the graph at right (data) US CO2 emissions are actually falling while the rest of the world keeps rising (as they catch up in per-capita terms) so addressing the CO2 emissions problem requires bringing countries like China and India on board.

Coal use in China is very high and increasing. India has been canceling coal plants as solar becomes cheaper but coal is still by far the largest source of power in India. Thus, there is plenty of opportunity to buy out, high-cost coal mines in China and India.

It might seem odd to buy Chinese and Indian coal mines but we buy Chinese and Indian labor, why not a coal mine? Moreover, it’s important to understand that the policy is to buy only up to the point that it benefits both parties. Buying coal isn’t foreign aid, it’s a pollution reduction plan just like a carbon tax or R&D investment and because we can buy barely-profitable coal mines and avoid the problem of leakage this is a low-cost method to reduce CO2 emissions.

Collier and Venables worry that foreign voters won’t like foreign investors buying up coal mines, although foreign investment is hardly uncommon and foreigners do protect rainforests by buying the right to cut them down. In any case, Collier and Venables suggest a cap-extract and trade program. Under cap-extract there is a cap on global extractions of carbon (not use) but rights to extract can be traded. Since it’s more valuable to extract say oil than coal what this would mean is that payments would flow from mostly developed countries to developing countries which makes it clear that we are all in the boat together.

Even without a cap-extract and trade program, however, there are other factors that make buying coal attractive to people in selling countries, namely coal is killing them even putting aside the dangers of climate change.

NYTimes: Burning coal has the worst health impact of any source of air pollution in China and caused 366,000 premature deaths in 2013, Chinese and American researchers said on Thursday.

Coal is responsible for about 40 percent of the deadly fine particulate matter known as PM 2.5 in China’s atmosphere, according to a study the researchers released in Beijing.

India’s air quality is even worse than China’s and is responsible for some 1.2 million early deaths annually. A 25% cut in pollution in India could increase life-expectancy by 1.3 years and in some highly polluted cities such as Delhi by 2.8 years. Not all pollution comes from coal but a substantial amount does.

Buyers might worry that a foreign government will take their money and later renege on the deal. There are lots of ways to deal with this problem–turn the coal fields into a national park, for example, or develop them for housing. But let’s turn a problem into a solution. Instead of buying coal, we could rent it. In other words, buy the right to delay mining the coal for say 10 years. Given the rate of improvement in solar, many coal plants will be uneconomic in 10 years and given the rate of improvement in living standards and the consequent increased demand for clean air, many coal plants in India and China could well be unpolitical in 10 years. Thus, it is true that some solutions are naturally in the offing, but for exactly this reason some coal plants are going to be working extra hours in the next decade to squeeze out what profit they can while they still can. We can avoid this last push of CO2 into the atmosphere by buying up the right to extract and holding it for a decade.

A program to leave coal in the ground could easily pay for itself in lives saved and climate stabilized.

Biblical Adverse Selection

And Jesus said, Behold, two men went forth each to buy a new car.

And the car of the first man was good and served its owner well; but the second man’s was like unto a lemon, and worked not.

But in time both men grew tired of their cars, and wished to be rid of them. Thus the two men went down unto the market, to sell their cars.

The first spoke to the crowd that had gathered there, saying honestly, My car is good, and you should pay well for it;

But the second man went alongside him, and bearing false witness, said also, My car is good, and you should pay well for it.

Then the crowd looked between the cars, and said unto them, How can we know which of ye telleth the truth, and which wisheth falsely to pass on his lemon?

And they resolved themselves not to pay for either car as if it were good, but to pay a little less than this price.

Now the man with a good car, hearing this, took his car away from the market, saying to the crowd, If ye will not pay full price for my good car, then I wish not to sell it to you;

But the man with a bad car said, I will sell you my car for this price; for he knew that his car was bad and was worth less than this price.

But as the first man left, the crowd returned to the second man and said, If thy car is good, why then dost thou not leave to keep the car, when we will pay less than it is worth? Thy car must be a lemon, and we will pay only the price of a lemon.

The second man was upset that his deception had been uncovered; but he could not gainsay the conclusion of the market, and so he sold his car for just the price of a lemon.

And the crowd reasoned, If any man cometh now to sell his car unto us, that car must be a lemon; since we will pay only the price of a lemon.

And Lo, the market reached its Nash equilibrium.

From username42 on Reddit. Hat tip: Michael Lane.

Your challenge: Explain an economics principle the King James Way.

Women in Economics

Tyler and I are very pleased to announce a new series at MRU, Women in Economics.

Women in Economics highlights the groundbreaking and inspiring work of female economists – not only to recognize the important work they’ve done but to also share their inspirational journeys.

Our first major video on Elinor Ostrom will be released on February 12 followed by videos on Janet Yellen (featuring Christina Romer and Ben Bernanke), Anna Schwartz (featuring Claudia Goldin), Joan Robinson and more. We also have some more informal “mini-testimonials” discussing the work of some major contemporary economists who have been inspirational. In the video below I discuss the work of Petra Moser. (I should have cleaned my office.)

Tyler and I also want to take a moment to thank the fantastic team at MRU for a huge amount of creativity, inspiration and hard work in putting this series together. Lots of thanks and appreciation to Roman Hardgrave, Alexandra Tooley, Mary Clare Peate, Brandon Davis, Justin Dile, Lindsay Moss and William Nava. You too can join the team!

More here.

Poor Sleep Makes People Poor: The Costs of India Standard Time

After Independence, India adopted a single time zone for the entire country. India spans as much 1,822 miles in the East-West direction or 29 degrees longitude. If India followed the convention of a new time zone every 15 degrees it would have at least two time zones. With just one zone the sun can rise two hours earlier in the East than in the far West.

In an original and surprising paper, Maulik Jagnani, argues that India’s single time zone reduces the quality of sleep, especially of poor children and this reduces the quality of their education. Why does a nominal change impact real variables? The school day starts at more or less the same clock-hour everywhere in India but children go to bed later in places where the sun sets later. Thus, children in the west get less sleep than children in the east and this shows up in their education levels and later even in their wages!

I find that later sunset causes school-age children to begin sleep later, but does not affect wake-up times. An hour (approximately two standard deviation) delay in sunset time reduces children’s sleep by 30 minutes. I also show that later sunset reduces students’ time spent on homework or studying, and time spent on formal and informal work by child laborers,while increasing time spent on indoor leisure for all children. This result is consistent with a model where sleep is productivity-enhancing and increases the marginal returns of study effort for students and work effort for child laborers.

The second part of the paper examines the consequent lifetime impacts of later sunset on stock indicators of children’s academic outcomes. I use nationally-representative data from the 2015 India Demographic and Health Survey (DHS) to estimate how children’s education outcomes co-vary with annual average sunset time across eastern and western locations within a district. I find that an hour (approximately two standard deviation)delay in annual average sunset time reduces years of education by 0.8 years, and children in geographic locations with later sunset are less likely to complete primary and middle school.

Addendum: The importance of sleep and coordination of sleep with circadian rhythms is also illustrated by the phenomena of teenagers who get more sleep and do better in school when school opening is better timed with adolescent sleep patterns. As a result, we are seeing a movement to push school opening times later for teenagers. Perhaps India will adopt a second time zone.

Columbus Lowered World Temperature

European germs killed 90% of the population of the Americas in the century after 1492 causing millions of hectacres of farm land to revert to forest which increased the uptake of carbon and reduced the planetary temperature. That is the upshot of a new paper that joins together previous estimates of population decline, farm land and carbon sequestration to push the onset of the Anthropocene to before the industrial revolution.

Earth system impacts of the European arrival and Great Dying in the Americas after 1492.

Abstract: Human impacts prior to the Industrial Revolution are not well constrained. We investigate whether the decline in global atmospheric CO2 concentration by 7–10 ppm in the late 1500s and early 1600s which globally lowered surface air temperatures by 0.15C, were generated by natural forcing or were a result of the large-scale depopulation of the Americas after European arrival, subsequent land use change and secondary succession. We quantitatively review the evidence for (i) the pre-Columbian population size, (ii) their per capita land use, (iii) the post-1492 population loss, (iv) the resulting carbon uptake of the abandoned anthropogenic landscapes, and then compare these to potential natural drivers of global carbon declines of 7–10 ppm. From 119 published regional population estimates we calculate a pre-1492 CE population of 60.5 million (interquartile range, IQR 44.8–78.2 million), utilizing 1.04 ha land per capita (IQR 0.98–1.11). European epidemics removed 90% (IQR 87–92%) of the indigenous population over the next century. This resulted in secondary succession of 55.8 Mha (IQR 39.0–78.4 Mha) of abandoned land, sequestering 7.4 Pg C (IQR 4.9–10.8 Pg C), equivalent to a decline in atmospheric CO2 of 3.5 ppm (IQR 2.3–5.1 ppm CO2). Accounting for carbon cycle feedbacks plus LUC outside the Americas gives a total 5 ppm CO2 additional uptake into the land surface in the 1500s compared to the 1400s, 47–67% of the atmospheric CO2 decline. Furthermore, we show that the global carbon budget of the 1500s cannot be balanced until large-scale vegetation regeneration in the Americas is included. The Great Dying of the Indigenous Peoples of the Americas resulted in a human-driven global impact on the Earth System in the two centuries prior to the Industrial Revolution.

A MimbleWimble Explainer

TechnologyReview: In July 2016, someone using the name Tom Elvis Jedusor (the real name of Lord Voldemort, the main villain in the Harry Potter universe, in the French edition) posted a link to a text file in a chat room frequented by Bitcoin researchers. Voldemort’s document described MimbleWimble, a blockchain system that would hide the identifying information associated with Bitcoin transactions.

…The person who started Grin [one of the first new currencies built on a blockchain that implements MimbleWimble] is also pseudonymous, going by the name Ignotus Peverell (the original owner of Harry’s invisibility cloak), and has never been seen. Peverell recently used a text-to-speech program to address attendees at a Grin conference.

So to sum up, Grin is a new currency on the MimbleWimble blockchain imagined by Lord Voldemort and implemented by the invisible Ignotus Peverell.

…Eric Meltzer, an investor for crypto-focused Primitive Ventures, recently estimated that $100 million of “mostly VC money” has already been invested in Grin mining operations.

Biotech on the Blockchain?

Bloomberg: In a novel approach for the biotechnology industry, small-cap company Agenus Inc. is aiming to raise $50 million to $100 million by issuing digital securities backed by future sales of an experimental cancer drug.

The digital securities will allow investors to bet on future sales of single products and will have a limited impact on shareholders’ equity, the company said. Agenus plans to offer at least 25 million of what it calls biotech electronic security tokens, or BESTs, to certain high-net-worth individuals and institutional investors starting Feb. 15.

I find this puzzling. First, why break out one drug from the rest of the firm? Investors generally want diversification and this is the opposite. Agenus is basically saying the rest of the firm is a value suck. Second, one of the virtues of the blockchain is that it allows for easy trade but the SEC requires that to buy these securities you must be an accredited investor and as such there are typically encumbrances on transfer. Thus, putting the securities on the blockchain doesn’t lower transaction costs, the way it could for other assets.

A lot of assets will be tokenized (i.e. securitized on the blockchain) in the future so this is an area to watch but to succeed tokenization must increase diversification and reduce transaction costs and this tokenization does neither.

The Buying Slow but Selling Fast Bias

In this clip professional money manager Ben Griffiths approvingly quotes fellow-trader Larry Williams, “If you get one thing right in your career it is to learn to be a slow buyer and a fast seller”. “If you can master that”, Griffiths continues “you will be well down the way to being a successful manager of money.” Using a huge database of 783 portfolios averaging $573 million in size and covering 4.4 million trades over 16 years, Akepanidtaworn, Di Mascio, Imas, and Schmidt show that professional money managers follow exactly this advice and it is exactly wrong.

Professional money managers do well on their “slow”, buy decisions–somewhat surprisingly, well enough to beat benchmark portfolios. It’s on their “fast”, sell decisions that money mangers significantly underperform the market. Remarkably, the authors show that on average professional money managers would have done better had the chosen what to sell randomly. Why? On their buy decisions money managers put in effort–you can tell they are putting in effort because their buy decisions cannot be explained by simple heuristics based on past returns (such as buy past winners or buy past losers). On their sell decisions, however, managers do appear to follow a heuristic of selling their big past winners or past losers. See the graph where the blue buy decisions are independent of past returns while the red sell decisions show a clear preference to sell positive or negative return outliers. The authors show that this bias reduces return (just as you would expect). When you sell fast you sell what comes to mind quickest, an availability bias, and that’s often a past winner or a past loser even if greater thought would convince you that these are not the best stocks to sell. The sell fast bias, however, is pretty easy to fix. I expect that institutional investors will induce money managers to take a second look at sell decisions, much as computer systems now ask physicians to check branded prescriptions when generics are available.

Addendum: In related news, Deep Mind’s Alpha Star trounced human players of StarCraft II, a game of imperfect information that is much more complicated than chess. Amazingly, Alpha Star made fewer actions per minute than the human players. As with GO the AI developed new long-range strategies never before seen.