Tag Archives: Chicago Booth

Updates from Chicago Booth

Machine learning can help money managers time markets, build portfolios, and manage risk
By Michael Maiello – It’s been two decades since IBM’s Deep Blue beat chess champion Garry Kasparov, and computers have become even smarter. Machines can now understand text, recognize voices, classify images, and beat humans in Go, a board game more complicated than chess, and perhaps the most complicated in existence.

And research suggests today’s computers can also predict asset returns with an unprecedented accuracy.

Yale University’s Bryan T. Kelly, Chicago Booth’s Dacheng Xiu, and Booth PhD candidate Shihao Gu investigated 30,000 individual stocks that traded between 1957 and 2016, examining hundreds of possibly predictive signals using several techniques of machine learning, a form of artificial intelligence. They conclude that ML had significant advantages over conventional analysis in this challenging task.

ML uses statistical techniques to give computers abilities that mimic and sometimes exceed human learning. The idea is that computers will be able to build on solutions to previous problems to eventually tackle issues they weren’t explicitly programmed to take on.

“At the broadest level, we find that machine learning offers an improved description of asset price behavior relative to traditional methods,” the researchers write, suggesting that ML could become the engine of effective portfolio management, able to predict asset-price movements better than human managers. more>

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How sales taxes could boost economic growth
By Dee Gill – The fight against sluggish global economic growth has been expensive, protracted, and unexpectedly vexing, leaving central bankers in developed economies with a laundry list of shared frustrations. Meager economic growth, flagging wages, and low inflation persist, in spite of bankers’ monetary stimuli, and threaten to quash upward mobility for young job seekers and midcareer employees in even the richest countries.

There’s a poster child for what countries do not want to become: Japan. The former economic powerhouse has been stuck in low-growth purgatory since 1991. And yet, as much as they’d like to avoid it, some countries have been sliding in that direction.

Many big economies are stagnating, and economists are running out of options to fix them. The conventional monetary policy for encouraging spending has been to drop short-term interest rates. But with rates already near, at, or below zero, that method is all but exhausted. Some economists have also started to empirically and theoretically question the power of forward guidance, in which central banks publicize plans for future interest-rate policies, at the zero lower bound.

Central banks and governments badly need a new stimulus tool, preferably one that doesn’t cost a lot of money. Some researchers are proposing a fix that might sound unappetizing: raising sales taxes as a means of jump-starting economic growth.

Francesco D’Acunto of the University of Maryland, Daniel Hoang of Germany’s Karlsruhe Institute of Technology, and Chicago Booth’s Michael Weber find evidence that a preannounced tax hike—a 3-percentage-point increase in Germany’s Value Added Tax enacted in 2007—provided just the kind of growth stimulus central banks desperately need today. more>

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How local productivity growth affects workers near and far
One city’s boom can be felt across a nation
Chicago Booth – When big cities experience an economic boom, you expect an upsurge in wages and growth in those areas. But there’s some nuance: according to Chicago Booth’s Richard Hornbeck and University of California at Berkeley’s Enrico Moretti, one area’s surge particularly benefits low-skilled workers locally—and high-skilled workers elsewhere.

Using total factor productivity (TFP) as a measure of local productivity growth, Hornbeck Amount and Moretti analyzed two decades of data from major US cities to quantify the direct effects on people living in booming cities and the indirect effects on people elsewhere. Allowing for trade-offs between salary and cost-of-living increases, as well as unequal distribution of benefits across different groups, the researchers find that low-skilled workers gained the most from local productivity growth.

But gains extended further afield: a boom in San Diego or Los Angeles, say, was also felt in other cities. And high-skilled workers gained more from productivity growth in other cities. more>

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Given an out, people still fall back into debt
Research finds that keeping people out of debt traps isn’t as simple as paying off their loans
By Dee Gill – To the frustration of financial counselors everywhere, millions of people doom themselves to perpetual debt by repeatedly taking out small but expensive short-term loans they can barely afford. In the United States, these typically come from payday or car title lenders and go to financially strapped individuals.

In developing countries, small-scale entrepreneurs rely on daily or weekly loans for working capital. In both cases, borrowers pay exorbitant interest rates and, often, additional fees to extend a loan over and over. Interest payments can quickly add up to more than the loan amount.

Understanding how people get sucked into these debt traps is an important public-policy issue, according to Northwestern’s Dean Karlan, Chicago Booth’s Sendhil Mullainathan, and Harvard’s Benjamin N. Roth.

They conducted a series of experiments with indebted entrepreneurs in India and the Philippines and find that having their short-term loans paid off took the participants out of debt only temporarily. The entrepreneurs in question quickly took out new, profit-sapping loans. more>

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Raghuram G. Rajan says capitalism’s future lies in stronger communities
By Raghuram G. Rajan – You have a new book out called The Third Pillar. What is the third pillar?

It is the community. Around the world, there is widespread economic anxiety, domestic political tension, strife between countries, and now talk of a cold war reemerging between the United States and China. Why?

I argue that every time there’s a big technological revolution, it upsets the balance in society between three pillars: the political structure—that is, government or the state; the economic structure—that is, markets and firms; and the sociological, human structure—that is, communities.

When that balance is upset, we see anxiety and conflict, a signal that we’re striving for a new balance.

To really understand capitalism’s success, one has to understand the important role of the community. As it voices its concerns through democracy, the community is critical to maintaining the balance between the state and markets. When the community is appropriately motivated and engaged, it enables liberal market societies to flourish.

Recently, some communities have been weakened significantly while others have sped ahead. Technological change is creating a new meritocracy, but one that is turning out to be largely hereditary, denying opportunities to many. The many, in economically disadvantaged and thus socially dysfunctional communities, could turn their backs on markets. The consequent imbalances could undermine liberal democratic society. more>

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Purely evidence-based policy doesn’t exist
By Lars Peter Hansen – Recently, I was reminded of the commonly used slogan “evidence-based policy.”

Except for pure marketing purposes, I find this terminology to be a misnomer, a misleading portrayal of academic discourse and the advancement of understanding. While we want to embrace evidence, the evidence seldom speaks for itself; typically, it requires a modeling or conceptual framework for interpretation.

Put another way, economists—and everyone else—need two things to draw a conclusion: data, and some way of making sense of the data.

That’s where modeling comes in. Modeling is used not only to aid our basic understanding of phenomena, but also to capture how we view any implied trade-offs for social well-being. The latter plays a pivotal role when our aim is to use evidence in policy design.

This is intuitive if you think about the broad range of ideas and recommendations surrounding macroeconomic policy and the spirited, sometimes acrimonious way in which they’re debated.

If everything were truly evidence based, to the extent we can agree on the accuracy of the evidence, why would there be such heterogeneity of opinion? The disagreement stems from the fact that people are using different models or conceptual frameworks, each with its own policy implications.

Each of them might be guided by evidence, but policy conclusions can rarely be drawn directly from the evidence itself. more>

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Updates from Chicago Booth

Class action lawsuits hit innovative companies the hardest
By Alex Verkhivker – Corporate America has long complained that many class action suits are frivolous and an unfair tax on business. Lawyers have a financial incentive to file meritless suits because companies are often willing to settle—even when allegations are false—to save time, money, and public image. Lawmakers in Congress have wrestled with this issue for years without resolution.

But research suggests more reason to address it: the costs of such litigation weigh disproportionately on the most innovative US corporations, according to Chicago Booth’s Elisabeth Kempf and Tilburg University’s Oliver Spalt. Using data on more than 40,000 lawsuits filed between 1996 and 2011 against 6,111 companies, the researchers find that frivolous lawsuits tended to focus on highly innovative businesses, which represented juicy targets—and cost the average company in this group $1.1 million a year, or about 4 percent of annual profit gains. more>

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The tax that could save the world
By Michael Maiello & Natasha Gural – It was, perhaps, the closest that the economics profession has ever come to a consensus. In January, 43 of the world’s most eminent economists signed a statement published in the Wall Street Journal calling for a US carbon tax. The list included 27 Nobel laureates, four former chairs of the Federal Reserve, and nearly every former chair of the Council of Economic Advisers since the 1970s, both Republican and Democratic.

“By correcting a well-known market failure, a carbon tax will send a powerful price signal that harnesses the invisible hand of the marketplace to steer economic actors towards a low-carbon future,” the economists noted. All revenue from the tax should be paid in equal lump-sum rebates directly to US citizens, they added.

Not all economists agree that the tax should be revenue neutral in this way, but the profession has been coalescing in recent years around the idea of a carbon tax. Most prefer such a tax to the most prominent alternative policy for tackling carbon emissions, cap and trade, according to a recent poll of expert economists.

But a carbon tax seems to be a political nonstarter in the United States. The bipartisan call for action from economists over the years has been echoed by a failure to act by presidents from both parties. President Donald Trump denies the need to confront man-made climate change.

But although Barack Obama, his predecessor, in 2015 called a carbon tax “the most elegant way” to fight global warming, he didn’t push strongly for one to be introduced.

“One of my very, very few disappointments in Obama when he was president is that he did not come out in favor of carbon tax,” Yale’s William D. Nordhaus told the New York Times last October, days after winning the 2018 Nobel Prize in Economic Sciences for his work on economic modeling and climate change. more>

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Updates from Chicago Booth

What causes stock market crashes, from Shanghai to Wall Street
By Michael Maiello – The Shanghai Stock Exchange reached a historic peak in June 2015, and then plunged, losing almost 40 percent of its value in a month. This crash of the world’s second-largest stock market evoked comparisons to the 1929 Wall Street collapse, and provided a laboratory for testing an enduring explanation of its causes.

It has long been theorized that the 1929 crash reflected “leverage-induced fire sales,” according to University of International Business and Economics’ Jiangze Bian, Chicago Booth’s Zhiguo He, Yale’s Kelly Shue, and Tsinghua University’s Hao Zhou. They acknowledge that the theory has been well-developed to explain how excessive leverage makes investors sell in emergency conditions, accelerating market crashes. But they suggest that, until now, the empirical research has been lacking—and the China crash finally offers empirical evidence.

The researchers analyzed account-level data for hundreds of thousands of investors in China’s stock market. Because leverage was introduced in mainland China only in 2010, Bian, He, Shue, and Zhou were able to examine the implications of leverage-limiting regulations imposed in this decade. During the first half of 2015, there were two sources of leverage for Chinese investors—regulated brokerage houses and nonregulated online lending platforms. The latter, along with other nonbank lenders such as trust companies, formed the shadow-banking industry in China. The researchers thus studied the effects of each type of borrowing. more>

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Updates from Chicago Booth

Why artificial intelligence isn’t boosting the economy—yet
By Alex Verkhivker – Measured productivity has been declining for more than a decade in the United States and abroad. It calls to mind Solow’s paradox, a 1987 observation by the Nobel laureate economist Robert Solow, who noted that one “can see the computer age everywhere but in the productivity statistics.”

It shouldn’t be a surprise that the same thing is happening with artificial intelligence, or AI, according to MIT’s Erik Brynjolfsson, MIT PhD candidate Daniel Rock, and Chicago Booth’s Chad Syverson.

AI is a once-in-a-lifetime, general-purpose technology that promises to provide an “engine of growth,” they write. This was also true of the steam engine, electricity, and the internal combustion engine.

And yet, the researchers point out, the steam technologies that drove the US industrial revolution took nearly 50 years to show up in rising productivity statistics. And the first 25 years after the development of the electric motor and internal combustion engine were associated with a productivity slump, with growth of less than 1.5 percent a year. Then in 1915, the pace of economic expansion doubled for 10 years.

In these cases, the researchers find signs of what they call “the productivity J-curve,” a period in economic data when productivity growth is underestimated, followed by a period when it’s overestimated. This dynamic may have also applied to the computer-powered information-technology era, with 25 years of slow productivity growth followed by a decadelong acceleration, from 1995 through 2005.

Why does this happen? more>

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