Returning borrowers have better default rates

Andrey Kamenov

Andrey Kamenov, Ph.D. Probability and Statistics

We saw in a recent post that Prosper’s own rating system provides relatively accurate results. However, there is some confusion as to whether it takes returning borrowers into account. As we will show in this post, it is possible to improve upon the standard rating system, thanks to the fact that the number of previous Prosper loans is readily available.

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U.S. economic growth: gross output

Alexander Fishkov

Alexander Fishkov, Ph.D. student Computer Science

Gross output represents the market value of all services and goods produced in a nation’s economy. This value differs slightly from gross domestic product (GDP), which is often used to measure the economic performance of a country. Gross output consists of products sold to final consumers (the GDP) as well as products sold to other industries where it is used as material or input. Today we will explore historical data (provided by the Bureau of Economic Analysis) on the gross output of the U.S. economy.

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Another look at gender equality in the U.S.

Andrey Kamenov

Andrey Kamenov, Ph.D. Probability and Statistics

One of the independent variables included in The Economist’s where-to-be-born index is gender equality. While various methods exist to measure gender equality, the one selected by the Economist’s Intelligence Unit (EIU) is based on the share of seats in government held by women. In theory, this approach won’t work well in cases where women constitute the majority — in reality, however, that’s unfortunately almost never the case.

So how does the U.S. fare here? Let’s start with the historical perspective.

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How Geography Affects Your Health

Benjamin Schultz

Benjamin Schultz, Ph.D. Geography

One of the most common New Year’s resolutions is to start working out and get back in shape. While this is a noble goal, experience and evidence show that two out of every three people lose sight of their New Year’s fitness plans after just a few weeks.

This state of affairs is particularly relevant considering that one of the defining issues of the Obama presidency was health care. Lifestyle, diet, and a commitment to personal fitness are major factors in controlling the high cost of health care.

Most Americans are well aware of this, but data show that many people continue to engage in a variety of unhealthy activities and do not get enough exercise. It turns out, however, that the extent to which people lead an unhealthy lifestyle has a strong geographic component. In other words, some places display healthier behaviors and have a healthier population than others.

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How long does it take to build a house in 2017?

Andrey Kamenov

Andrey Kamenov, Ph.D. Probability and Statistics

Ever wonder how long, on average, it takes to build a house? According to the most recent data from the U.S. Census Bureau’s Survey of Construction, it takes nearly seven months on average. More than half (52.4 percent) of all new housings are finished within five months (compared to just 46.7 percent 10 years ago), and 93 percent are completed within one year.

Of course, these numbers don’t come close to telling the whole story. Let’s see what the primary factors are that influence the duration of construction.

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The revenue and net sales of Samsonite

Pavel Prikhodko, Ph.D. Machine Learning

Luggage retail is an important global market. In 2014, American jewelry, luggage and leather goods store sales amounted to around $34.24 billion. This is a slight increase over the previous year’s total of around $34.13 billion.

The American company Samsonite is the largest luggage manufacturer and retailer, with products ranging from large suitcases to small bags and briefcases. Samsonite was founded in Denver, Colorado in 1910. The timeline below shows us the total global revenue of the world’s largest luggage manufacturer from 2007 to 2015. In 2015, Samsonite’s global revenues amounted to about $2.43 billion. This is a slight increase from 2014 when the company generated about $2.35 billion in revenue.

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The “half your age plus seven” rule — how often is it broken?

Andrey Kamenov

Andrey Kamenov, Ph.D. Probability and Statistics

When is an age difference between partners a little too large? A common rule is that you cannot date someone younger than half your age plus seven. For example, if you are 30, dating someone 22 years old is just barely acceptable.

The following chart illustrates this concept: couples between the dashed lines are the ones following the rule.

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The Biggest Killer in Africa

Andrew B. Collier

Andrew B. Collier, Ph.D. Physics

Gorilla Fever

A few weeks ago, my wife developed a fever. Many people had colds and the flu at the time, so we were not too concerned. As it was a Friday afternoon, the best treatment seemed to be a quiet weekend of recuperation. She took the normal things: Vitamin C and aspirin. The fever waxed and waned over the course of the weekend, and I persuaded her to take Monday off work. She went to see her doctor, who confirmed that she had a bad case of the flu. The doctor thought that she was also a little anemic, so took blood samples which were sent off for testing.

By Monday evening, my wife was feeling pretty decent. The next morning she was feeling fine, so she went off to work. However, at some stage during the day the fever returned, much worse than before. She left work early. While she was on her way home, the doctor called to say that the results of the tests had come back and her red blood cell count was dangerously low. She was to be admitted to hospital immediately.

Sometime later that night, after a barrage of further tests, the hospital physician announced that she had malaria.

We live in South Africa, a few hundred kilometers from the nearest malaria area. However, two months earlier, my wife had been on a short trip to Uganda. The strain of malaria which she had contracted is not found in South Africa but is present in Uganda. Evidently, she picked it up during her trip (despite taking potent prophylactics), and it had remained dormant in her system until recently.

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Are actor names a popular choice for babies?

Andrey Kamenov

Andrey Kamenov, Ph.D. Probability and Statistics

How do people choose names for their children? It’s no secret that quite a few name their boys and girls after different celebrities — actor names seem to be one of the common choices.

Is this truly the case? Were there a lot of Dustins born right after “Rain Man” hit the cinema screens? Let’s take a look.

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Age distribution among same-sex couples

Alexander Fishkov

Alexander Fishkov, Ph.D. student Computer Science

In this post, we will continue to investigate same-sex couples and their demographic features. We will once again use American Community survey data, namely the ACS 2015 five-year sample processed by the IPUMS project. In this version, IPUMS USA has introduced a specially-constructed variable to their version of American Community Survey. Using answers to different questions of the survey form, they attempt to pinpoint the location of the respondent’s potential spouse in the same household. This allows us to identify both same- and opposite-sex couples.

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