Andrey Kamenov, Ph.D. Probability and Statistics
Andrey Kamenov is a data scientist working for Advameg Inc. His background includes teaching statistics, stochastic processes and financial mathematics in Moscow State University and working for a hedge fund. His academic interests range from statistical data analysis to optimal stopping theory. Andrey also enjoys his hobbies of photography, reading and powerlifting.
One in every 20 Americans (among those in the labor force) has more than one job. But that number alone doesn’t tell us the whole story.
The fact is, this number is decreasing: While the exact percentage was 5.6 percent in 2000, it’s now down to 4.7 percent. The decline primarily took place before 2010, and the numbers haven’t changed much since then.
The incidence rate for diabetes keeps rising in the U.S. Since 2001, it has increased from 6.8 to 11 percent for men and from 8.8 to 12.2 percent for women. This means that more than one in every nine adults now suffers from this condition.
Today we are going to take a look at the numbers behind this increase — what are the major factors contributing to the increase?
First, here’s the map showing the states where growth has been the most significant.
Unsurprisingly, different car brands take different approaches to crafting their images. Some try to appeal to younger audiences, focusing on factors such as driving agility and design. Others emphasize luxury or practicality — things older drivers are more likely to be looking for.
Arecent study published by CarMax shows which brands have the youngest buyers. Naturally, this study only focuses on the used car market. The study also doesn’t account for the length of ownership; a man in his 50s driving a Corvette may have bought it 20 or 30 years ago.
So, which car brands are the most popular with younger drivers? Here’s what we found, based on the 2017 National Household Travel Survey. One thing to note: The average American driver is now 48.4 years old (compared to 43.4 in 2009). To make the results more informative, we capped the drivers’ age at 60.
We have already seen that regular exercise is better for your health in almost every aspect than the recommended seven hours of daily sleep. Let’s take a look at where the U.S. population stands on the issue.
According to a U.S. Environmental Protection Agency press release dating back as far as 1974, average outdoor noise levels below 55 dB “are identified as preventing activity interference and annoyance.” At the same time, more than 18.5 million Americans live in areas where the average existing noise levels are above this threshold.
Two states, New York and Illinois, stand out on the map below. The shares of the total population of these states living in areas with high noise levels are 18.1 percent and 15.7 percent respectively. The percentage registered in California is surprisingly small for such a densely-populated and urbanized area: only 1.5 percent.
Last year, Tesla CEO Elon Musk said that the brand’s fatality rate is “four times better than average.” As NHTSA has released the data for roadside fatalities in 2017, we can finally put this claim to the test, and it appears that Mr. Musk was not far from being correct. As the chart below shows, Tesla’s cars appear much safer compared to other luxury makes — in fact, there was only a single fatality in the entire year.
The main challenge is in estimating the total number of miles traveled by each make. The National Household Travel Survey can provide a rough estimate for the months when it was held. However, this estimate doesn’t take into account the changes in the fleet numbers that occur over the course of the survey. This is especially important for Jaguar, which significantly increased its U.S. sales in 2016 — but above all, it’s a deal-breaker for Tesla, which continued to demonstrate exponential growth in sales until recently.
American car manufacturers’ shares of the U.S. car market are shrinking as more Americans than ever make the switch to foreign cars. Japanese makes are the most popular, with Korean and German manufacturers also gaining market share.
This video below shows how the popularity of different car manufacturers has changed since 1961.
The U.S. population is getting older — that’s a fact. How does the country’s aging population impact its economy? One of the most popular ways to represent the changes that come with an increase in life expectancy is the elderly dependency ratio.
As suggested by its name, the elderly dependency ratio is the ratio of the elderly population (65 years and older) to the working-age population (aged between 15 and 64).
The U.S. has long experienced a surprisingly low elderly dependency rate — it has hovered around 19 percent since the late 80s. Immigration was a major contributing factor. Another major contributor was baby boomers — this large demographic group didn’t start to leave the working age range until 2011.
To anyone considering renting out their property on Airbnb, there is one extremely important question: How often will my property be rented? Sure, the daily rate may seem attractive for many, but if you don’t attract a lot of guests, the whole offer may not be near as lucrative.
On average, the occupancy rate (the percentage of time your property is rented — and makes you money) hovers at just below 50 percent in the U.S. This, of course, largely depends upon your pricing strategy as well as the property’s location.
Another important factor that may influence your decision to create a listing on Airbnb is whether you would have guests year round. In some cases, it may be a wiser choice to make your space available for just a few months each year.