What Are the Chances?

Musings on everyday probability

New York City: have we hit the peak?

April 3, 2020 By Olivia Hebner

There may be some good news today.

What is R0 and why do you care?

April 3, 2020 By Josh Lafair

Josh will tell us about R0, the base reproduction number of a disease, and why we need to worry about it.

Louisiana, Michigan, and New Jersey Surpass Washington

April 2, 2020 By Alan Salzberg

Washington State continues to flatten.  Not so for other states.

State Virus Update

March 31, 2020 By Alan Salzberg

We made it through the weekend.  Is Lousiana still the worst?  Maybe.

Which state is the next New York, continued.

March 27, 2020 By Alan Salzberg

New York has by far the most deaths, followed by Washington State, but Washington won't be the second state to hit 1,000 deaths.  Here's why.

Which states are the next NY?

March 24, 2020 By Alan Salzberg

You've probably heard a lot about New York being the center of the outbreak in the US.  That's true, but due to their testing, NY looks much worse than other areas when it's only a little worse than some.  What areas should we be worried about?

It's all about stopping exponential growth

March 22, 2020 By Alan Salzberg

Right now, in the US, deaths from COVID-19 are still increasing at an exponential rate.  This means they double every few days.  A shutdown in other countries, like we have in NY, quickly curbed infections -- that is the only explanation for the end of exponential growth in China, and now in Italy.

DeBlasio is spreading lies and panic in NYC. But the real place that should be worried? Florida.

March 20, 2020 By Alan Salzberg

Our NYC mayor is freaking out because of the dramatic increase in cases.  He's wrong.  

Coronavirus Death Rate in US Worst in the World?

March 8, 2020 By Alan Salzberg

The current death rate in the U.S. for the coronavirus is more than 4%.  But it's way too high, and that's bad news.  

Vaccines are good, but this article about them isnt!

January 15, 2020 By Alan Salzberg

The evidence that showing vaccines are safe and that they save lives is generally overwhelming, so I'm always pleased to see another article reviewing the data behind them. I figure such articles will lead to even more people being vaccinated and more lives saved.

However, I was disappointed that a recent New York Times article did the statistics so poorly. The article compares 10,000 people who got various diseases with 10,000 people who were vaccinated. This comparison is inappropriate, because most people who do not get vaccinated do not get the disease they are being vaccinated for, and, especially for diseases like the flu, many people who do get vaccinated get the disease they were vaccinated for. A proper comparison would compare some number of people who were vaccinated against the same number who were not vaccinated.

Statistics in Court. Lesson 2: The Made-up Probability

April 30, 2019 By Alan Salzberg

Lesson 2: The Made-up Probability

My prior discussion regards improperly multiplying probabilities when using statistics in court.  But what about when someone simply makes up the probabilities?  Surely, that wouldn’t happen in a court of law would it?

Statistics in Court. Lesson 1: Beware multiplying probabilities.

April 24, 2019 By Alan Salzberg

This is the first in two blogs regarding incorrect use of statistics in court.

The chances that a randomly selected man will be 7 feet tall or more is about one in a million. So it follows that the chance of two randomly selected men being 7 footers is the square of one in a million, which is one in a trillion, right?


Does this graph tell the real story about wages for low-skilled workers?

January 13, 2019 By Alan Salzberg

An article and accompanying graph in the New York Times claims that low-skilled workers are not gaining the advantage they once were by moving to big cities.  But it misses something important, calling the whole claim into question.

Will your luck turn?

May 31, 2018 By Alan Salzberg

In the third quarter of the NBA Eastern Conference Finals last week, Boston missed all 14 3-pointers they attempted.  This led the announcer to say something like, "by the law of averages, they are bound to improve."  But will they?

Winning an election by 1 vote. What are the chances?

December 20, 2017 By Alan J. Salzberg
Voting is thought of as the most important civic duty.  But does your one vote really count?  I mean, how many elections are won by just a vote?  Certainly not many.  Yet, I just read that in Virginia...