Grading my 2020 predictions

In December 2019, I made 132 probabilistic predictions for 2020. As promised, I've come back to evaluate them on three criteria: calibration, personal optimism/pessimism, and performance relative to PredictIt (and an anonymous friend who sent me their predictions for some of the events). I'll get to all of those, but first, here are my predictions, … Continue reading Grading my 2020 predictions

Predictions for 2021

Just as I did last year, I have some probabilistic predictions for 2021. In January 2022 I will return to grade them, just as in a week or two I'll grade my 2020 predictions. This year the predictions fall into four categories: U.S. politics (#1-17 below), COVID (#18-39), Miscellaneous (#40-53), and Personal (#54-100). Note that … Continue reading Predictions for 2021

Was Nate Silver’s model wrong?

Nate Silver's model at FiveThirtyEight gave Biden an 89% chance to win the presidential election. He gave Democrats a 75% chance of taking back the Senate and a 97% chance of keeping the House. Then the election happened. Biden won -- though by a somewhat smaller margin than the model expected: Trump's 232 electoral votes … Continue reading Was Nate Silver’s model wrong?

An elegant proof of Laplace’s rule of succession

Suppose I give you a bag of marbles and tell you that all the marbles are either green or black. You repeatedly reach in, pick out a random marble, and then put it back. You find that out of 100 draws, 70 of the marbles you took out of the bag were green. What's the probability that the next marble you'll draw will be green? Or, to put it another way, what's your best guess (expected value) of the fraction of marbles in the bag that are green?

My 2020 Democratic primary predictions pass the smell test

FiveThirtyEight just published an impressive, sophisticated model of the 2020 Democratic primaries. If you're at all interested in the primaries, take a look -- there's a lot of cool stuff there (they also published a pretty detailed methodology which I also recommend reading). Conveniently, if you scroll down to the bottom of their forecast and … Continue reading My 2020 Democratic primary predictions pass the smell test

Predictions for 2020

In the spirit of Slate Star Codex, I will be offering some of my predictions for 2020. In January 2021 I will return to these and grade them. The predictions fall into three categories: US Politics (there are many of these since it's an election year), Personal (predictions about what I will do next year), … Continue reading Predictions for 2020