Scoring my 2020 Predictions

David Manheim
7 min readApr 7, 2021


This year definitely didn’t turn out the way I expected in January, but predictions predict the future, not what we thought. That’s kind of their point, actually. So here’s how I did, on this list. (I have had a number of other prediction sets, this just judges my 1-shot predictions that I publish yearly.)
Also, I wrote most of this back in January, but there were things unsettled, then forgot about this. So it’s going up now, in April.

Note: I put True / False at the front of each prediction to mark how it was decided.

Overall Brier Score: 0.1996
Personal questions: 0.2066
Non-Personal questions: 0.1981

Multi-year Curve:

US Politics:

True — The Senate Acquits Trump: 85%
False / False — Trump is removed from office / barred from running in 2020: 2% / 1%
False — They don’t have the trial, or it’s delayed until after 2020, or they pick some stupid other option… : 13.5%

False— V.1 Trump wins the 2020 Election: 40% {V: 55%}

True / False / False / False — V.2 Biden / Warren / Sanders / Bloomberg is nominated: 40% / 15% / 20% / 2% (Updated after seeing Vox. It was 25% / 20% / 30% / 5% {V.Biden: 60%}

True — Democrats win both halves of Congress + Presidency: 40% (Updated after seeing Vox. This was 55%. I don’t disagree conditional on Biden winning, but think they’re overconfident on that.)

False — V.3 GOP holds the Senate: 55% {80%}

False — A third party candidate gets more than 5% of the vote: 15% (There’s a lot of room for people to vote for a relatively credible libertarian, if the party is smart [unlikely] or have an outsider on the right run a big independent campaign — especially if Trump looks very unlikely to win.)

False — V.4 Trump doesn’t get another Supreme court appointment in 2020: 85% {70%} (Side note: I think VOX is silly to look at SSA survival figures unadjusted, given the connection between wealth and survival rates.)

False— V.5 The Supreme Court will allow more abortion restrictions: 87.5% {90%} (I’m not an expert, but FantasyScotus seems pretty sure about this. Edit Jan 16th: Peter Hurford pointed out that I misread FantasyScotus, and that it’s a single prediction. So I’m reversing the strength and direction of my update, and moving down from my initial 97.5% to 87.5%.)

False— V.6 The Democratic primary will be settled on Super Tuesday (one candidate hits 90% in prediction markets by March 5): 45% {60%} (See above difference in predictions about who wins.)

True/True — US Markets, i.e. the S&P 500, drops more than 10%/20% from the highest point during 2020: 55%/35% (This is high, but I think there are lots of semi-expected surprises that could shock the market temporarily.)

Israeli Elections:

True — V.11a Netanyahu is prime minister after the Israeli elections: 55% (I called this one before Vox.)

True — V.11b Netanyahu will not be unseated as Israeli prime minister [at all in 2020]: 52.5% {55%}

False — Netanyahu’s party gets the most votes: 60%

False — There’s no coalition, and it goes to a fourth round: 35% (I’m optimistic that they get their act together after this last ridiculous round. Maybe I’m a dreamer, but…)

True/True/False/False — Arab parties have at least 10 / 12 / 14 / 16 (total) seats: 85% / 55% / 15% / 1%


True— V.7 The number of people in global poverty will fall: 70% {60%}

True — V.8 Brexit happens: 90% {95%}

True — V.9 No US troops land in Iran 85% {80%}

True — V.10 China’s internment camps for Muslims will remain open (85 percent)

Science and Technology

False — (In 2021, however…) V.12 No gene drives to fight malaria-carrying mosquitoes will be launched in any part of the world 85% {90 percent} (Mostly agree, but Vox isn’t really thinking about other groups doing small replications, etc.)

True — V.13 No new CRISPR-edited babies will be born: 85% {80 percent}

Unclear / Mulligan per Vox — V.14 The number of drug-resistant infections will increase: 85% {70 percent}

Right — V.15 Facial recognition will be banned in at least three more cities: 80% {70 percent} (I just think it’s so easy for city councils to do this.)

Animal welfare and the environment

Right — V.16 Beyond Meat will outperform the general stock market 55% {70 percent} (Markets are efficient, growth is expected, and underperformance shocks are common.)

False— V.17 Global carbon emissions will increase 85% {80 percent}

True — V.18 Average world temperatures will increase relative to 2019 65% {60 percent}

True — V.19 California has a wildfire among the 10 most destructive in state history 40% {60 percent} (I think they are overweighting recent events, and ignoring the fact that response teams will be extra on the lookout / overzealous now.) {I was just wrong. The causes of the trend seem to be stronger than the reactions, maybe?}

New Long-term Predictions:

There will not be a large (1,000 people or more) uninvited ground invasion of a foreign country by the US by 2025: 85%

Nuclear weapons will not be used before 2025: 85%

No new countries (with the possible exception of Israel) will test or otherwise announce possession of nuclear weapons before 2025: 80%

There will be no new inter-state war killing more than 1m / 500k / 250k people before 2025: 80% / 75% / 40%

SpaceX will land a rocket / a human on Mars by 2030: 40% / 20%

SpaceX will still have significant plans for going to Mars in 2030: 75%

Added Jan 14, from JThompson, predicting the year 2030. My specific claims were added (He seems very tech-pessimistic once you look at the type of specific joint claims being made…)

JT.1 Very few people will be using flying taxis, other than those already using conventional flying taxis.
Fewer than 25,000 flying cars are sold in 2029: 60%

JT.2 Very few people will be being driven by autonomous vehicles.
Less than 5%/25%/75% of cars manufactured in the US in 2029 will be capable of autonomous operation (level 5:) 15%/40%/85%
Autonomous L5 operation will not yet be legal in most US States: 40%

JT.3 Most cars will be powered by internal combustion engines.
More than 5%/25%/50%/90% of cars sold in 2029 will be internal combustion: 90%/65%/55%/15%

JT.4 Batteries will be only a little better than they are at the moment.
In 2029, for home and power station batteries, the cost per kW of battery power will be above $500, and the cost of battery energy will be above $1,000USD/kWH: 30%
In 2029, small ~5V, rechargable phone-type batteries, the cost will be above $50 for a 500-cycle (to 80% capacity) battery, and no such batteries with >2,000-cycles will be available for less than $1,000. (All amounts in adjusted to 2019 USD): 30%

JT.5 People all over the world will be richer and healthier.
Global average lifespan will be higher than in 2019: 80%
Fewer than 0.5 billion will live in absolute poverty: 75%
Median per capita global income in 2029 will be above $5,000/$10,000/$15,000: 85%/65%/25%

JT.6 Population growth will stabilize, except in Africa.
In 2029, global population growth outside of Africa will be below 0.5%/0.25%/0%: 60%/40%/10%
In 2029, population growth in Africa will be below 1%/0.75%: 95%/80%

New Jan 16th: A song written via computer-generation of lyrics and music, and performed fully digitally without a human singer / musician, not involving AGI or general ability to communicate with others, will make the billboard top-100 (Or will qualify based on sales and play-time, but be ruled out for technical reasons, such as because it is computer generated,) by 2030/2040: 70%/90%

Prior Long-term predictions:

False — (2017) There will be a Republican primary challenger getting >10% of the primary vote in 2020 (conditional on Trump running): 5% (I said 70% in 2017, then 60% in 2019)

False, somehow — (2017) The S&P will go down under President Trump (Conditional on him having a 4 year term, Inauguration-Inauguration:) 10% (Was 60% in 2017–2019.

? — (2018) The retrospective consensus of economists about the 2017 tax bill will be;
…didn’t increase GDP growth more than 0.2%: 96% (was: 95% in 2017. Pretty happy with this one.)
…that, after accounting for growth, it increased the 10-year deficit more than $1tr / $1.2tr / $1.5tr, respectively: 93% / 80% / 45% (Happy with this one too. Staying the same since 2019. In 2017, it was: 90% / 70% / 40%.)

False — (2018) Conditional on impeachment, the senate will convict: 4% (was 20% in 2018, then 10% in 2019.) (2018 Comment: Most uncertainty is if he does something additionally crazy, crazy enough to prompt short term worries about safety/stability.) [2019 Comment: We’ll see. But I was underestimating the crazy that people would be OK with, and also underestimating how likely he was to do something that’s objectively and clearly illegal misuse of power.] 2020 Comment: Oh how naive I was.

True — (2018) AI wins a Real Time Strategy game (RTS — Starcraft, etc.) in full-mode against the best human players before end of;
Probably? Unclear — 2020–75% [Was 60%.]
Within Byun Hyun Woo’s Lifetime: 99.5% [Was 98%]


False— I take a job (not just contracting) in 2020: 40%
True/True/True- My Google Scholar H-Index hits 7/8/9: 80%/40%/15%
Invalidated — I attend 2020 Bxx Mxx: 50% (Cancelled)
False — I get accepted to Exxx 2020: 35%
True — I continue working with F: 85%
True / True— I submit the Postdoc Paper / it is accepted for publication in 2020: 95% / 85%

True — 4 xxxxxxxx by 1/1/2021: 30%