Yesterday I did my 10^th Ask Me Anything on Reddit. I love doing AMAs because the Reddit crowd as a whole is well-informed, Redditors don’t pull any punches, and good questions usually get voted up toward the top. This year I spent an hour taking questions about pandemic prevention, climate change, farmland, my cell phone, and much more. I wish I’d had time to answer even more.

Here’s a transcript of my favorite questions and my answers:

Redditor’s question: In the Netflix documentary series, one thing that was quite remarkable to me was how you and your team were able to design a nuclear reactor that produces uses already nuclear waste as a fuel. However this design was never implemented due to political reasons.My question is: Given that this technology has the potential to be the most-effective green energy source and have a key role in reversing climate change, what’s the current status on the project? Is it a likely possibility that this nuclear reactor will be built in the upcoming years? If so, do you plan on building in China or would you consider building such a project on US soil? Thanks.

My answer: We are still working on this. At first the project was a US-China joint venture but the US cancelled that. So now we are building the demo reactor in Wyoming where a coal plant is closing. It is very promising in terms of the cost and safety advances. If things go well a lot of these reactors will help solve climate change. Eventually we want reactors globally but the first ones will be in the US even though competing with natural gas electricity is hard here.

Do you have a medical degree? Then why are you getting involved in medicine? Why should your medical opinion matter?

The Foundation has a lot of Medical experts. It takes a huge range of skills to do things like Malaria eradication or Covid vaccines and therapeutics. I listen to the experts on specific medical advice. The system to prevent pandemics will require a lot more than just doctors so I wrote a book to start the discussion of what it should look like.

How do you see climate change happening in next 10-20 years? And how are we doing as a civilization to counter that? What's our biggest challenge?

The key is to be able to make things like electricity, steel, cement and meat without any emissions but at a cost equal or lower than today's cost. My efforts at Breakthrough Energy is to fund the innovators and help them scale up. I am optimistic because the progress on innovation in the last 3 years with the companies that have been funded is going very well.

Why did you pressure vaccine researchers not to open source the MRNA covid vaccines as was originally planned? Dont you think that wider access to this information would have increased access to vaccines at a critical time?

Our Foundation is funding the low cost vaccine manufacturers to do mRNA vaccines. They used other platforms for pandemic vaccines but in the future we will make sure they can do mRNA as well. We are funding mRNA to be used for HIV and Malaria. All the steps to get Covid vaccines out were done by the summer of 2020 and it lead to huge scaling up to put us in the oversupply situation we are in today. With the right technologies we can do it a lot faster and more equitably in the future.

How did you manage with stress during all of your class-action lawsuits of the 1990s and 2000s?

Although those lawsuits were tough I have been super lucky in my life and I had a good team of people working with me to help get them settled and move ahead.

Bill, thank you for taking the time. Big fan of both your work at Microsoft, Bill and Melinda Gates foundation and Berkshire Hathaway. I want to ask you about how most philanthropists think about RETURN ON INVESTMENT OF CHARITY. Most (billionaire) people doesn't seem to put much effort on it and just pick whatever subject they're most interested. As far as I understand, you option for epidemiology and sanitation was a diligent choice, because you think that money and a drive for business gives the most bang for the buck (some newspapers cover your fierce negotiation position to get us the vaccines, something that you are good at and I am thankful for).My question is. Do you think that most philanthropists are as diligent on their philanthropy as they were when they made their wealth? What are good themes where a drive for business can help the most?

I was stunned when I found out that a life could be saved for under $1000. This came when I read about what kids die of including the 1993 World Development report. So our Foundation (supported by Warren Buffett's incredible generosity) prioritized this. The success of our work in Global Health is well beyond what I would have expected. I do work with other philanthropists a lot including through the Giving Pledge where they can learn and be encouraged to be bold.

Mr. Gates, What are your thoughts on indoor farming?

For some high value crops it can work. For the cereal crops like wheat, rice and maize it is unlikely to ever be economic. We can improve seeds for all crops a lot to increase productivity - this is a key investment to help reduce the problems caused by climate change.

Can you a still jump over a chair from a standing start?

A smaller chair than I could do at age 30... Pretty small now. I try to stay fit playing a lot of tennis.

Took 4 doses of vaccine, 5G reception still bad. Any tips?
You need 5th one, with 4 you'll only get LTE at most

I must be wearing the wrong kind of tin foil hat because it doesn't work for me.

Hello Mr. Gates, huge fan of your work.What advice would you give young people who want to make a positive impact on this world?Greetings from Honduras.

The ideal thing is to read a lot and hopefully find a skill you enjoy that can have impact. For some that means being great at science or engineering. For some it means being a great communicator or politician. For some it means being a nurse or a doctor. The opportunity to learn is better today than ever before.

What is the future of nuclear power?

There is nuclear fission. If it can solve the cost, safety and waste concerns it can make a massive contribution to solving climate change. I am biased because I have been investing over a billion in this starting over a decade ago. Also promising is nuclear fusion. It is less clear if we will succeed but it has less safety and waste issues if it works. So I am hopeful nuclear will improve and be a huge help for climate.

What's the one thing you've bought that's brought you the most joy?

If we do succeed in polio eradication that will be super joyful. It has taken a lot of patience and great strategy to get close to success. The thing that has succeeded the best so far is funding vaccines for poor countries through GAVI. I do like burgers, nice tennis racquets and all the great streaming services but nothing too unique.

Your top 5 books of all time?

Two of Smil's latest Grand Transitions and How the World Really Works are great. Pinker has a lot of great books including The Better Angels of our Nature. I am just finishing the Coddling of the American Mind which was good. Ezra Klein's book on Polarization is good. Of course fiction books are more fun like Heart or A Gentleman in Moscow or All the Light you cannot see...

How are you guys preventing further strain mutations and vaccine adaptability of viruses for the "no more pandemics" goal?

We can make vaccines that have 3 additional things: broad coverage, long duration and infection blocking. These need to be R&D priorities to prevent pandemics but they will also be super helpful for all sorts of diseases.

Why is the COVID-19 model behaving very differently in America as compared to other countries? With state-of-the-art vaccines and close to 70% of people fully vaccinated, the cases are always rising after dipping for a few days. Looking at the statistics of the number of people catching COVID and the number of people dying due to it, seemed like this was to end by January / February. The model is quite weird.

The new variants come along and evade immunity from vaccination and infection. Also immunity wanes fairly quickly in the elderly. When the cases are high people do change their behavior and when they are low they go back to normal behavior. So you get huge ups and downs in the case rate driven by seasons, variants and people's behavior. Fortunately Omicron is less fatal than previous variants.

Which developing countries are you most optimistic about?

Some of the so called LMIC (Low Middle Income) countries have huge promise - Vietnam, India, Pakistan, Indonesia. In Africa it is important for Kenya, Tanzania, Nigeria and Ethiopia to succeed. Ethiopia was doing well until the civil unrest so hopefully they can get past that. Some of the smaller countries are doing well but we need the big ones to also do well.

What happened with the Oxford vaccine? Why wasn't it open source so that all countries could make it? I am so sad over how slow the vaccination in third world countries has been.

The world did not get the vaccines out in an equitable way. Places like India did well because the Gates Foundation, Serum and the Government of India worked together to make 1.4B doses of the Astra Zeneca vaccines. It was a tragedy that old people in countries like South Africa got vaccines after young people in other countries. My book talks about how we can do better next time. Today there is plenty of vaccine but still the distribution and demand is holding back coverage.

What are the biggest innovations in global and public health you expect to see in the next 5-10 years?

We are gaining understanding of malnutrition. Solving this would be huge for the 40% of kids in Africa who never fully develop their brains or bodies. We still need to prevent and cure HIV. We need to eradicate Malaria (which will take decades). We are close to eradicating polio. Other areas like better contraception or understanding and preventing pre-term birth and still births show promise.

Why do you think the world was utterly unprepared for Covid?

Infectious disease in rich countries isn't the big problem it used to be. For things like fire and earthquakes we have small ones to remind us of the problem. A pandemic that gets into Europe or the US only comes along rarely so it is easy to not practice and not have dedicated resources. A few countries like Australia did a better job and have 10% of the deaths of most rich countries.

I was in the 2nd cohort for the Gates Millennium scholarship. 💗 Just wanted to personally thank you for helping me be the 1st in my family to attend college. Do you still have any involvement with the scholar program?

Yes. The Foundation did 20,000 scholarships under the original program. We have an ongoing program that is not quite as big but still is attracting great students. I am always inspired when I meet the students who received the scholarship and are helping other kids.

How short are you on GME?

I have never been long or short gamestop.

What do you think the long-term impact of covid will be on society? I'm out in NYC and we are at a point where 1 in 5 people are catching covid and no one seems to be receptive of preventing the spread anymore. I ended up getting it last week despite being vaccinated and the symptoms were awful. Do you think there will be long-term ramifications of everyone going through covid in the next few months because people are unwilling to prevent the spread anymore?

Neither vaccination or infection prevents you from getting infected again but the disease will be milder and you will spread it less. Scientists funded by the Foundation are working on vaccines that prevent you from getting infected but those are 3-4 years away in the best case. So until then we will have to keep getting boosted (especially people who are older or who have co-morbidities).

What kind of phone do you have?

I have an Android Galaxy ZFold3. I try different ones. With this screen I can get by with a great portable PC and the phone and nothing else.

What's something I can do now to help with climate change?

As green products come out like electric cars or synthetic meat or heat pumps for home heating/cooling they will cost a bit extra. By buying these products you drive scaling up which will lead to lower prices so "green premiums" are reduced. Other than your political voice or influencing the company you work at this is probably the biggest thing you can do.

Hey Bill, what do you think about Bitcoin and cryptocurrencies?

I don't own any. I like investing in things that have valuable output. The value of companies is based on how they make great products. The value of crypto is just what some other person decides someone else will pay for it so not adding to society like other investments.

Quite a big chunk of the population of my country (for some reason) believes that you're the one responsible for the COVID-19 pandemic and that you're trying to take control of the human population by injecting chips in them through vaccines. What would you say to these people?

In 2015 I spoke out about my fears a pandemic would come up and cause tens of millions of deaths. My foundation funds vaccine research to save lives. I spend billions on vaccines and I am proud they have helped cut under 5 deaths in half over the last 20 years (from 10% to 5%). The idea of chips in the vaccines doesn't make sense. Why would I want to know where people are? What would I do with the information?

What do you think is the best way to combat misinformation / politicization of public health concerns by politicians or bad news outlets?

I keep looking for good idea of how to stop the bad information. Some stuff is obviously wrong and right now even that doesn't get stopped. The interest level in the crazy explanations make that spread really fast and the truth doesn't spread because it is boring. I feel bad if these rumors prevent people from getting vaccinated and boosted since that has saved millions of lives.

What do you plan to do with all the farmland you have purchased?

My investment team bought the farmland. It is less than .1% of all US farmland because the ownership is so diverse. We invest in the farms to raise productivity. Some are near cities and might end up having other uses.

What is an appropriate level of taxation for the rich?

A tax system needs to be progressive. Getting marginal rates above 60% often leads to a lot of complex avoidance if your system allows for that. It is strange to have the capital gain rate below the ordinary income rate. An estate tax could go somewhat above 60% - it is amazing how few countries have those.