What are your 5 most important facts?

What are the 5 most important facts that shape your worldview?

For me it would be:

  • Humanity is old: Homo Sapiens have been around for 300,000 years, and only writing for the past ~5,000.

  • We live way longer than people used to: As best we know, across all societies and times, half of children used to die. Now it’s 4%.

  • Almost everyone in the world is materially better off than almost everyone in history: Global average GDP per capita was about $1,000-1,500 until 1820. Now it is about $20,000.

  • Rich countries are vastly richer than poor countries: The income needed to be part of the global 1% is $65k/yr (after tax).

  • The universe is big. Like, really big. There are 10^23 stars, and the universe is 14 billion years old.

These facts are pretty undisputable.

I’m left with the view that:

  • My worries and troubles are pretty insignificant.

  • Things have gotten a lot better recently.

  • And there is a lot of collective work to be done to ensure they keep getting better.

What about you? What are the facts that shape your worldview?

A Map of Migration Policy Priorities

I’m trying to get my head around global migration.

Where do people move from and where do they go? Why?

How do countries prioritize different types of immigrants? And what can different systems learn from each other?

All of this with an eye towards informing where I, and others trying to do good in the space, should focus our energy.

At a basic level, a country that accepts immigrants has two big decisions to make.

  1. Do we want people to stay permanently, or just temporarily?

  2. What role will migrants play here? (working, accompanying family, studying, seeking refuge)

Below is my attempt to map how the world’s top immigration destinations have answered these two questions:

Up is permanent migrants, down is temporary. Right is work-driven migrants, left is not (family, students, refugees). Size of bubble is how many migrants accepted per year (1)

Some very brief insights:

There are four clear clusters in how the top countries approach immigration:

  • EU free-movement zone: Citizens from any EU country can move and settle permanently. These countries have high permanent migration but not all of it is for work — many movers come for family or retirement.

  • UK and former British colonies: Relatively balanced systems with a strong focus on skilled migration, but with lots of temporary work visas, student visas, and family-based pathways.

  • East Asia: Japan and Korea focus on temporary workers to support their aging demographics

  • Gulf + Russia: Autocracies who have a large amount of circular migration - the gulf from South Asia, and Russia from former Soviet neighbors.

Countries accepting of permanent migration tend to have less work-related immigration. Presumably one of the reasons is because when people want to move a place permanently, they want to bring their (potentially non-working) family.

East Asia takes in way more migrants than I had thought.

Next time I’ll double click into labor mobility specifically.

1. My data here comes from the OECD data explorer (permanent, temporary) for 2022. They . For Russia, the UAE and Saudi Arabia, data was harder to find, so take these with a grain of salt.

A timeline of human experience

Humanity has been around for a long time. About 300,000 years. For almost all of that time, people lived as hunter-gatherers or in tiny agricultural lived in settled, state-based societies as we do now.

But the world’s population was also very low for much of that time. Because there are about 8 billion of us today but fewer than one million people 100,000 years ago, each year of the modern era contains far more total “people-years” of lived experience.

A single calendar year in 2025 “contains” more human life than a year in 100,000 BCE, simply because today’s population is thousands of times larger.

One way to visualise history is to ask: at every point in time, how many total people-years had accumulated so far? (1)

The graphic divides history into ten equal “blocks” of experience: each block represents 170 billion people-years.

With an average population of roughly 600,000, it took nearly 300,000 years of prehistory to rack up the same 170 billion people-years that humanity has now accumulated in just the last 25 years.

By this estimate, 1300 is the half-way point of humanity. Half of human experience took place before 1300, and half took place afterwards.

This also lets answer some questions that may or may not be of interest:

  • What percent of human experience has been lived in the past 25 years? A whopping 10%

  • What percent of human experience has taken place since the Industrial Revolution? A little over 1/3.

  • What percent of human experience took place before the first human settlements (~6000 BCE)? Approximately 10%.

  • What percent of human experience has taken place since the birth of Jesus? Around 75% (2).

1. People-years are calculated by taking the world’s population, and multiplying by the number of years that population lived. So in a world with population 8 billion, every year that passes makes up 8 billion people years. In a world with a constant population of 100 million, it would take 80 years to create 8 billion people-years (100 million × 80 = 8 billion).

For you nerds out there, this is the integral under the population curve.

2. A couple other articles of interest:

Due to different methodologies and assumptions, some of them have answers that differ from mine by up to a factor of 2. For example, my analysis implies that about 1.7 trillion people-years have been lived, as opposed to 3.2 trillion from David Beiber. But what’s a factor of 2 among friends?

Why the wise old Greeks sound so wrong today

Lately I’ve been trying to get into the headspace of an ancient Greek (1).

Philosophers back then had some pretty funny notions:

  • Plato thought there was a world of ideas, where, for example, there was an ideal bed, of which all existing beds are just a copy.

  • Aristotle talked a lot about a thing’s “essence” as being core to its identity. For example, that a tree has some fundamental “tree-ness” property. If it loses its essence, it ceases to be a tree.

  • Parmenides believed that if we can think of a dead person, then that person must still exist somehow.

Outside of poetry, most people now don’t think there is some fundamental metaphysical difference between a bed and a table — both are just different configurations of atoms (2). And we don’t take the fact that we can think of someone as evidence that they exist.

So why do some of the smartest thinkers in antiquity get themselves into entire modes of thinking that now seem so wrong? Here’s how I’m coming to understand it:

Imagine you have not had any formal science or math education. But you are curious, you like thinking, and have the leisure to indulge yourself (3). How would you start trying to make sense of the world around you?

The winning move, in retrospect, was to restrict your questions to things that could be measured and tested. Don’t use concepts like “beauty”, “fitness”, or “essence” unless they are connected to a specific measurable quantity. And do this patiently, collecting tons of data over the course of lifetimes to understand which theories are right vs wrong (4). This is the approach that eventually gave us vaccines, airplanes, and the internet.

Now not only is all of this pretty hard. It’s also just not that obvious from the start how useful all this data collection will be.

The Ancient Greeks did not don the straightjacket of modern science. They investigated the physical world, but also metaphysics, ethics, politics, and music. They were interested in a thing’s purpose, not only causes and effects. And they described the relationships they observed or hypotheses using language, rather than just math.

This ancient approach to learning is wide-reaching, and poetic. The scientific approach to learning about the world is narrow and dry. But happens to be incredibly fruitful — allowing us live long lives, safe from disease, amidst the wonders of the modern world.

It took humanity hundreds of thousands of years to build the societal systems to pursue this method effectively. The great triumph of modern science is that we’ve tricked many of our smartest young people that the best use of their time is sitting in a lab taking detailed measurements and doing precise calculations. Their work is critical to all of us getting to live the (relatively) charmed lives that we do in the year 2025.

1. This came about because I’ve been reading A History of Western Philosophy by Bertrand Russell - a terrific read to give you a big-picture model of the entirety of western history.

2. People who know a bit more physics might think that rather than atoms, things are really made up of wavefunctions or fields or something. But people like that tend to be a confused bunch, and we’ll leave them to their own troubles for now. The point is that we all think of tables and beds as fundamentally made up of strictly physical things, with no metaphysical essence.

3. Most people in antiquity were, of course, illiterate, destitute, and/or enslaved. So to the extent they pondered the secrets of the universe, we don’t have any record as to what they thought.

4. A more detailed recipe to kick of a scientific revolution:

  • Only make claims that you can prove or disprove by observation and measurement. Then start taking down lots of observations and measurements.

  • Remember - you also need to track all these measurements super carefully. And paper is really expensive.

  • Oh, and to make sense of all the measurements you’re making, you will need more complex math than just addition and subtraction. So get on with inventing that.

  • And you can’t do all this by yourself. You also need to convince a bunch of other people to do the same. Even when most of the measurements aren’t useful, and the claims are wrong. And buy yet more paper so you all can correspond with each other.

  • And yet more: You should also convince rich people to invest lots of money into supporting you all while you do this, and help you to build the better and better gadgets you will need over time.

Whew, science is hard.

My brother is disabled, not differently abled

My brother has Down Syndrome. In my view, calling him “differently abled” is quite offensive.

1.      It is condescending. My brother is just quite literally unable to do basic things that most 22-year-olds can do. He can’t go do errands on his own, read chapter books, or clearly communicate his thoughts to people who don’t know him well.

2.      It supports a pernicious worldview. The only reason to be afraid of being blunt about my brother’s basic abilities is if you worry that lack of ability undermines his human dignity. But then why is his human dignity contingent on his ability to achieve tasks? (1)

To put it bluntly: To use the term “differently abled” to refer to my brother, is to imply that people with less ability inherently less valuable than more able individuals.

Down syndrome abortion rates should trouble us

Over the past 25 years, parents have largely stopped aborting girls just because they are girls. In 2000, 1.6M pregnancies were ended worldwide because parents would rather have boys than girls. “This year that number is likely to be 200,000—and it is still falling.”

This is terrific progress and should be celebrated. Because terminating a pregnancy on the basis of sex is wrong.

In the US and Europe we have another related problem - which is that people routinely terminate pregnancies where the unborn baby has Down syndrome.

The numbers here are pretty sobering. In the US, ~75% of pregnancies tested for Down syndrome get terminated. In Europe it is ~90% (1).

If you don’t think this is a problem, I want to convince you it is.

In the US and Europe, most of us believe people have equal worth, with equal rights to “life, liberty, and the pursuit of happiness”. If you agree, you should be skeptical about denying life – even to an as of yet unborn person - based on genetics.

We also generally value diversity - it’s good to have people with different worldviews and values, different appearances and different levels of ability because encountering human variety helps us become better. People with Down syndrome (DS) intimately force the people around them to see the world differently – and generally more positively. Do we want to get rid of those people?

But still, you might think the arguments from liberty and diversity perspective are outweighed by the costs to the person with DS and to their parents.

But on the whole, people with DS lead long and happy lives. Life expectancy is 50-60 years in the developed world (2). And 99% of people with DS report being happy with their lives.

Parents do face a burden in raising children with DS – a meta-study shows higher levels of stress and depressive symptoms. But they show similar levels of parenting reward to other parents. And many parents report being thrilled to have their child with DS. There is some evidence that at the time of making an abortion decision, parents are given a more-negative-than-accurate picture about what life is like for someone with DS.

So it is possible for parents of children with DS to thrive given the right circumstances. To the extent that DS creates extra burden for parents, we should take this as a problem to be solved, rather than looking to eliminate DS. Schools, healthcare, and societal expectations about what a good life look like all play a role here.

So on net - the costs of DS seem nonexistent from the perspective of people with Down syndrome, and the extra burden to parents seems manageable. But systematically we are ending pregnancies of people with Down syndrome.

A wealthy society that fundamentally values liberty and champions diversity cannot be satisfied when 70%+ of pregnancies with Down syndrome end up terminated.

I don’t think this is an easy one to solve – because it comes down to our fundamental values as society. But I may take a stab at it in another post – because why else would I be writing on the internet?

1. To translate that into a “missing people” number: Between Europe and the US there are about 12,000 “missing” people with Down Syndrome. 9,000 from Europe and 3,000 in the US.

2. Lower than average in rich countries. But still high by world historical standards – world life expectancy was <60 until 1979.

Going to California

I'm moving to San Francisco at the end of June to work at Lighthouse! Here are my goals living in SF for (at least) the next few years (1):

1. Do a great job at Lighthouse. High-skill immigration is great for the US - and the world. I’m excited to work on this with the terrific team at Lighthouse.

2. Host the best dinner parties. Quite modestly, my wife and I want to create a salon for builders, a gathering space for thoughtful people driving the future of business, technology, and society. Put less pretentiously, we want to hang out with fun and interesting people. Our apartment is called the Big Beautiful Sino-American Co-Prosperity Sphere, and those of you in the Bay Area can look forward to coming to its launch party in July (2).

3. Meet builders more generally. I’m inspired by entrepreneurs, by Progress Studies, and Effective Altruism. I’m excited to meet as many people as possible in these spaces to trade ideas and build together (3). If this sounds like you or anyone you know, let’s grab coffee!

4. Become great at using AI. My ability to use AI to get things done better and faster will determine how much I get done in my career. So it’s worth continuously investing time in learning to use the tools. Luckily, there’s no better place to be for this than the Bay Area.

Also I’m excited to be active in local and national politics. When I lived in Kenya, I didn’t have much scope for political activity. I’m not planning to run for governor or anything, but I’ll be an engaged citizen.

Perhaps most importantly: I’ve made a playlist of canonical California songs. Please add any I've missed.

1. I made a similar post when I moved to Nairobi, and found it extremely useful to have a public record of my motivations.

For keen readers tracking my evolving views on how to have positive impact in the world: I previously said that working in global development/global health was the best use of my time. Do I still believe this now that I am working in US high-skill immigration? I do still think global development is incredibly important, and am still working in it, though not as directly as I was before.

Here’s how I think about it:

  • Immigration drives development. It brings new opportunities - directly for the people who move. It drives the sending of remittances home. And it drives development in origin countries via brain gain.

    • Even if you are skeptical that high-skill immigration specifically has much development impact, it can still be instrumentally useful to creating more cross-spectrum immigration in the future. Because successful high-skill immigration can makes immigration overall more politically feasible.

    • In the future I will likely do a cost-benefit from an international development perspective of high-skill migration vs skill-trade immigration vs other types of development projects.

  • US excellence is important. I had previously underrated this. US technology, institutions, politics, and culture are really important for the world at large - including for global development (for starters - USAID matters!). By working in high-skill immigration in the US, I can contribute to making all of these better.

  • I have more faith in capitalism and commonsense morality to drive positive impact. I overestimated the impact I would have in my previous jobs, trying to optimize for global development impact. So taking a well-paying job in a field I think is important seems like a pretty good bet.

  • I’m also simply not optimizing for impact as much as I used to try to.

2. AKA “The Sphere”

3. I also intend to sharpen my own ideas by getting them out there. So expect more blog posts!

Half of the kids used to die

Half of the kids used to die.

Across societies with very different climates, cultures, and forms of governance, half of children died before the age of 15. People tried to stop children from dying, and they just failed.

Our World in Data

Things are much much better now. Worldwide childhood mortality is now 4%. In Niger it’s the worst, and it’s still only 15%.

15% of children dying is awful, but it’s way less awful than 48%. Prior to 1800, any country that achieved a child mortality rate of 15% would be seen as the absolute pinnacle of good governance and public health.

Half of children used to die, and now they don’t. If you were making a list today of the top 10 most important facts about the world, this would definitely be in it.

Previous generations have worked hard, and given us the gift of a world where only one in twenty-five children die.

It’s still too many! It’s up to us to give future generations a world where less than 0.5% of children die. It’s possible! It’s already the case in Finland, Norway, Japan, and Slovenia.

If you find yourself thinking that modern life is terrible, just remember that half of children used to die.

This post is essentially just my reflections on this much better post from Our World in Data.

No-regrets actions for the AI transformation

AI is changing the world and nobody knows what is going to happen.

Will we see an intelligence explosion or have a slow takeoff? Will AI lead to a new era of human flourishing, to autocracy, or to something much more mundane? How much work will get automated and how quickly?

All these things are subject to wide uncertainty. Smart people have widely differing opinions.

So, dear reader, what (if anything) should YOU do given that there is so much uncertainty?

I think there are a few no-regrets actions you can take if you - like me - you take the potential of AI seriously. Some actions that will be beneficial under a wide range of possible outcomes (1).

There are a few basic assumptions that underly my thinking:

  1. AI will transform society. This has happened before with technologies like agriculture, the steam engine, and the computer. It is already starting with AI.

  2. Nobody knows how the transformation will go. There is just a lot of uncertainty about what AI will be able to do, how well we will be able to control it,  how it will be deployed, and on what timelines.

  3. It might be bad. AI could enable terrorists to create powerful biological weapons. It could lead to mass unemployment. We could - wittingly or not - give AI systems access to powerful weapons that they decide to deploy.

  4. AI will take over a lot of work. AIs already do an OK job of writing copy, illustrating, writing code, and doing research. They will only get better.

  5. The AI transformation will occur under circumstances of competition. Both between nations as well as between companies.

Those are my starting points. I may write a future post on how you might think differently if you disagree with one or more of these starting points.

So now, let’s turn to the first thing that comes to mind in a situation like this. What’s going to happen to me?

How do I ensure the AI transformation goes well for myself?

If AI will take over a lot of work, what should you do to make sure that you will be ok if AI takes over a bunch of jobs?

There are four areas to focus here:

  • Use the AI. Become great at getting things done faster and better using AI. This blog post by Ethan Mollick has some great suggestions on how to get good. They boil down to “just use it a bunch and figure out what it’s good at.”

  • Know people and be likable. As more and more of the “thinking work” gets done by machines, a lot of the “people work” will still be left to humans. Your network will become more and more important. So be someone people know and like.

  • Manage. Know how to manage people well. And if relevant for your job, know how to manage AIs too.

  • Save more. To have a cushion against future shocks.

Now that your career is future-proof, and you have ample savings in the bank, let’s turn to what you can do to help the rest of us out.

How do I ensure the AI transformation goes well for the world?

Everyone should have at least one political cause of choice. If you don’t have one already, it is a great time to make AI your political cause of choice. Especially if you live in the US or China, since these are the two leading countries in the development of AI, and are both reasonably responsive to the concerns of their people.

But! Uncertainty. Is it better to Nationalize parts of AI development, or leave it largely in the hands of private companies? What kinds of regulations should be placed on AI development and deployment? To what extent should Americans be focused on getting the best models before China at all costs?

There are a couple principles that seem to make sense under a broad range of paths that AI development could take:

  1. Ensure transparency about what developers are training AI models to do. About what values are being instilled in the models. About what kind of safety measures are being programmed into them. The more these models influence the world, the more critical it is that they are subject to scrutiny by the widest possible number of stakeholders.

  2. Ensure adequate cybersecurity to ensure dangerous AI tools don’t get into the wrong hands.

Make your voice heard! The development of top AI models should happen transparently and securely.

It also seems valuable, even without the pressure of AI, to ensure US-China competition doesn’t turn violent. This is an area I am trying to learn much more about. If anyone has any concrete ideas on how we can ensure we don’t have war, let me know ;) (2)

Closing thoughts

AI is changing the world and nobody knows what is going to happen. The above is my best guess - right now - for how you can give yourself and the world the best chances of success during the AI transformation.

What do you think?

  1. None of my thinking in this post is original. And this is very much a work in progress capturing my thinking at this point in time. I would love for you, dear reader, to tell me what you think. Also note that this advice - especially the political advice - will make the most sense for white collar Americans.

  2. My vague thinking here is: It’s inevitable that the US and China will compete. This is what global powers do. But the more we can channel our competition into productive ends, the better. For example, you can imagine countries focusing their competition on achieving soft power dominance by providing paths for economic development, winning at sports, and exporting great culture rather than fighting wars.

Kenya lessons and new ideals

When I moved to Kenya, I boasted to have two core ideals. Now that I’m moving back to the US, I’ve revisited them.

Core Ideal 1: I ought to push myself to help people as much as I can.

I’ve moderated on this.

Fine fine fine! Older, wiser people were right. I’m not as radical as I thought I was. I no longer foresee a life of living in tiny rooms, on beans, trying to engineer my personality around having as much positive impact as I can.

I still won’t be complacent with a career that does only an ok amount of good. I’m still strongly opposed to [hedonism](https://www.merriam-webster.com/dictionary/hedonism?). I have ambition to do great things in my career.

Concretely helping others is still one of my priorities. But it is no longer my only priority.

And to be frank, it’s not clear that obsessing over my impact has even done me much good. At both BCG Nairobi and Kapu I had less impact than I thought I would at the outset. There was definitely impact-motivated wishful thinking on my part in both these career decisions.

I can’t know the counterfactual, and I deliberately did things that were higher risk But there’s a decent case to be made (my wife has made it) that I have overthought things and would have had more impact by just working in the US at a job that made a lot of money, and donating a lot.

So gone are the days of looking at my calendar and pretending that all my time is exclusively optimized for having as much impact as I can.

Core Ideal 2: I ought to look for opportunities where I will be doing work that would otherwise not be done.

I 100% still agree.

Over the course of 3 years helping to build a company, it's become clear to me how many problems exist only because nobody has built solutions to them.

More generally: Much of our world was built by people. Companies. Relationships. Social norms. Works of art.

It's up to us to continue the work of those who went before. To build on what has already been built. And - when needed - to tear down and build anew.

So I plan to build things. Create some products. Start a company or two. Write music. Create community. Start my own family.

So: Luke’s New and Improved Ideals as I move back to the US:

  1. My top priority is my wife (and future children).

  2. I build things.

  3. I ought to push myself to help others a lot.

Let’s see how they stand up in 4 years time.