I just came across this post by Paul Graham called, "modeling a wealth tax." It's from last year, but it recently resurfaced. In it, he paints a scenario. Let's say you're a successful entrepreneur in your twenties (i.e. you make some money) and then you live for another 60 years. How much of your stock would the government take with various wealth taxes?

With a 1% wealth tax, it means that you would get to keep 99% of your stock each year. But assuming the wealth tax gets applied every year, you would be left with 0.99^60, which equals 0.547. Put more simply, a 1% wealth tax would mean that over the course of the 60 years after you built your company, you would be giving the government 45% of your stock.

How did this number get so big?

The reason wealth taxes have such dramatic effects is that they're applied over and over to the same money. Income tax happens every year, but only to that year's income. Whereas if you live for 60 years after acquiring some asset, a wealth tax will tax that same asset 60 times. A wealth tax compounds.

Of course, Paul also points out that giving away a portion of your assets each year doesn't necessarily mean that you're becoming net poorer, so long as your assets are increasing in value by more than the wealth tax rate.

Still, these are massive numbers. A 2% wealth tax would translate, over this same 60 year time period, into the government taking 70% of your stock. A 5% wealth tax works out to 95%. For more on this, check out Paul Graham's post.

Global household wealth is currently estimated at about $360 trillion, according to Credit Suisse's 2019 Global Wealth Report. This represents an increase of about $9 trillion (~2.6%) from 2018-2019.

Over the last decade, much of this growth in household wealth has come from two countries: the United States and China. 40% of the world's US dollar millionaires reside in the United States, and China now has the second highest number of dollar millionaires. (If there are any curious Canadians reading this, Canada represents 3% of the world's total.)

The number of ultra-high-net-worth individuals -- individuals with a net worth greater than $50 million -- exhibits a similar pecking order. The US is by far the most dominant.

Of course, dollar millionaires represent a small percentage of the world's total population. Credit Suisse estimates that there are about 5.1 billion adults in the world. About 56.6% have a net worth under $10,000 and about 0.9% (okay, 1%) are millionaires. This 1% controls/owns about 44% of global wealth. Thinking back to figure 7 (above), consider this math: 50% of the world's millionaires are now in the US and China.

Fluctuations do happen, however. Australia lost some 124,000 millionaires last year largely because of a (-6%) drop in home prices, which tends to correlate pretty closely to the real asset part of household balance sheets. Australia shed about $443 billion in household wealth since 2018, making it the biggest loser in Credit Suisse's report.

The other thing that you may find interesting from this report is the wealth/GDP ratio that they use. Household wealth and GDP tend to correlate. But the ratio of wealth to GDP also has a tendency to increase as a country develops. This makes sense because things like the rule of law and access to capital tend to increase people's willingness to invest/borrow. But in developed countries, it could also be a signal for asset inflation.

If you'd like to download a PDF of the full wealth report, click here.

Note: Credit Suisse's definition of household wealth is your typical net worth calculation: assets (financial assets and real assets) minus liabilities. For most people, the real asset part is principally housing.

Charts: Credit Suisse Global Wealth Report 2019

Bloomberg recently came up with a new index to define the distribution of wealth across adults in the world. They're calling it your "net worth number" and the scale ranges from -2 to 11. Sadly, because the gap is so significant between the rich and the poor, it is based on a logarithmic or non-linear scale. Here's how they break it down:

Logarithms of negative numbers aren't a thing, and so, technically, if your liabilities exceed your assets (i.e. you have a negative net worth) you shouldn't appear on this index. But Bloomberg has added those people -- which could be students with debt, after all -- into the -2 category of their scale. These are people with a penny to their name.

Now, the number of adults in each bracket is purely an estimate. If you look at different sources, you will end up with different numbers. Bloomberg believes that there are 2,800 adult billionaires in the world (numbers 9 to 11); whereas Credit Suisse's estimate is about 1,600. (I wonder if it's easier to estimate the number of billionaires or the number of -2's.)

Still, it is eye-opening to see where most adults sit (at number 3) and how bottom heavy this index is.