Monopoly's Old 10% Tax Choice and Your Investment Fees

For decades, the Income Tax square on the American Monopoly board gave you a choice: pay a flat $200, or pay 10 percent of your total worth. The catch sat in the small print of the rules. You had to pick before you counted. No adding up your cash, no tallying property cards, no peeking at the houses. You guessed which number was smaller, committed, and only then did the math.

Hasbro dropped the percentage option around 2008, and the square now just takes $200. I still think the old rule was one of the best money tests ever printed on cardboard, because it asks the exact question most investors never ask about their own accounts. Is a percentage fee or a flat fee cheaper for me, right now, at my actual balance? Almost nobody can answer without looking it up, and plenty of people cannot answer even after looking.

The $2,000 break-even hiding in the square

The arithmetic is simple once you see it. Ten percent equals $200 when total worth is exactly $2,000. Below that, the percentage wins. Above it, the flat fee wins. Every player starts with $1,500 in cash, so on an early lap the 10 percent option almost always costs less.

The trouble is that total worth in the old rules counted more than cash. It included the printed price of every property you owned, mortgaged or not, plus what you paid for your buildings. That is where people went wrong. Picture someone holding Boardwalk ($400) and Park Place ($350) with two houses on each, at $200 per house on the dark blues. That is $750 in deeds and $800 in buildings, or $1,550, before counting a single bill. Add $600 in cash and the total is $2,150. Ten percent is $215. The player who felt cash-poor, staring at six hundred dollars in their hand, would choose the percentage and overpay by $15.

Fifteen dollars of play money is nothing. The habit behind it is expensive. People judge their worth by the liquid number they can see, and they forget the assets that quietly grew in the background.

Why my own guess was wrong for six years

I opened my first index fund account at twenty four and have logged every contribution since, so you would think I knew my balance. I knew my contributions. I did not know my total. For years I carried a figure in my head that ran roughly 20 percent below reality, because I ignored a rollover IRA from an old job and treated my workplace plan as somehow separate from my investments.

That gap mattered the year I sat down with a fee-only planner who charged a percentage of assets. I had assumed the percentage would be small because my balance was small. My balance was not small anymore. I was making the Boardwalk mistake with real money.

The planner, to his credit, raised it himself. He asked me to list every account before he quoted anything. When the list was done, a flat annual retainer from a different planner came out cheaper by a few hundred dollars a year. I switched. I am not saying percentage advisers are bad, only that I had no idea which side of the break-even line I stood on until I counted.

Flat versus percentage at real balances

The table below uses two common fee shapes. One is an advisory fee of 1 percent of assets per year, which is still the figure many firms quote as standard. The other is a flat retainer of $2,000 per year, which sits inside the range I have seen advice-only planners charge, though prices vary a lot by city and by how much work you need.

The break-even in this case is $200,000, which is the Monopoly square scaled up by a hundred. Below it, a percentage feels gentle. Above it, the percentage keeps climbing while the retainer stays put, and the gap compounds because every dollar paid in fees is a dollar that stops growing.

A second percentage hides inside most portfolios: the fund expense ratio. A broad index fund might charge 0.03 or 0.04 percent. An actively managed fund in the same account might charge 0.75 percent. On $200,000 that difference is roughly $1,400 a year, and nobody sends you a bill for it. It comes out of the fund quietly, which is the closest thing in real life to the old tax square paying itself while you were not watching.

The common advice I would push back on

You will often read that you should "always avoid percentage fees." I do not agree. If you have $40,000 invested and you need someone to look over your whole financial picture once, a percentage fee on a small account can cost less than any flat retainer worth hiring. The game agreed with this, too. On your first lap around the board, the 10 percent option was the right call nearly every time.

The better rule is the one Monopoly enforced by accident: know your total before you agree to any fee that depends on it. A percentage fee is fine at one balance and wasteful at another, and the line between them moves every year as you contribute and as markets move. The fee you chose at thirty may be the wrong fee at forty, even if nothing about the adviser changed.

The rule asked you to guess your worth before you counted it, which is exactly how most people pick an investment fee.

There is also a limit to what I can tell you. I do not know whether your adviser earns their fee in ways that do not show up in a table, such as stopping you from selling in a panic. That can be worth more than any gap above. I only know it is worth putting a number on it instead of assuming.

Count before you choose, this week

Here is a small exercise that takes about forty minutes. Write down a guess of your total invested balance before you open any app. Then log into every account you have, including old workplace plans, any IRA, a health savings account invested in funds, and a taxable brokerage account if you have one. If you are not sure what a taxable account even is, our walk through of how a brokerage account works covers it.

Compare the real total to your guess. In my experience, most people miss by more than 10 percent, and nearly always on the low side. Then find two numbers on your statements: any advisory fee, written as a percentage or a dollar figure, and the expense ratio of each fund you hold. Multiply each percentage by the real balance. If an expense ratio looks high, a plain explanation of what index funds charge and why gives you a baseline to compare against.

You may decide to change nothing, which is fine. The point is to make the choice the way the old Income Tax square should have been played, with the total in front of you. More of our board game and video game money pieces sit in the games section, if you like learning this stuff from a playing table.