Systems that assume you will be irrational

You now have the full set: a discount curve that is steep near the present, losses that outweigh gains, a copying instinct, a self-assessment with no feedback, a search that finds what it went looking for, and a comparison group you did not choose.

Eight lessons of this track have described those as things done to people. For the next ten minutes you are on the other side of the table, because the fastest way to see a mechanism clearly is to be asked to use it.

Then we turn it around, and the turning around is the actual lesson.

Build the thing

What would have stopped you

Now the useful question. For the option you picked, what would a customer have had to do to be immune?

Not "know about the bias". Knowing about present bias does not make the thirty-day charge feel present. Knowing about the decoy tier does not stop the middle option looking reasonable, and knowing about loyalty points does not make an expiring balance feel like nothing.

Four grades of system

The same intention can be built four ways, and they are not close in how often they survive contact with a bad month.

Intention. You have decided to do the thing. It requires an act every time and there is nothing behind it but you. This is the grade almost every financial plan is written at.

Reminder. Something prompts you at the right moment. Better, because it fixes forgetting, and it still asks for the act.

Default. The thing happens unless stopped. The act is now required to not do it, which puts the ratchet and the loss asymmetry on your side for once.

Constraint. Doing otherwise is genuinely awkward or costly — money that is somewhere it takes three days to reach, a commitment somebody else is holding you to. Strongest, and it costs you flexibility, which is a real price and not always worth paying.

The uncomfortable symmetry

The mechanisms in the first half of this lesson and the systems in the second half are the same mechanisms.

A free trial that converts by default and an automatic transfer that saves by default are one design pattern, pointed in two directions. Points that expire and a constraint you would lose money by breaking are the same use of loss aversion. The seller who removes a decision from you and the arrangement that removes a decision from your future self are doing identical work.

That symmetry is worth sitting with rather than resolving. It means these techniques are not good or bad in themselves, and the only question that separates them is who chose the default and whose interest it serves. When the answer is "somebody selling to me, in theirs", it is worth a second look. When the answer is "me, in advance, in mine", it is the strongest tool in the course.