Zero-based

I first saw "zero-based budgeting" in some leisurely weekend reading on private equity firms (I know, party animal comin' through). The idea is to start each annual budgeting process "from zero" and justify all expenses from scratch instead of anchoring on existing spend. "How much should we spend on X," instead of "cut 5% off X this year"

This is a useful framework for other contexts:

• Every day you stay at a job is a decision to take that job, knowing what you know that day.
• Every day you hold an investment position is a decision to buy on that day's price and fundamentals.
• Every day you spend in a relationship, friendship, partnership is a decision to... you get the idea.

Of course, it's not perfect. Real life has pesky things like transaction costs, but that's entirely the point. Starting from zero is an offset against complacency and over-indexing on sunk costs.