Give yourself a week to do a task, it will take a week-but give yourself two days, and it will take two days. This phenomenon is known as Parkinson’s Law, which states: “Work expands so as to fill the time available for its completion.” The same is true of spending and money.
When budgets expand
The minute you get a raise or even some birthday money, enter Parkinson’s Law: Your spending expands to consumethe additional cash
Here are three ways to regain control over your cashflow:
Shrink your numbers: If you give yourself $500 to spend on groceries each month, you will. Lower that limit and you'll surprise yourself by spending less.
Be skeptical about “needs”: If you get a $200 raise, don't justify spending it because you "neeeeed" a bigger car, new dishwasher.
Keep percentages steady. I strive toward the 50/30/20 Budget. Because these budgets rely on percentages, as my earnings go up, my savings and spending also increase-but they remain in balance.