Yes, doubling your income and maintaining your lifestyle would make a huge difference. In many cases such an extreme bump isn't reasonably available.
I believe GP was more referring to the rough rule of thumb is to have 25x your annual expenses by the time you retire. +5k income versus -5k expenses, you're better off cutting your expenses. By cutting expenses, the target drops by 25xExpensesCut, and you're throwing an extra ExpensesCut towards savings, helping on both sides of the equation. Going from spending 95% of savings to 90% makes a huge difference on the timeline, but 50% to 45% is much more modest since the timeline for compounding growth is so much shorter.
Using 70k income, 50k expenses, and a 5% return, this would take about 30 years. [0]
75k income, 50k expenses goes to 25.2 years [1]
70k income, 45k expenses goes to 24 years [2]
150k income, 50k expenses goes to 10.6 years [3]
Another detail often forgotten about, salary is stated before taxes, spending is almost always after taxes.
That further increases the power of decreasing expenses.
All good points. The original article has a few things that are oversimplified I think, which is why I criticize it a bit. For example, if you go from a country in the EU to San Francisco, you're going to earn way more but spend way more too. But if you plan on going back to the EU when you retire, this won't matter much because your living expenses will drop.
I don't know how hard is doubling your income in general, but I don't know if it's always harder than dividing by two your expenses. The thing is that by focusing on earning more, you will end up with more money, and at that point you can always cut back expenses. While if you focus on cutting back expenses, you will end up with less money.
I believe GP was more referring to the rough rule of thumb is to have 25x your annual expenses by the time you retire. +5k income versus -5k expenses, you're better off cutting your expenses. By cutting expenses, the target drops by 25xExpensesCut, and you're throwing an extra ExpensesCut towards savings, helping on both sides of the equation. Going from spending 95% of savings to 90% makes a huge difference on the timeline, but 50% to 45% is much more modest since the timeline for compounding growth is so much shorter.
Using 70k income, 50k expenses, and a 5% return, this would take about 30 years. [0]
75k income, 50k expenses goes to 25.2 years [1]
70k income, 45k expenses goes to 24 years [2]
150k income, 50k expenses goes to 10.6 years [3]
Another detail often forgotten about, salary is stated before taxes, spending is almost always after taxes. That further increases the power of decreasing expenses.
[0] https://networthify.com/calculator/earlyretirement?income=70...
[1] https://networthify.com/calculator/earlyretirement?income=75...
[2] https://networthify.com/calculator/earlyretirement?income=70...
[3] https://networthify.com/calculator/earlyretirement?income=15...*