Articles: Modeling

The 4% retirement rule suggests you can safely withdraw 4% of your portfolio in year one of retirement, then adjust that amount for inflation each year for 30 years without running out of money. But how does this actually play out year by year? This article builds a complete Excel model to find out, exploring three different approaches, from classic row-by-row formulas to modern dynamic arrays to a single formula that generates the entire 30-year schedule. These models are fully functional, so you can play with the inputs and see how things work yourself.

In this article, we take a look at a simple model that calculates the time that could be saved by doing a task or activity with more skill. The goal is to visualize whether it makes sense to invest in getting better at a skill.

In this article, we build a model using the seldom-seen Data Table to visualize at what point an Adwords campaign becomes profitable.