Sublime

Let us start by introducing a variable, r(t), which denotes the accumulation of the net quantity of y(t) over time t. For example, if y(t) stands for wages, then r(t) becomes monetary wealth, but we should think of r(t) more generally as resources that can be grown in time and used in turn (“reinvested”) to generate more y(

If the exam wants to see you sweat—and, trust me, it does—it will say the return was 10% over 18 months. Luckily, 18 months is 1.5 years, so divide the 10% by 1.5, and you’ll see that the annualized rate of return is 6.7%. Or, divide the 10% by 18 and then multiply that by 12.

linear time—time as a unique (and usually progressing) story with an absolute beginning and an absolute end.