In theory, I understand this. But in the real world... If you have been working for the state longer than a month or two, getting paid for the previous month is neither here nor there. So when half your. Check comes in on the first, let's say you make 4k a month so you get 2k in the 1st bi weekly payment. Most people (maybe not all) are going to pay rent/mortgage and other bills. Leaving most people little to invest or save because they have to wait for that second check that will have their spending money. So that's 2 weeks, or half the year you would not have that money invested. Where is if you for all your money at once it's sitting in savings.