I just saw this article on Vanguard, it's a good read and worth further investigation. Here is the quote that caught my eye skimming it...

First, there's Amos Miller, a 45-year-old Amish farmer, who managed to save $400,000 for a down payment on a farm. Amos and his wife Fern managed to save that much while raising their family—of 14 children.

Next, consider the experience of Bill O'Brien, a local banker who has issued $225 million in loans (mainly for real estate purchases) to Amish families over a 20-year career. How many of these loans have resulted in a loss for the bank? Zero. And he can count on one hand the number of Amish borrowers who have ever asked him for a loan extension or modification.