In the earlier times mentioned by Brooks, many families were farmers with incomes that fluctuated greatly because of changes in the weather, and because of pests and diseases.
In earlier time, families had to save to provide for their old age consumption since social security and company pensions were non-existent.
A few other factors have contributed to the borrowing boom in recent decades.
Families had little opportunity to get commercial credit to help tide them over the bad times.
They had either to borrow from relatives, accumulate assets that could protect them against future risks, or suffer much during the bad times.
They would have saved less and welcomed credit cards, mortgages, and harvest loans as more effective ways to adjust to these risks.
Until the past 50 years, children from well off families had a large advantage in going to college because their studies were in large measure financed by their parents.
Obviously, some individuals borrow too much, and get caught in a spiral of high interest rate payments, bankruptcy, and insufficient assets as they age.
Nevertheless, on the whole the growth of credit instruments available to consumers has been a positive development that helps finance investments in education and other human capital, and produces a more optimal consumption profile over the lifecycle.
This has clearly been the case with the expansion in consumer credit instruments, but the benefits from this expansion seem to have far outweighed the costs.