by MARIJKE RIJSBERMAN (FAIR Money; Coursera) Marietta is 61 years old. She takes care of her adult son (unemployed) and her daughter-in-law (disabled), both of whom live with her in a simple 3-bedroom house on the wrong side of the freeway. Her rent is sky-high, because in Silicon Valley rents are crazy on both sides of the freeway. Marietta also contributes to her mother’s care. She is trying to keep up payments and insurance on three cars, one of which is currently non-operational, and she has title loans on the other two. And she has a set of payday loans outstanding. Small-dollar subprime loans like the ones Marietta has are marketed only to those who have few choices. Payday loans are meant to tide you over until your next paycheck, so they run at most for a period of two weeks. In California, you can borrow up to $300, but a fee of $45 is immediately withheld, so you end up with $255 in hand. You owe the full $300 in two weeks or less. If you can’t pay it back in full, you “roll it over.” That is, you get a new...