Most of us would consider ourselves rational consumers. We buy what we need. We try not to overspend. We save where we can. But in many ways, 2012 was the year of the irrational consumer. Just take a look at JCPenney’s epic rebranding fail. Late last year, Apple’s Ron Johnson became the department-store chain’s new CEO and soon introduced a “fair and square” pricing and marketing strategy in which the retailer abandoned discounts, rid itself of coupons and simplified prices. It flopped. It turns out that we like rushing to stores for weekly promotions and markdowns — even though we know the sale prices are being discounted from inflated original prices. And we like prices that end in .99 because it looks less expensive. Similarly, consumers have taken to layaway in a big way after big-box stores brought it back following a hiatus of several years. Why is layaway irrational? First, it adds fees to purchases that often wind up costing consumers more than if those items were charged to a credit card with a reasonable interest rate. The purpose of layaway is to help people save for items over time. But you don’t need a program (or the fees that go with it) to do that. All you really need is a piggy bank.