Rotisserie chickens have been around for a while. I used to bypass them and roast my own, until I noticed something: The rotisserie chickens were actually cheaper than buying and roasting my own. 
 
 Cat Vasko noticed the same thing and decided to figure out why. The answer makes a surprising amount of sense: Grocery stores make them out of unsold chicken that is about to pass its expiration date. It's an elegant way to make a profit out of food that would otherwise be a net loss. And it's not just chicken -- according to Vasko, the ever-expanding prepared-foods section of the supermarket uses up all sorts of unsold produce and meat. It is, as she says, a bit like hunter-gatherers using every inch of the animal. 
 
 This is the sort of thing that no one talks about when they talk about innovation --and yet, it's a major way in which our economy has become more efficient over the last few decades. Reducing spoilage means grocery stores can sell us raw chickens at lower prices -- and that we can get fresh, delicious prepared food at even lower prices. It's a win for the grocer and the consumer. 
 
 So the next time you hear someone talk about the innovation economy, don't just think of Facebook or Google. The folks who spit-roast chickens, streamline factory production, or think up any of a million ways to save a little money here and there are just as important in improving our standard of living. Especially when it's five minutes to 7 and you still haven't made anything for dinner. 
 
 This column does not necessarily reflect the opinion of Bloomberg View's editorial board or Bloomberg LP, its owners and investors. ||||| A couple of years ago, I got it into my head that I wanted to roast a whole chicken, just because. I wandered around my local Ralphs for a few minutes looking for poultry that hadn't already been turned into individually shrink-wrapped meat units before asking for help. The gentleman I flagged down blinked a few times at my question. "Um," he answered finally. "You know we have chickens for sale up at the front of the store that have already been cooked, right?" 
 
 I bought the raw chicken anyway. I took it home, rubbed it in butter and herbs, shoved a lemon half up its butt, and roasted it low and slow for the majority of the day. It turned out okay. For all the work it took, it certainly wasn't notably better than a store-bought rotisserie chicken, and with the other ingredients factored in, it cost significantly more. Right now, an uncooked chicken at Ralphs runs you $9.87, but a rotisserie chicken is $6.99; at Gelson's, you'll pay $8.99 for a cooked chicken or $12.67 for the raw version; and at that beloved emporium of insanity Whole Foods, a rotisserie chicken is $8.99, while a whole chicken from the butcher counter is $12.79 ... per pound. 
 
 In retrospect, it's not hard to understand why the fellow at Ralphs thought I was weird. But in most cases, preparing meals from scratch is significantly cheaper than buying them pre-made. What makes rotisserie chickens the exception? 
 
 Grocery Store Economics 
 
 The answer lies in the curious economics of the full-service supermarket. For instance, the Gelson's by me offers, among other amenities, a hot bar, a salad bar, a bakery, a gelateria, a full-service deli and an olive bar, because we live in L.A. so why not. But how can it afford to put out all of this food fresh every day? 
 
 It can't. Neither can Ralphs. Even Whole Foods' notoriously inflated prices don't offset that level of production. Instead, much like hunters who strive to use every part of the animal, grocery stores attempt to sell every modicum of fresh food they stock. Produce past its prime is chopped up for the salad bar; meat that's overdue for sale is cooked up and sold hot. Some mega-grocers like Costco have dedicated rotisserie chicken programs, but employees report that standard supermarkets routinely pop unsold chickens from the butcher into the ol' rotisserie oven. 
 
 Though supermarkets are loath to admit as much, likely for fear of turning off the squeamish, the former CEO of Trader Joe's cheerfully confirmed in a recent interview that meat and produce are recycled into prepared foods. And the vendor of one of the leading commercial rotisserie ovens offers, as a complement to its wares, "culinary support" that, among other things, aims to "develop programs to minimize food shrinkage and waste" and "improve production planning to optimize the amount of fresh food that is available during both peak and down times." 
 
 Rotisserie chickens aren't even the end of the line. When unsold, fresh meats, fruits and veggies that have passed their sell-by points can be "cooked up for in-store deli and salad counters before they spoil," per no less a source than a consultant to the supermarket industry. 
 
 Thinking back with horror on all the times you picked up a prepared meal on the way home from a long day of work, then demolished it within ten minutes of walking through the door? Don't panic just yet. 
 
 Safe as Milk 
 
 It's worth noting, first of all, that sell-by, use-by and best-by dates were never intended as indicators of food safety, but rather as estimates of food quality. The USDA itself says that food product dating is intended to "help the purchaser to know the time limit to purchase or use the product at its best quality. It is not a safety date." 
 
 Further, it's pretty well documented that these estimates are no substitute for boring old human discretion. Sites like StillTasty.com aim to help consumers get the most out of their groceries by educating them on the real shelf lives of thousands of foods as well as ways to ascertain quality that have nothing to do with the numbers stamped on the package. And a recent report from Harvard's Food Law and Policy Clinic suggests that because date labels are wildly inaccurate a lot of the time, they're pretty much directly responsible for 60 billion pounds of wasted food every year. Even more disturbingly (especially for we Californians), the report estimates that 25% of the fresh water used in the US is "squandered on the production of wasted food." Awesome. 
 
 In fact, in spite of their creative uses of items that have passed their sell-by dates, grocery stores are still being conservative enough when it comes to food safety to waste plenty of usable meat and produce -- around $900 million in inventory annually, according to a 2001 study. And as the Harvard report points out, major retailers aren't generally wont to take a loss, meaning their waste "ultimately could be a cost born by consumers in the price of goods." 
 
 So not only do you have nothing to fear from that grocery store rotisserie chicken, you could actually be doing a triple good deed by purchasing it -- making your life easier, keeping prices down for your fellow shoppers, and helping the environment.
– Those who like chicken might have noticed a seemingly weird quirk in the grocery store: It's generally cheaper to buy a fully cooked rotisserie chicken than to buy a raw chicken and prepare it yourself at home, writes Megan McArdle at Bloomberg View. Cooking food yourself is typically cheaper, so why the exception here? McArdle cites a post at KCET that explains what's going on: Supermarkets use chickens that are about to hit their sell-by expiration date for those rotisseries. In fact, they do it not just with chicken but with many of the offerings in the prepared-food department. Underhanded? No, writes McArdle. It's actually kind of brilliant. Instead of taking a loss on the still-fine food, the stores cook it up and serve it hot. "This is the sort of thing that no one talks about when they talk about innovation—and yet, it’s a major way in which our economy has become more efficient over the last few decades," she writes. The practice benefits both the store and the consumer, and it reduces spoilage to boot. Click for her full post.