Working long hours as a matter of course is really bad for you, and your company. There's of course the personal cost you carry, being stressed and overworked

Working long hours as a matter of course is really bad for you, and your company. There's of course the personal cost you carry, being stressed and overworked constantly affects your health and happyness adversely. Productivity also suffers, intraday productivity drops off sharply after more than 4 hours, and you should really stop after more than 8, especially if you're a knowledge worker. Over long periods of working long hours, your productivity becomes permanently depressed, where you might start your day already with only 1/3rd of the productivity a non overworked, rested you would have, which is basically worse then what it would be if a rested and non overworked you would do after a single 12 hour day. If you let your employees work long hours continously, you are basically accepting that for the price you hired them, you will only get about half to a quarter of an employee. That's heck of an expensive way to run a business.