How Many Cups of Coffee Should You Buy to Day?

Economists call it the rational rule, and it says, if something's worth doing, keep doing it until the marginal benefit is equal to the marginal cost. Any time your marginal benefits are greater than your marginal costs, you know that's going to make you better off. So this sounds like an idea i can apply to just about anything. How many cups of coffee to buy, how many baresters to hire, how many hours to work and so on. They're all how many questions. And much of economics is about one simple answer, keep doingIt until the marginalbenefit isequal to themarginal cost.