 Emphasizing its informational component, some writers stress the positive value of advertising. Markets function efficiently only when certain conditions are met. One of these conditions is perfect information. Minimally, consumers have to understand the features of the products for sale. While this condition will never be fully met, advertising can help to ensure that it is met to a greater degree (Heath 2014). Another value that can be promoted through advertising is autonomy. People have certain needs and desires—e.g., to eat healthy food, to drive a safe car—which their choices as consumers help them to satisfy. Their choices are more likely to satisfy their needs and desires if they have information about what is for sale, which advertising can provide (Goldman 1984).