Milton Friedman understood that the way we spend money changes our incentives.

Comment “Friedman” and we’ll send you an article on the topic. When we spend our own money on ourselves, we care about both price and quality. When we spend someone else’s money on ourselves, the pressure to economize weakens. And when we spend someone else’s money on someone else, both disciplines largely disappear. That final case resembles much government spending. Public officials allocate resources they did not personally earn to beneficiaries whose preferences they may only imperfectly understand. Even with good intentions, the incentives to minimize costs and maximize value are weaker than in voluntary exchange. This helps explain why public programs can become expensive, wasteful, and resistant to correction.