revision preference src: However, the market mechanism often can not optimize for public goods, owing to problems such as the tragedy of the commons. Modern highways have been good for economic development, but it has taken government planning and allocation to bring them into existence. <SEP> tgt: However, the market mechanism often can not optimize for public goods, owing to problems such as the tragedy of the commons. For example, modern highways have been good for economic development, but it has taken government planning and allocation to bring them into existence.