Shah Waliullah in Hujjat Allah Ul Balighah writes that exchange is of different kinds. Goods for goods or goods for services. There are people with surplus funds and some with deficiency of funds. This requires transfer of resources for need fulfillment without counter value as in Zakat and Sadaqat.
Money supply can be increased out of thin air, but the non-renewable resources once exhausted cannot be brought back. Remarkably, the importance of ecology is not learnt even after repeated unsuccessful expeditions in space to search life supporting environment. An illuminating, enlightening and informative book cannot be valued just by measuring the cost of pages, printing and binding.
Islamic Economics Project 