Could someone explain the reason for usury being forbidden in Islam?
Some background: I have some money, which I could take advantage of right now. Giving up this money, in the form of a loan would surely mean an opportunity cost for me, as time might not be entirely homogeneous for all. Moreover, I could simply place the money (safely) in my pocket. In this case, I am accepting a certain risk of default on part of the lender, which at most might eliminate the money, and at least cause some inconveniences to recover the money. If these basic costs are not covered by the loan, no incentive remains for lending money, which at large would slowdown the economy and disable wealth shift from the wealthier middle-age population to the more-in-need youth.