Sunk Cost is a cost that was already incurred and thus can not be recovered. Sunk costs differs from other, future costs that a business may deal with, such as catalog costs or R&D expenses, because it has already happened. Sunk costs usually are independent of any event that could occur in the foreseeable future. In economics sunk costs are cost that was already incurred and can not be recovered. Sunk costs are now and again contrasted with future costs, which are future costs that may be incurred or changed if an activity is taken.