Direct trading of permits would provide a way to reconcile the values of people bent on whale conservation and hunting, respectively. The authors calculate that total profits from commercial whaling are no more than $31m per year, whereas the spending by major anti-whaling NGOs is already around $25m. Under a permit system, the theory goes, the latter would pay whaling fleets not to hunt. With earnings per whale ranging from $13,000 (for minke whales) to $85,000 (for fin whales), the conservationists' goal looks affordable.