The term availability heuristic refers to the natural tendency to place too much emphasis on simple rules that readily come to mind or are easily imagined when making decisions. For example, imagining the possibility of an early death is much easier for most people than envisioning the possibility of living to 105. When it comes to annuities, this presents a challenge because people have a tendency to underweight longevity risk and overweight the possibility of dying just after an annuity is purchased.