However, CVM is not a perfect method and has some problems, of which hypothetical bias problem is so serious that motivates research to develop techniques that either eliminate or adjust for it.

• 但随着领域的扩展和方法的改进，CVM存在的弱点也逐渐被指出，其中一个问题就是消费者会高估产品的经济价值，使得评估结果存在假设偏差。