liability 类型例题

关于，time和demand deposit，先看以下原版书中关于life insurance的说法，他把寿险他也化到了Type II:

Although the timing of the insured's death is unknown, a life insurance company holding a large portfolio of policies can benefit from the “law of large numbers.” This means that the insurance company can use actuarial science to predict, on average, the amount of total liabilities due for each year and so can gain a very good sense of the amount of cash flow it will have to pay out in a given year.

所以，即便是liability中的个体的死亡时间并不确定，但是作为liability的一个整体，赔付的金额是确定的。作为time和demand deposit，把他们当做一大类liability，站在银行的角度，从一开始就明确知道整个负债的金额，这个数额是确定性的。

关于contigent onvertible bonds，他是liability、还是equity要看特定事项是否发生触发行权；首先将来是不是liability都不能确定；且他的未来现金流会有多种情景，哪种情景会发生也不知道；一旦转股，Coupon和面值也不用还了；所以负债数额并不是一开始就明确确定的。