By Adrian Moore, includes “…The run-up in debt over the past 10 years is mostly due to the plan’s investment returns averaging about 1 percent below expectations. … The run-up in debt over the past 10 years is mostly due to the plan’s investment returns averaging about 1 percent below expectations. … Third, the state uses a method of calculating the value of promised retirement benefits that increases risk and makes the real debt larger than what is assumed. …”