A concept talked about at length in the book is the idea of long-term average returns and how many pension actuaries rely on them to determine funding. Mr. Waring would argue that there is too much reliance on the long term average returns thus allowing pension actuaries to fund their pensions with less money due to assuming higher rates of return.
Instead, one of the areas that may help the crippling pension system in the US is to get realistic about long term returns and use a combination of a smaller returns, and bigger contributions (among others).
The book is heavy on the analytic side (great for our quant readers) but offers substantial insight in plain English on what led to the current pension crisis while offering a mathematically possible solution that relies on real numbers and not hypothetical long term average returns.