Base table
\beɪs\ \ˈteɪbəl\
A set of age-specific rates of assumed mortality (or survival), intended to represent a snapshot of mortality at a specific point of time in a given population without any allowance for future variation.
For pension plan valuations, off-the-shelf mortality tables may be crudely tailored by reference to actual experience in large pension plans, but this requires large volumes of data to see through the statistical ‘noise’. The rates in an off-the-shelf standard table may be adjusted by applying an age rating and/or a scaling factor.