"[1] This version clarifies that economic assumptions can be based either on the actuary's estimate of future experience or on the actuary's observations of the estimates inherent in market data, depending upon the purpose of the measurement. [2] The guidance regarding the reasonability of an economic assumption has been changed from the 'best-estimate range' standard. [3] This version requires disclosing the rationale used in selecting each nonprescribed economic assumption or any changes made to nonprescribed economic assumptions. [4] The guidance now distinguishes between prescribed assumptions or methods set by law and prescribed assumptions or methods set by another party."