In the 2004 wave 1 SIPP questionnaire, new and expanded follow-up questions were implemented in response to an initial "don't know (D) or refusal (R) nonresponsive to questions concerning the amount of income produced by a person's assets. These follow-ups provide initial nonrespondents with a multiple-choice range of income amounts from which to select, with varying cut-points depending on the specific asset type and the time period over which the income is to be reported.