Department of Economics
Vari Hall 1068, 4700 Keele St
Toronto, ON, M3J 1P3, Canada
NBER Working Papers and Publications
|July 2009||Seam Bias, Multiple-State, Multiple-Spell Duration Models and the Employment Dynamics of Disadvantaged Women|
with John C. Ham, Lara Shore-Sheppard: w15151
Panel surveys generally suffer from "seam bias"--too few transitions observed within reference periods and too many reported between interviews. Seam bias is likely to affect duration models severely since both the start date and the end date of a spell may be misreported. In this paper we examine the employment dynamics of disadvantaged single mothers in the Survey of Income and Program Participation (SIPP) while correcting for seam bias in reported employment status. We develop parametric misreporting models for use in multi-state, multi-spell duration analysis; the models are identified if misreporting parameters are the same for fresh and left-censored spells of the same type. We extend these models to allow misreporting to depend on individual characteristics and for a certain fract...