The ratio of persons uninsured at a point in time to persons uninsured for a full year provides a measure of turnover in the uninsured and therefore a proxy for the duration of uninsurance. Higher ratios imply shorter spells of uninsurance. Table IV.36 presents ratios for the SIPP, MEPS, and NHIS for the entire population, children, and nonelderly adults. Across all populations and poverty brackets, SIPP has the highest ratio, with NHIS narrowly larger than MEPS. For example, among all persons the SIPP ratio is 1.87, followed by 1.50 for NHIS and 1.42 for MEPS. The differences among the surveys narrow among nonelderly adults, with SIPP standing at 1.41, NHIS at 1.25, and MEPS at 1.16. Interestingly, within any age group, the ratios for all three surveys grow with the poverty relative, implying that not only do uninsured rates (for any time period) decline with increasing income; the durations of uninsured spells decline as well.