Small reductions in blood pressure (BP) on a population level could have a substantial impact on cardiovascular disease risk.1 This is especially relevant considering that the majority of the population has suboptimal BP levels. Dietary sodium reduction is a clearly established lifestyle change that has great potential to improve public health. Potassium, on the contrary, received much less attention. Nevertheless, a substantial body of data shows that increasing potassium intake lowers BP.2 We reviewed population data on potassium intake and estimated the potential impact of increased potassium intake on population BP levels. Methods.We searched PubMed and contacted health authorities worldwide for national population-based dietary surveys conducted from 1990 to 2009 that included data on potassium intake in more than 1000 adults. We defined the recommended level of potassium intake at 4.7 g/d, based on the Dietary Reference Intakes from the Institute of Medicine.2 The effect of dietary potassium on systolic BP was set at 1.0-mm Hg reduction per 0.6 g/d increase in intake, based on estimates from the INTERSALT study, 3 and we assumed this relation to be linear. Population BP data were obtained for Finland, the United Kingdom, and the United States, representing populations with relatively high, medium, and low po-

Objective. To efficiently estimate race/ethnicity using administrative records to facilitate health care organizations' efforts to address disparities when self-reported race/ ethnicity data are unavailable. Data Source. Surname, geocoded residential address, and self-reported race/ethnicity from 1,973,362 enrollees of a national health plan. Study Design. We compare the accuracy of a Bayesian approach to combining surname and geocoded information to estimate race/ethnicity to two other indirect methods: a non-Bayesian method that combines surname and geocoded information and geocoded information alone. We assess accuracy with respect to estimating (1) individual race/ethnicity and (2) overall racial/ethnic prevalence in a population. Principal Findings. The Bayesian approach was 74 percent more efficient than geocoding alone in estimating individual race/ethnicity and 56 percent more efficient in estimating the prevalence of racial/ethnic groups, outperforming the non-Bayesian hybrid on both measures. The non-Bayesian hybrid was more efficient than geocoding alone in estimating individual race/ethnicity but less efficient with respect to prevalence ( po.05 for all differences). Conclusions. The Bayesian Surname and Geocoding (BSG) method presented here efficiently integrates administrative data, substantially improving upon what is possible with a single source or from other hybrid methods; it offers a powerful tool that can help health care organizations address disparities until self-reported race/ethnicity data are available.

We examine repeat migration sequences in the United States especially those that entail a return, using data from the Panel Study of Income Dynamics. Our guiding hypotheses derive from the concepts of location-specific capital and imperfect information. Descriptive analysis elucidates the dynamics, tempo, and differential frequency of repeat migration among various socioeconomic groups. Results disclose difference among migrants who choose to return or move onward to a new location, or do not move again, and lend support to our analytical framework. Major findings are: (1) the propensity to return to an area varies directly with the amount of location-specific capital that is left behind and inversely with the ex-resident's length of absence, (2) which repeat migration sequence unfolds--return or onward--depends on the ex-resident's educational level and experience of unemployment.

This research has two purposes. First, it examines individual- and household-level factors related to the propensity to move. The findings reveal that mobility is largely a matter of habitual movers changing residence repeatedly and frequently. The second objective is concerned with strengthening the foundation for projecting aggregate levels of mobility: (1) how does repeated movement manifest itself at the metropolitan scale? and (2) for predictive purposes, which aggregate indices capture the most important features of local population composition? Mobility rates were found to vary principally with the prevalence of chronic movers in an SMSA. These findings have several implications for policies designed to guide future population distribution. First, an SMSA’s capacity to correct local manpower imbalances by exchanging human capital with other areas may depend partially on its relative abundance of habitual movers. Second, the likelihood that new cities would attract disproportionate numbers of hypermobile persons might enhance their role within the framework of a broader distribution policy. The question posed here is whether high intrinsic levels of population turnover in some cities might fit into a larger strategy for realigning population growth and distribution nationally.