The multiple-race population of the United States: issues and estimates.

This paper presents national estimates of the population likely to identify with more than one race in the 2000 census as a result of a new federal policy allowing multiple racial identification. A large number of race-based public policies-including affirmative action and the redistricting provisions of the Voting Rights Act-may be affected by the shift of some 8-18 million people out of traditional single-race statistical groups. The declines in single-race populations resulting from the new classification procedure are likely to be greater in magnitude than the net undercount in the U.S. census at the center of the controversy over using census sampling. Based on ancestry data in the 1990 census and experimental survey results from the 1995 Current Population Survey, we estimate that 3. 1-6.6% of the U.S. population is likely to mark multiple races. Our results are substantially higher than those suggested by previous research and have implications for the coding, reporting, and use of multiple response racial data by government and researchers. The change in racial classification may pose new conundrums for the implementation of race-based public policies, which have faced increasing criticism in recent years.

Kinship networks that cross racial lines: the exception or the rule?

I estimate the frequencies of interracial kin relations, an important indicator of the isolation of racial groups in the United States. I use two techniques to estimate the size and heterogeneity of extended families. First, I develop a simple model that takes account only of kinship network sizes and intermarriage levels by race. This model allows a crude estimation of the frequency of multiracial kinship networks. Second, I produce more precise empirical estimates using a new hot-deck imputation method for synthesizing kinship networks from household-level survey data (the June 1990 Current Population Survey and the 1994 General Social Survey). One in seven whites, one in three blacks, four in five Asians, and more than 19 in 20 American Indians are closely related to someone of a different racial group. Despite an intermarriage rate of about 1%, about 20% of Americans count someone from a different racial group among their kin.

The leveling of divorce in the United States.

Is the recent plateau in crude divorce rates due to compositional changes in the married population or to a fundamental change in the long-term trend of rising marital instability? I use refined measures of period divorce rates to show that the leveling of divorce rates appears to be real. Compositional factors do little to explain the end to the more than century-long pattern of rising divorce. Increases in cohabitation also fail to explain the plateau. New theories are needed to explain the determinants of divorce rates at the population level.

Intrarenal hemodynamics in acute myohemoglobinuric renal failure.

Renal blood flow (RBF) and its distribution were measured in acute renal failure induced by glycerol injection to water-drinking rats and to rats chronically loaded with NaCl solution. Mean RBF and intracortical blood flow distribution of both water-drinking and saline-loaded rats at 24 h after glycerol injection were not different from those of control rats. Although chronic saline loading blunted the impairment of renal function caused by glycerol as evidenced by serum creatinine values, no differences in renal hemodynamics were noted. This suggests that changes in glomerular arteriolar resistance or glomerular permeability might be of greater importance in the reduction of glomerular filtration rate than are alterations of blood flow.