摘要：The influence of socioeconomic variables on nutrient intake is studied using nonparametric procedures that admit estimation of multivariate functions. The analysis indicates a nonlinear relation between intake, age, education, and income. Specifically, intake rises with income reaching an inflection point beyond which it is essentially flat. Socioeconomic variables influence intake primarily at lower income levels. Nonparametric procedures prove useful in avoiding ad hoc specifications that would fail to uncover these findings.
