4.5 According to Card (2009),

(a) workers with less than a high school education are perfect substitutes for those with a high school education,

(b) “high school equivalent” and “college equivalent” workers are imperfect substitutes, and

(c) within education groups, immigrants and natives are imperfect substitutes. For each of these comparisons, draw the isoquants for a production function that uses two types of workers. For example, in part (a), production is a function of workers with a high school diploma and workers with less education.