=+model proposed by the authors was where the variables are defined as follows y 5 ecology score (higher values indicate a greater concern for ecology)

x1 5 age times 10 x2 5 income (in thousands of dollars)

x3 5 gender (1 5 male, 0 5 female)

x4 5 race (1 5 white, 0 5 nonwhite)

x5 5 education (in years)