n is middle age and skin thickness is low. In these conditions, the marginal change in the probability of diabetes is about 3%, but the AME of age is nearly zero at higher and lower ages. Indeed, as skin thickness increases, the marginal effect of age flattens out and actually becomes negative (such that increasing age actually decreases the probability of diabetes for women with thick arms).</p>
<p>Now let’s examine the average marginal effects of skin thickness across levels of age and skin thickness:</