Us federal income tax is progressive by law, but which best explains why is it sometimes regressive in practice?

Label each of the following statements true, false, or uncertain. explain your choice carefully. a. workers benefit equally from the process of creative destruction. b. in the past two decades, the real wages of low-skill u.s. workers have declined relative to the real wages of high-skill workers. c. technological progress leads to a decrease in employment if, and only if, the increase in output is smaller than the increase in productivity. d. the apparent decrease in the natural rate of unemployment in the united states in the second-half of the 1990s can be explained by the fact that productivity growth was unexpectedly high during that period.