A 2013 study was undertaken by a team of researchers with doctorates in nutrition and medicine at an accredited research university. The study investigated risk factors for vitamin d deficiency in people who live in denmark and people who live in australia. By studying patterns in the population, the researchers demonstrated a correlation between the lack of sunny days in denmark and the high incidence of osteoporosis there, compared to the abundant sunny days and low incidence of osteoporosis in australia. However, the results could not rule out other factors in the subject's diet or lifestyle as possible causes of the discrepancy in incidence.

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.