If markets are efficient, what should be the correlation coefficient between stock returns for two nonoverlapping time periods?

As a result of a labeling mistake at the chemical factory, a farmer accidentally sprays weedkiller rather than fertilizer on half her land. as a result, she loses half of her productive farmland. if the property of diminishing returns applies to all factors of production, she should expect to seea. a decrease in the marginal productivity of her remaining land and an increase in the marginal productivity of her labor. b. an increase in the marginal productivity of her remaining land and an increase in the marginal productivity of her labor. c. an increase in the marginal productivity of her remaining land and a decrease in the marginal productivity of her labor. d. a decrease in the marginal productivity of her remaining land and a decrease in the marginal productivity of her labor.