6. Which of the following is likely to be directly measured in the US GDP estimates, under the expenditure approach, once coronavirus pandemic is over? a) number of bitcoins bought in 2021 b) clean air quality from reduced pollution in 2021 c) an increase in restaurant dining in 2021 d) increased use of informal babysitter services once parents resume work outside home in 2021 7. A country's GDP is expected to grow at a constant rate of 5%, and population grows at rate of 3%. Productivity grows at rate of 2%, and capital share is 1/3. Approximately how many years would it take for a country's total capital stock to double? Assume population is equal to labor force, and the production function is Y = AKall-a a) 14 b) 23 35 d) 10