Which of the following is a main economic variable that affects business cycles?
a. stagflation

b. national income accounting

c. interest rates

d. personal savings

"Personal savings" is the one among the following choices given in the question that is a main economic variable that affects business cycles. The correct option among all the options that are given in the question is the fourth option or option "D". I hope that this is the answer that has come to your help.

The changes to agriculture in the united states since 1900 is that increased mechanization has increased food production, thereby increasing the need for labor. there has been an increased need for higher speeds of food production due the fact that the population in the united states continues to rise.