During the Reagan era, 1981-1988, the U.S. current account moved from a tiny surplus to a large deficit. The following table provides U.S. macroeconomic data for that period.

YEAR		1980	1981	1982	1983	1984	1985	1986	1987	1988
PRIVATE SAVINGS		500	586	617	641	743	736	721	731	802
PRIVATE INVESTMENT		468	558	503	547	719	715	718	749	794
GOVERNMENT BUDGET DEFICIT		-35	-30	-109	-140	-109	-125	-147	-112	-98
CURRENT-ACCOUNT BALANCE		2	5	-11	-45	-100	-125	-151	-167	-129

a. Based on these data, to what extent would you attribute the changes in the U.S. current-account balance to a decline in the U.S. private savings-investment balance?

b. To what extent would you attribute the changes in the U.S. current-account balance to an increase in the U.S. government budget deficit?

c. Based on these data, what was the excess of national spending over national income during this period?