Example: Federal Debt

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This example compares power, exponential, and logistic models of an accelerating upward trend in a data set. It then looks at the differing extrapolated values and contrasts them with official predictions.

The U.S. Federal government has a long history of spending more money each year than it receives. The yearly shortfall in money received compared to money spent is called the (annual) Federal budget deficit.

When you spend more money than you receive, you eventually go into debt, i.e., you will have to borrow money in order to pay your bills. This is also true of the Federal government, which, because of the annual deficits, has accumulated an enormous debt.

When you go into debt, the individuals and institutions that lend you money charge interest, computed as a percentage of the amount of money you currently owe on your loan. Interest is a fee paid to the lender on a regular schedule, such as monthly or yearly. The Federal government is no different: It must also pay interest on the huge Federal debt.

The following table, from the U.S. Department of Treasury, shows actual and extrapolated gross Federal debts (including the interest).

End of Fiscal Year Gross Federal Debt

2003 (Estimate)

$6,336,234 million

2002 (Estimate) $6,203,701 million
2001 (Estimate) $6,078,886 million
2000 (Estimate) $5,915,719 million
1999 (Estimate) $5,738,119 million
1998 (Estimate) $5,543,589 million
1997 (Actual) $5,369,707 million
1996 (Actual) $5,181,934 million
1995 (Actual) $4,921,018 million
1994 (Actual) $4,643,705 million
1993 (Actual) $4,351,416 million
1992 (Actual) $4,002,136 million
1991 (Actual) $3,598,498 million
1990 (Actual) $3,206,564 million
1989 (Actual) $2,868,039 million
1988 (Actual) $2,601,307 million
1987 (Actual) $2,346,125 million
1986 (Actual) $2,120,629 million
1985 (Actual) $1,817,521 million
1984 (Actual) $1,564,657 million
1983 (Actual) $1,371,710 million
1982 (Actual) $1,137,345 million
1981 (Actual) $ 994,845 million
1980 (Actual) $ 909,050 million
1979 (Actual) $ 829,470 million
1978 (Actual) $ 776,602 million
1977 (Actual) $ 706,398 million
1976 (Actual) $ 628,970 million
1975 (Actual) $ 541,925 million
1974 (Actual) $ 483,893 million
1973 (Actual) $ 466,291 million
1972 (Actual) $ 435,936 million
1971 (Actual) $ 408,176 million
1970 (Actual) $ 380,921 million
1969 (Actual) $ 365,769 million
1968 (Actual) $ 368,685 million
1967 (Actual) $ 340,445 million
1966 (Actual) $ 328,498 million
1965 (Actual) $ 322,318 million
1964 (Actual) $ 316,059 million
1963 (Actual) $ 310,324 million
1962 (Actual) $ 302,928 million
1961 (Actual) $ 292,648 million
1960 (Actual) $ 290,525 million
1959 (Actual) $ 287,465 million
1958 (Actual) $ 279,666 million
1957 (Actual) $ 272,252 million
1956 (Actual) $ 272,693 million
1955 (Actual) $ 274,366 million
1954 (Actual) $ 270,812 million
1953 (Actual) $ 265,963 million
1952 (Actual) $ 259,097 million
1951 (Actual) $ 255,288 million
1950 (Actual) $ 256,853 million

 
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