20 FEDERAL SUBSIDIES AND THE HOUSING GSEs May 2001
CBO's decision to use the capitalized subsidy
measure is also consistent with the objective of the
Credit Reform Act of 1990, which is to recognize and
disclose the costs of long-lived credit transactions
when the commitment to that assistance is made.
Through law and generally accepted accounting prin-
ciples, the federal government requires that the pres-
ent value of all future benefits conveyed by new
loans and guarantees issued in the current year be
recognized.
12
The subsidy estimates here differ in
some respects from the treatment of financial guaran-
tees under the Credit Reform Act to reflect that there
is no explicit guarantee to the GSEs. Instead, the cal-
culations closely follow private-sector capital budget-
ing practices, which were similarly designed to re-
flect the present value of future commitments.
The more forward-looking approach to measur-
ing subsidies adopted in this study has been recom-
mended by several observers.
13
That method can be
illustrated by a familiar example. If a home buyer
obtains a 30-year fixed-rate $100,000 mortgage at
7.75 percent, rather than 8 percent, the first year’s
savings is $250 (0.25 percentage points times
$100,000). But the borrower will also enjoy interest
savings each year thereafter until the mortgage is
paid off. The sum of lower interest payments in all
years is sometimes (incorrectly) used as the savings
from the lower mortgage rate, but that figure over-
states the benefit to a borrower because it treats a
future dollar saved as equal in value to a dollar saved
today.
14
To adjust for differences in the value of
money over time, future interest savings must be dis-
counted with an appropriate interest rate. Capitaliza-
tion refers to the process of discounting and summing
annual benefits.
Although the basic procedure is straightforward,
its use raises the question of the life of the subsidy
benefit. The GSEs finance mortgages with initial
maturities that are usually 15 or 30 years but that may
be shorter, with debt ranging in maturity from a few
days to 30 years. Maturing or prepaid mortgages are
almost always replaced with new mortgages, extend-
ing the effective life of the subsidy.
CBO has considered two maturity horizons—
seven years and perpetuity—that provide lower and
upper bounds, respectively, for the subsidy estimates.
However, to link the subsidy more explicitly to the
mortgages acquired or guaranteed in a given year, all
subsidy estimates reported in this study use the lower
bound estimate unless otherwise indicated.
15
That
maturity is considerably shorter than the 15- or 30-
year term of a typical new mortgage because a large
fraction of mortgages are paid off early through refi-
nancing or the sale of houses. Because the GSEs
structure their debt financing to match expected mort-
gage cash flows, it is reasonable to expect that the
borrowing advantage on debt is also locked in on av-
erage over that seven-year period.
16
For the seven-year horizon, incremental borrow-
ing in a given year has two components. One compo-
nent is the increase in the total debt that is outstand-
ing. The second component is an estimate of new
mortgages that are replacing mortgages maturing in
the current year, called the “rollover amount” (which
is absent when the maturity horizon is considered to
be perpetuity). The subsidy estimate therefore re-
flects the average life of new mortgages acquired in a
given year, incorporating the sum of new growth and
the rollover of maturing mortgages. To calculate the
rollover amount, CBO assumes a distribution of life-
times for new mortgages and uses this distribution to
12. Credit Reform Act of 1990 and Statement of Federal Financial Ac-
counting Standards 2.
13. Robert S. Seiler Jr., “Estimating the Value and Allocation of Fed-
eral Subsidies to Fannie Mae and Freddie Mac” (paper presented at
the American Enterprise Institute conference “Fannie Mae and
Freddie Mac: Public Purposes and Private Interests,” Washington,
D.C., March 24, 1999), revised April 1, 1999, and Alden L. Toevs,
“A Critique of the CBO’s Sponsorship Benefit Analysis” (report
submitted by First Manhattan Consulting Group to Fannie Mae,
September 6, 2000).
14. A dollar in 30 years is equivalent to only $0.23 today because $0.23
invested at 5 percent today would grow to $1 in 30 years.
15. Over time, the anticipated average life of a mortgage varies because
of variations in the interest rate environment that affect prepayment
rates. In recent years, the average life of a typical mortgage has
been less than seven years. Using seven years as the basis for the
subsidy calculations is conservative, however, because the high
probability that maturing mortgages will be replaced by new mort-
gages implies a much longer effective life of new commitments.
16. Conceptually, the focus is on the life of the mortgages financed,
rather than on the life of the supporting debt, because mortgage
borrowers are the intended beneficiaries of the estimated subsidy
and that subsidy is received over the life of the mortgages. The
average maturity of liabilities rather than of assets could be used to
determine the subsidy horizon and would lead to similar results.
Fannie Mae and Freddie Mac maintain that their interest rate risk is
limited by their hedging strategies. Accordingly, the effective ma-
turity of their liabilities is close to that of their assets.