May 8, 2006, Reviewed January 7, 2008
On-line lenders who show different rate/point combinations invariably
show APRs below the interest rate on low-rate loans carrying discounts,
whereas on high-rate loans carrying premiums, the APR equals the rate.
Borrowers should ignore this pattern, it is an artificial construct
stemming from the way in which APR is defined.
"In shopping on-line, I have run into something puzzling. All the
mortgage shopping sites you recommend show different combinations of
interest rate and points, and in every case, the Annual Percentage Rate
(APR) is lower on loans with lower rates. The APR makes low rate/high
point mortgages look like bargains. Are they?"
No, there are no bargains in this market. The APR is consistently lower
on low-rate loans than on high-rate loans because it isn’t calculated
properly. That isn’t the lenders’ fault, they must calculate the APR
using Government rules. But the rules don’t correspond to lender
practice in pricing loans, or to borrower needs.
How Lenders Price Mortgages With Different Interest Rates
Lenders price loans with different rates so that their net return on
investment will be about the same. Suppose they offer a 6.375% loan at a
price of zero, meaning there are no upfront loan charges. This is called
the "par mortgage."* Then on a 5.875% loan they are going to require an
upfront payment that, combined with the 5.875% rate, will yield 6.375%.
Similarly, on a 7% loan, they will offer a rebate that, combined with
the 7% rate, will yield 6.375%.
In pricing loans having different rates, lenders must make assumptions
about when the loan will be repaid. The shorter the life of a loan with
a rate below or above the par rate, the smaller the upfront payment or
rebate required to generate the same yield as the par mortgage.
For example, to yield 6.375%, a 5.875% 30-year loan requires an upfront
payment of 5.2% of the loan if the loan runs to term. But if the loan is
paid off in 6 years, the required upfront payment is only 2.4%.
Similarly, to yield 6.375% a 7% 30-year mortgage requires a rebate of
6.9% if the loan runs to term, but only 3.1% if it is paid off in 6
years.
Calculating Mortgage Life Implied by Lender Pricing
From lender rate/price quotes, it is possible to derive the implied
assumptions about loan longevity. I did this for a 30-year fixed-rate
mortgage on April 28, 2006 using data on Amerisave.com. The par mortgage
had a rate of 6.375%, and I assumed that other rates were priced to
yield 6.375%.
The 5.875% mortgage carried an upfront payment of 2.3%, which (to yield
6.375%) implied a life of 70 months. The 5.25% mortgage carried an
upfront payment of 5.6%, which implied a life of 76 months. The 6.875%
mortgage carried an upfront rebate of 1.8%, which implied a life of 49
months. The 7.5% mortgage carried an upfront payment of 3.3%, which
implied a life of 39 months. (Note: The assumed length of life declines
as the rate goes up because higher-rate mortgages are more likely to be
refinanced).
Why the APR is Biased in Favor of Low-Rate/High-Fee Mortgages
The APR is a composite measure of the cost of credit to the borrower
that takes account of all upfront lender charges or rebates, in addition
to the rate. On the par mortgage, the APR is equal to the rate. If it
used the same assumption about mortgage life as lenders, the APR for
mortgages having different rates would be close to the par rate. But
that is not the rule.
The rule is that the APR is calculated on the assumption that all
mortgages run to term. This makes the APR lower than the par rate on all
mortgages with rates below the par rate. On mortgages with rates above
the par rate, the APR equals the rate because the rebates paid by
lenders on above-par loans, which are used by borrowers to pay third
party settlement costs, do not reduce the APR because the APR does not
include these costs. (See
Annual Percentage
Rate Below Interest Rate on FRMs). This pattern is wholly artificial
and should be disregarded by borrowers. It is unfortunate that on-line
lenders have to waste scarce screen space on it.
For the last 20 years I have been asking the Federal Reserve to drop the
assumption used in calculating the APR, that all loans run to term. More
than 90% of them don’t. The APR would become a useful measure if it was
calculated using length-of-life assumptions that vary with the rate, as
lenders do. It would be even more useful if it were calculated over the
period each individual borrower expects to have the mortgage. With
today’s technology, that is not difficult.
Meanwhile, if you have the money to pay points (referred to as "buying
down the interest rate"), it is a good investment if you expect to have
the mortgage at least four years. If you are cash-short, the rebate paid
by a lender on high-rate loans can be used to defray settlement costs.
However, it becomes extremely expensive if you don’t pay off the loan
within 3 years.
*Sometimes the par mortgage is defined as the mortgage with zero points,
rather than the mortgage with zero total loan fees. If a loan has zero
points but some fixed-dollar loan fees, the APR will be higher than the
rate.