Evaluating LDI
August 01, 2008 |
Stephen Goldman and Scott McDermott
Ten important questions that
plan sponsors
should ask when considering liability
driven investing.
Falling interest rates, lagging
equity markets and greater volatility
in pension plan solvency
ratios have created renewed
awareness of the risks of pension plan
assets and obligations, and the need to keep
pension plans focused on providing for their
beneficiaries. This has led to a more active
debate in today’s investment community
over how a pension plan can best manage its
assets and its solvency ratio.
Liability driven investing (LDI) is not a
specific investment product. Rather, it is a
way of approaching pension plan management
by combining the best elements of
both growth-driven and immunization
investment strategies. In addition to
considering asset diversification, each of
a pension plan’s investments is evaluated
according to its potential for appreciation
and its potential as a liability hedge, with
the portfolio allocated to strike an appropriate
balance between these two seemingly
contradictory goals.
Due to differences in plan liability
profiles, solvencies and fiduciary risk
appetite, there is no one-size-fits-all LDI
solution. Each pension plan must tailor its
own solution to its particular circumstances.
When evaluating LDI solutions, here are
some key considerations for plan sponsors.
1 Surplus risk –
How big
should the hedge be and
how much interest rate
mismatch is appropriate?
There are four key drivers of surplus risk.
One, the investment policy (the degree to
which the plan takes asset allocation or
beta risk with the expectation of growing
plan assets in excess of liabilities). Two, the
overall liability duration (the sensitivity of
plan liabilities to changes in interest rates).
Three, unhedgeable liability risks (including
mortality, employee turnover, projected future
wage inflation and other actuarial assumptions).
And four, current funded status.
Figure 1 (see below) demonstrates that hedging greater
percentages of the interest rate risk of liabilities leads
to a reduction in surplus risk. However, the marginal
surplus risk reduction beyond a 70% to 80% hedge is minimal
for plans that are simultaneously investing in equities
and other risky growth-oriented investments. Trustee risk
tolerance and asset allocation conviction should drive
the decision of how much mismatch should be retained.
2 Benchmark selection –
What is the right
benchmark?
An actuary’s liability cash flow
projections are usually not investable and
are typically only recalculated once per
year. Therefore, they do not serve as a
useful benchmark. In general, pension plan
fiduciaries will want to adopt a benchmark
that can be customized to the plan’s specific
circumstances and that mimics, to the extent
practicable, the interest rate risk of the plan’s
liability cash flows. While there are a wide
variety of benchmarks available, critical
issues to consider include measurability,
liquidity, transparency and investability.
The answer need not necessarily be a
customized benchmark. Proxy benchmarks
such as the DEX Long Universe, which
approximate a plan’s duration risk, are
most useful when the intent is to hedge
only a fraction of the liability exposure.
These types of benchmarks may also
be appropriate for plans with a shorter
duration and/or greater uncertainty in the
projected benefit stream. Proxy benchmarks
have the advantages of being simple,
publicly recognized, quoted daily and easy
to explain. They have the disadvantages
of embodying some duration, convexity
and/or yield curve sensitivity mismatches
to liabilities, which may not be present in a
customized benchmark.
Customized benchmarks, such as a blend of government
bond or interest rate swaps, improve on a proxy benchmark
by attempting to more closely match the plan’s liability
duration, convexity and yield curve exposures. Customized
benchmarks may be appropriate when the objective is to
hedge a larger fraction of liabilities and may be particularly
suitable for a frozen or closed plan, as there is greater
confidence in the projected liability stream. Possible
disadvantages to a customized benchmark include complexity
and the need to build and maintain such indexes.
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