Title: Investment Course III
1Investment Course III November 2007
- Topic Seven
- Portfolio Optimization Case Studies
2Portfolio Optimization Example 1 2003 Texas
Teachers Retirement System
- Background Texas Teachers Retirement System
(TRS) is a public defined-benefit pension fund
dedicated to delivering retirement benefits and
related services for more than 1,000,000 public
education employees and their annuitants in the
state of Texas. It currently has more than USD
90 billion of assets under management. - Investment Problem The Board of Trustees at TRS
faces a typical asset-liability management
problem in that they must invest so as to
simultaneously satisfy the income needs of
current retirees and beneficiaries as well as
provide sufficient asset growth to provide for
future funding needs. The system is currently
underfunded relative to actuarial liabilities,
largely due to the fact that contributions from
the state legislature have not kept pace with
needs. - Portfolio Optimization Application Mean-variance
optimization approach across multiple asset
classes, including U.S. equity, non-U.S. equity,
fixed-income, private equity, strategically
traded (i.e., hedge funds), and real estate. - Miscellaneous Issues
- - Ennis Knupp Associates in the main economic
consultant to the TRS Board - - TRS is required by state law to revisit
strategic allocation process every 3-5 years
3TRS Initial Strategic Allocation Comparable
Portfolios
4Texas Teachers Retirement System Optimization
Process Overview
5TRS Steps in the Process
- Establish assumptions and simulate key economic
variables - Inflation (price and wage)
- Interest rates
- Asset class returns, volatility and correlations
- Use simulations to develop plan financial results
over forecast period - Summarize and graph results
- Trends
- Range and distribution of results (i.e.
uncertainty or risk) - Test impact of alternative equity allocation
targets
6TRS Unfunded Status
- A contribution from the State of Texas of about
(12 x Pay) would be required to fund the normal
cost plus amortize a 22 billion unfunded
actuarial liability over 30 years
7TRS Economic Assumptions for the Forecast
- Each forecast reflects a specific scenario for
future rates of inflation, wage increases, bond
yields and asset class returns - These variables will be different than the
actuarial assumptions, thus producing actuarial
gains or losses that are recognized in the
forecast results just as happens in each years
actuarial valuation results - For the baseline forecast, best estimate
assumptions are used - For simulation runs, the model produces 500
different scenarios with year-to-year
fluctuations in each economic variable but the
average result across all 500 scenarios will
closely match the best estimate assumptions from
the baseline forecast
8TRS Example of Simulation-Based Forecasting
Process
10-yr. Bond Yield
Wage Inflation
Price Inflation
Compound average price inflation over 15
years is 3.00. Compound average wage
inflation over 15 years is 4.00. A
merit/promotional increase is added to wage
inflation to get the total salary increase
rate.
9TRS Asset Class Mix and Assumptions
10TRS Gross Return Simulations with Different
Equity Levels in Portfolio
8.52
4.65
7.36
100 Equity
0 Equity
70 Equity
30 Fixed
0 Fixed
100 Fixed
100 Equity
70 Equity
0 Equity
11TRS Forecast Results With Full Simulation
- Six different sets of results, based on two key
variables - Three different rates of employer contribution
(as of pay) - 6 (current)
- 10 (constitutional max)
- 14 (approximate rate for 30-year amortization of
UAL, plus a 2 cushion) - Two different assumptions for ad hoc benefit
increases to retirees - No ad hoc increases
- Increases to match CPI each year
- Funded ratio results actuarial value of assets
/ actuarial value of liabilities - Based on current actuarial assumptions in almost
all scenarios - Only in some of the scenarios where market
interest rates move to (and stay at) extreme
levels do we assume that changes in the actuarial
assumptions would be made
12Question How Much Equity to Include in the TRS
Portfolio?
- First analysis is for the result set that puts
the lowest emphasis on the need for high equity
returns to maintain funded status - Assume contributions are at 14 of pay
- Assume no ad hoc increases for retirees
- Look at distribution of final (year 15) funded
position and the contribution required to fund it - Final unfunded liability final actuarial
liability minus final market value of assets - Calculate the additional contribution ( pay)
that would be required over the 15 year forecast
period to fully fund the final unfunded liability
call this the full funding cost add-on - Put no weight on any final surplus assets (i.e.
the required contribution above is never less
than zero) - Repeat for various equity allocation targets
- Perform risk / reward analysis
- Reward average of all 500 simulated scenarios
- Risk average of the worst 100 simulated
scenarios - Plot the changes in risk and reward measures vs.
current policy - Repeat analysis using a result set that puts more
emphasis on the need for high equity returns to
maintain funded status (10 contributions full
ad hocs)
13Example of Simulation Analysis on Final Funded
Ratio 14 Contributions No Ad Hocs
14TRS Notion of Risk-Reward Analysis
Benchmark ( current mix)
Lower cost
Less risk
Avg. Cost Savings ( Pay) (All 500 scenarios)
More risk
Higher cost
Avg. Risk Increase ( Pay) (Worst 100 scenarios)
Change in cost relative to benchmark values
2.19
15TRS Risk-Reward Analysis for Different Equity
Levels
Benchmark ( current 70)
60
Avg. Cost Savings ( Pay) (All 500 scenarios)
50
80
90
40
Avg. Risk Increase ( Pay) (Worst 100 scenarios)
Conclusion Based on this analysis, a reduction
in the equity allocation to as low as 40 could
be justified. At 60 equity, risk is reduced,
but the average cost remains essentially
unchanged.
2.20
16TRS Mean-Variance Optimization Inputs and Results
17Texas Teachers Retirement System (cont.)
18Texas Teachers Retirement System (cont.)
19Texas Teachers Retirement System 2007 Update
20Texas Teachers Retirement System 2007 Update
(cont.)
21Portfolio Optimization Example 2 2004 Chilean
Pension System (Source Fidelity Investments)
- Background System of private pension accounts
since 1980. Beneficiaries select among several
different investment managers (i.e., AFPs), which
in turn over five different asset allocation
alternatives. Constraints exist as to how much
non-CLP investment can occur and what form the
foreign investments must take. - Investment Problem What are the optimal
strategic asset allocations for the Chilean
pension funds? - Portfolio Optimization Application Augmented
mean-variance optimization using three Chilean
asset classes (stocks, bonds, cash) and four
foreign asset classes (U.S. stocks, U.S. bonds,
Developed Non-U.S. stocks, Developed Non-U.S.
bonds) - Miscellaneous Issue Optimization process uses
the Resampled Frontier approach to reduce
estimation error problems
22Two Approaches to the Chilean Pension Investment
Problem
- Defined Benefit (DB)
- - Immunize the future liability stream (or
manage the surplus) - - All individuals treated identically within
the overall plan - Defined Contribution (DC)
- - Maximize wealth at retirement subject to risk
- - Provide efficient portfolios in absolute
return/risk space - - Individuals select risk/return profile based
on preferences - Analysis requires
- - Long-term expected asset class returns
- - Asset class covariances
- - Appropriate portfolio construction
23Chile Base Case Assumptions
- Base Case Assumptions
- Expected real returns based on 1954 2003 risk
premiums - Real returns for developed market stocks and
bonds areGDP-weighted excluding US
(equally-weighted returns for stocks and bonds
are 5.73 and 1.39, respectively) - Chilean risk-premium volatility estimates
exclude the period 1/72 12/75
24Chile Base Case Assumptions (cont.)
- Correlation matrix is based on real returns
from the period 1/93 6/03 using Chilean
inflation and based in Chilean pesos - Real
returns for developed market stocks and bonds
areGDP-weighted excluding US
25Chile Notion of a Resampled Efficient Frontier
- Problems with traditional mean-variance
optimization - Rare events such as unusually low or high returns
greatly affect the result of the optimization
(maximizing sampling error) - Length of data series is crucial -- the longer
the forecasting period, the longer data series
are required - Optimal efficient frontier may not be optimal
and should not be used to make all asset
allocation decisions
26Chile Notion of a Resampled Efficient Frontier
(cont.)
- Created by Richard Michaud, resampling is a Monte
Carlo technique for estimating the inputs of a
mean-variance efficient frontier that results in
well-diversified portfolios. - Concept of a Resampled Efficient Frontier
- Take a random sample of observation from a
universe of asset class returns (e.g., 30 of 60
months) and calculate the efficient frontier - Divide this efficient frontier into 20 regions by
risk or expected return and look at the median
allocation in each of these regions - Repeat these steps for a new sampling of the
asset class return universe - Generate a large collection of efficient
frontiers by repeated sampling of the return
universe (e.g., 500-1000 trials) - Average all of the regional allocations across
the collection of optimization trials this is
the resampled efficient frontier
27Chile Notion of a Resampled Efficient Frontier
(cont.)
- Resampling provides a more realistic and reliable
risk/return structure - Robust estimate of underlying distributions
- While the weights on the actual frontier change
erratically, the resampled weights are evenly
distributed along the points on the efficient
frontier - With the actual efficient frontier, a marginal
change in risk or return can bring about a
dramatic change in the optimal allocation. With
the resampled frontier, the changes in weights
are always smooth - Potential shortcomings of resampling
- Lack of theory (i.e., no reason why resampled
portfolios will be optimal) - No framework for incorporating tactical views
28Chile Traditional vs. Resampled Efficient
Frontier
29Chile Base Case Unconstrained Resampled Frontier
30Chile Base Case Unconstrained Resampled Frontier
(cont.)
31Chile Base Case Unconstrained Resampled Frontier
(cont.)
Unconstrained Frontier
32Chile Modifying the Unconstrained Optimization
Constraint Set
33Chile Modifying the Unconstrained Optimization
(cont.)
Constrained Frontier for Fund A
34Chile Comparing Optimal Allocations Across
Constraints
Asset Allocations of Various Funds Using Point 20
on Unconstrained Frontier
35Chile Comparing Optimal Allocations Across
Constraints (cont.)
Asset Allocations of Various Funds Using Point 15
on Unconstrained Frontier
36Portfolio Optimization Example 3 2005
University of Texas Investment Management Company
- Background The University of Texas Investment
Management Company (UTIMCO) is a private company
whose only client is the public endowment fund
holding the assets of the University of Texas and
Texas AM University Systems. It currently has
about USD 16 billion under management. - Investment Problem The Board of Directors of
UTIMCO faces a multi-dimensional investment
problem that involves both short- and
intermediate-term funding needs for the various
campuses in the UT and AM systems as well as
long-term growth goals. Although UT is a public
university, the UTIMCO staff feels that it must
produce investment returns that are comparable to
the endowments of Harvard and Yale Universities. - Portfolio Optimization Application Mean-downside
risk optimization approach across multiple asset
classes, including U.S. equity, non-U.S. equity,
fixed-income, private equity, hedge funds, and
real estate. - Miscellaneous Issues
- The downside risk threshold is the funding rate
that is projected by the Systems Board of
Regents, which consists of politically appointed
members. - Cambridge Associates is the primary economic
consultant to the UTIMCO Board
37UTIMCO Initial Asset Allocation and Issues to
Address
- Benchmark for Developed International and
Emerging Markets - Target and Upper Limit Identical in Hedge Funds
- Target and Upper Limit Identical in Private
Equity - Target and Lower Limit Identical in Fixed Income
- Remove REITS From US Equity Category
- Remove TIPS From Fixed Income Category
- Reinstate Inflation Hedge Category
- Liquidity Policy is Inconsistent With Asset
Allocation Policy
May, 2005
36
38UTIMCO How Competitive is the Current Allocation
Policy?
May, 2005
37
39UTIMCO Recent Performance Relative to Large
Endowment Peers
May, 2005
38
40UTIMCO Inputs for the Asset Obligation
Optimization Process
- The Asset Obligation Optimization Process
Requires the Following Assumptions - Expected Returns
- Expected Risk and Risk Profile
- Correlations Between Expected Returns Across
Asset Categories - The Minimum Acceptable Return (or MAR)
March, 2005
16
41UTIMCO Developing Return Assumptions Through the
Risk Premium Approach
March, 2005
18
42UTIMCO Developing Return Assumptions by Building
Economic Return Components
March, 2005
19
43UTIMCO Notion of Potential Value Added (PVA)
- Potential Value-Added (PVA) is the opportunity to
increase returns beyond those generally available
in an asset class through active management, - PVA takes two forms
- PVA by an active manager is the result of
effective security selection usually based on
extensive research and analysis skills, - PVA by staff can result from a wide range of
sources including skill in manager selection,
term negotiations, manager monitoring, responses
to periodic special opportunities in the markets,
and risk control. - The objective at UTIMCO is to focus on high PVA
opportunities, developing or purchasing the
skills necessary to earn attractive returns.
March, 2005
23
44UTIMCO Measuring PVA Across Asset Classes
- High value-added spread equals high PVA,
- PVA spreads measure the opportunity for
value-added - Realistic assumptions on future value-added
spreads are the basis for PVA projections - A realistic evaluation of staff and external
manager skills leads to an estimated Capture
Ratio that defines the portion of the total
value-added spreads we expect to earn in excess
returns
March, 2005
24
45UTIMCO Efficient Frontier With PVA
46UTIMCO Recommended 2005 Return and Risk
Assumptions With PVA
May, 2005
45
47UTIMCO Recommended 2005 Return and Risk
Assumptions With PVA (cont.)
May, 2005
46
48UTIMCO Risk Framework
49UTIMCO Developing Return Correlations Assumptions
May, 2005
48
50UTIMCO Developing Return Correlations
Assumptions (cont.)
May, 2005
49
51UTIMCO Recommended Return Correlations
Assumptions
May, 2005
50
52UTIMCO Developing the Downside Risk Threshold
May, 2005
51
53UTIMCO Some Thoughts About Investment
Restrictions
- Constraints Should be Considered Carefully
- They Might be Useful to Express Uncertainty
Rather Than Aversion - Constraints Should Define Unacceptable, Not Just
Undesirable, Alternatives - Remember That Every Constraint Has a Real Cost
(We will show the estimated costs of all
constraints adopted.)
May, 2005
52
54UTIMCO The Cost of Constraint - 2003 Allocation
March, 2005
39
55UTIMCO Existing and Recommended Constraints
May, 2005
54
56UTIMCO Existing and Recommended Constraints
(cont.)
May, 2005
55
57UTIMCO Mean-Downside Risk Optimization
Candidate Policy Portfolios Derived From 2005
Capital Market Assumptions
May, 2005
56
58UTIMCO 2005 Candidate Policy Portfolios No
Constraints
May, 2005
57
59UTIMCO 2005 Candidate Policy Portfolios 30
Hedge Fund Constraint
May, 2005
58
60UTIMCO Selecting a Strategic Asset Allocation
- The portfolio optimization processregardless how
the investment problem is framedresults in an
optimal set of asset allocations that are
efficient in the sense each optimal allocation
minimizes risk for a given return goal - Once the efficient frontier is established,
investors must next answer the following
question Which single allocation (or range of
allocations) from the efficient frontier is
appropriate for them? - Decisions Factors represent one approach to this
problem. A decision factor is a measure or
characteristic which may be used to relate
specific goals to a particular decision.
61UTIMCO How Decision Factors Work
Idea A portfolio optimization simulation can be
designed to determine which potential asset
allocation would be optimal for each decision
factor (or combination of factors).
May, 2005
60
62UTIMCO Specific Decision Factors Voting Process
12.2
12.2
18.3
6.1
24.4
18.3
6.1
2.4
May, 2005
61
63UTIMCO Decision Factor Scores for Candidate
Policy Portfolios
May, 2005
62
64UTIMCO 2005 Policy Asset Allocation Comparison
May, 2005
63
65UTIMCO 2007 Update Asset Classification
66UTIMCO 2007 Update Asset Allocation