performance measurement 3 Flashcards
risk-free rate of return can be defined as
the rate at which money is borrowed or lent when there is no credit risk, so that the money is certain to be repaid.
Assets issued by national governments in their own currency were traditionally assumed to be “risk free”, and so the risk-free rate was often referred to as the “Treasury rate”.
In practice, and depending on the particular context, the risk-free return might therefore be interpreted as the rate of return offered by:
Treasury bills
short-term conventional government bonds
long-term conventional government bonds
index-linked government bonds.
This assessment was based on the thinking that national governments can always print money to ensure that their debts will be paid. Thus the concept of national debt being risk-free was only valid in a closed economy, where all financial transactions are in the currency of that economy. This feature was seen in much of the early part of the twentieth century, where large economies of China and the Soviet Union were effectively closed to outside influence.
However, as recent events have demonstrated, the ability of governments to print money is a route not available to governments that use a shared currency (such as the euro), or those who wish to tie their exchange rate closely to something else (like the dollar).
However in practice at the current time, all economies interact with each other, and therefore currency risk needs to be taken into account. Printing money deflates its value against other currencies, and thus the holder of overseas government debt may not receive a return that is free of currency risk, or is risk free in real terms if the inflation rates in the overseas territory and in the domestic economy of the holder differ.
For this reason the main rating agencies assign a credit rating to the government debt of most countries, generally assessed against the US Dollar. One key measure to be considered is the ratio of outstanding debt to GDP, as well as the maturity of the existing debt, since this will determine the cost of servicing the debt and the need to raise refinancing capital as existing debt matures.
Asset liability modelling
Perhaps the most important practical actuarial technique for use in determining an investment strategy nowadays is asset liability modelling.
Asset models and the fundamentals of Asset Liability Modelling were discussed in the Core Reading for Subject A301.
investor’s objectives will normally be stated with reference to both
assets and liabilities. In setting an investment strategy to control the risk of failing to meet the objectives a method of taking into account the variation in the assets simultaneously with the variation in the liabilities is required. This can be done by constructing a model to project the asset proceeds and liability outgo into the future.
In other words, by constructing and using an asset liability model.
The outcome of a particular investment strategy is examined with the model and compared with the investment objectives. The investment strategy is adjusted in the light of the results obtained and the process repeated until the optimal strategy is reached.
The optimal strategy being that which best meets the objectives of the investor.
Models can either be deterministic or stochastic. In both deterministic and stochastic models it is important that the assumptions made in constructing the model are consistent with each other.
It is essential to ensure that the assumptions and parameter values underlying both the assets and the liabilities are consistent if sensible results are to be obtained. In practice, this may be achieved by modelling of the appropriate dynamic links between assets and liabilities. For example, in many models inflation is assumed to influence both the asset returns and the liabilities.
Advantages of asset liability modelling
encourages investors to formulate explicit objectives. The objectives should include a quantifiable and measurable performance target, defined performance horizons and quantified confidence levels for achieving the target.
a typical objective might be to:
maximise the expected solvency level
at the end of a 3-year period
subject to the probability of insolvency at any time over that period being no more than 0.1%
For an institution such as a pension fund or insurance company the objectives might be specified in terms of the results of a valuation carried out at a specified time in the future. In practice there is likely to be feedback between the model output and the setting of the objectives. This may be because the additional insight provided by the model projections may help the investor to refine its investment objectives.
The success of the strategy is monitored by means of regular valuations. The valuation results will be compared with the projections from the modelling process and adjustments made to the strategy to control the level of risk if necessary. The model itself may also be refined in the light of how the actual experience compares to that which it predicted.
Deterministic asset liability modelling
A deterministic model is based on a single set of assumptions about future experience. Using the assumptions we project the asset proceeds and liability outgo for each future time period. We can then compare the incidence of income and outgo to check that the outgo can always be met. We will also want to know the value of assets and the value of liabilities at each future time period according to one or more valuation bases.
Stochastic asset liability modelling
In contrast to a deterministic model, a stochastic model treats the key parameters as random variables with a given mean and a defined probability distribution. For example, future inflation might be defined by a normal distribution with mean of 5% and standard deviation of 2%, and real interest rates (ie the excess of nominal short- term interest rates over inflation) might be distributed between –2% and +8%, say.
What assumptions would be required in an asset model used to estimate the future income stream and asset values of an investment portfolio?
.
In practice, we might develop a stochastic asset model in which each of the key variables is modelled as a random variable, typically depending upon
past values of itself
present and past values of other economic and/or investment variables.
Having run the model a large number of times, we would scan the results from each simulation to gauge how likely it is for an unsatisfactory result to emerge. For example, we might define an unsatisfactory result as the company becoming insolvent.
If say seven out of 1,000 simulations resulted in insolvency at some point over the projection period, then we might conclude that the probability of insolvency or ruin over that period is about 0.7%. A further set of simulations could then be performed based on a different investment strategy to see how the probability of ruin compared. By repeating the projections for a suitable number of different investment strategies, we can ultimately determine which is optimal in terms of best meeting our investment objectives.
It is important that the particular structure of the model and value of the parameters depend on the purpose of the model. Although there are powerful statistical techniques to aid in the construction of the model, it will be necessary to apply judgement in establishing the most appropriate form and appropriate value of the parameters. If the results are to be used in an intelligent and critical manner, the actuary should be aware of the strengths and weaknesses of a particular model before interpreting the output.
Using a stochastic model is, arguably, the most appropriate way of allowing for the volatility and uncertainty underlying the assets and liabilities. However, this is highly dependent on whether we can specify probability distribution functions that reflect the true level of uncertainty.
Asset liability modelling is discussed further in Chapter 18.
What is the main problem with relying solely on past data to develop a stochastic asset model?
.
What are the two main risks involved in the development of an asset liability model?
.
List five “actuarial” techniques that may be used to develop an appropriate investment strategy and that take into account the liabilities.
.
Financial risks
The financial risks faced by an institutional investor can be considered under five headings, according to the source of the risk:
1. Market risk is the risk relating to changes in the value of the portfolio due to movements in the market value of the assets held. 2. Credit risk is the risk that a counterparty to an agreement will be unable or unwilling to fulfil their obligations. 3. Operational risk is the risk of loss due to fraud or mismanagement within the fund management organisation itself. 4. Liquidity risk is the risk of not having sufficient cash to meet operational needs at all times. It is related to market risk in as much as the liquidity of the overall portfolio is need to be taken into account in portfolio selection. 5. Relative performance risk is the risk of under-performing comparable institutional investors.
Monitoring and controlling market risk Introduction
For many institutional investors, variations in the market values of its assets represent the main risk of failing to meet its investment objectives. For example, a fall in asset values to levels far below those anticipated may threaten the financial integrity of the institution. It is therefore crucial to try and control market risk. The first steps in the control process will be to:
identify and define the risks
develop techniques and/or models by which to quantify such risks.