Reply to
@scott:
Hi Scott,
Thanks for your reference to AQR
Capital Management’s interpretation and implementation of the Risk Parity concept. Although I am generally familiar with the concept, my understanding of its details, especially its execution aspects, is extremely shallow. Your reference has somewhat deepened my knowledge base.
I downloaded the AQR document and spent an hour reviewing it. In the spirit of the Internet, here is my WikiView of the paper.
I am favorably impressed by the directness, the honesty, and the technical characteristics of the report. Its content clearly identifies the prospects and the limitations of the risk parity strategy. It helps to establish a trust in the author’s firm.
I applaud the AQR philosophy that management costs, particularly in the Hedge Fund universe, are far too high. The current cost structure seems appropriate, but the huge initial investment hurdle is an unassailable entry mountain for most private investors. I hope some group alternatives exist as is often the case.
A major AQR position is for ultra diversification across products, markets, and globally. It is ubiquitous in their document. I completely agree, but that is not a novel investment idea.
AQR talks about the complexity of risk, about its multidimensional nature. Yet when reporting their methodology, they revert to the conventional standard deviation measure of the risk parameter. This defection to the conventional representation has implications further down the road in my review. For now, the AQR document failed to walk the talk.
I was pleased with the ADQ presentation of investment category outcomes from the past 40 years, particularly with the segmentation of their discussions into decades and into different crisis periods. History does matter and informs our decision making.
I applaud ADQ for properly crediting the academic work completed by Harry Markowitz and James Tobin in the 1950s. These are the cornerstones of efficient portfolio construction and the investment separation concepts. Again, these are well established risk control concepts that are taught in every financial college course today. Nothing new here.
Let’s get back to the definition of risk once again. The ADQ team acknowledges standard deviation shortcomings, but uses it throughout the paper. That’s okay, except when displaying the potential benefits of leveraging in the Efficient Frontier curve given as Figure 6. Markowitz and Tobin used standard deviation as the full measure of risk because that was likely their simplified understanding five decades ago. By resorting to that same definition, ADQ understates the risk of Leverage when investing.
Note that the Leveraged portfolio in Figure 6 is still a linear function of Risk. ADQ knows better. See the warnings in their disclaimer section. At one point, they say: “It is also possible to lose more than the initial deposit when trading derivatives or using leverage.” That’s honest, but it is not properly reflected in the linear extrapolation relationship depicted in Figure 6. For the leverage notional depiction, the curve should bend, convex downward. As expected rewards increase, at some point, the risk price tag is likely to become exorbitant. The leveraged risk/reward tradeoff is definitely not linear.
Without leveraging, the standard Risk Parity portfolio is likely to deliver muted returns (perhaps similar to the Permanent Portfolio genre). The commonsense risk/reward investment tradeoff axiom remains intact; higher expected reward means higher risk adventures.
ADQ offers to sweeten the deal by engaging in very active Hedge Fund leveraging techniques, many of which are fairly presented in the paper. These techniques include special forecasting skills, preferential market assessments, and very active, and accurate money management tools. Hedge funds typically operate in this space. ADQ has considerable expertise and experience functioning in this specialized environment. But those operations increase risk; success can never be guaranteed, and risk is not fully represented in the Figure 6 plots.
ADQ has the experienced talent to execute this investment approach. They have been doing it for years. Just recognize, that is a risk mitigation method that degrades in risk control as leverage stretches for higher returns.
Market watchers have long recognized the realities of “fat-tailed” return distributions. About 15 years ago I did personal Monte Carlo computer simulations to inform my retirement decision. I did my own computer programming. Initially, I postulated Bell curve return’s distributions.
To enhance my simulation fidelity, I modified my code to do Bell curve returns when the randomly selected volatility was within a stipulated standard deviation factor, and then defaulted to a power-curve distribution when that standard deviation criteria was violated. The power-curve distribution better models the real world fat=tail return’s distribution.
Of course, my portfolio survival rate declined with the wilder ride that the fat-tails modeling projected. I still retired as planned, but my wife and I decided on a smaller portfolio drawdown rate as a result of those simulations.
We were never happy with the robustness of those simulations because the point of departure from the Bell curve, and the decay exponent in the postulated power-curve distribution were arbitrary. There is a paucity of data in the fat-tail regime. Inputing an exponential decay rate is pure guesswork. Assumptions must always be made in the borderline zone between orderly and unpredictable future market behavior. Luck is important.
I’m sure you made a wise decision in your ADQ investment. I know you do not expect miracles. It’s a nonlinear world.
Best Wishes.