Mar 30, 2015
Kenneth R. Zimmerman, Ph.D. Senior Analyst Oregon Public Utility Commission
Even the weakest version of EMH asserts that prices on traded assets (e.g., stocks, bonds, or property) already reflect all past publicly available information. The semi-strong version asserts that prices reflect all publicly available information and instantly change to reflect new information.
Its proponents claim that because of EMH it is not possible to consistently outperform the market by using any information that the market already has, except through insider trading or other informational subterfuge
In the EMH information is defined as anything that may affect prices that is unknowable in the present and thus appears randomly in the future. Markets are rational because of EMH
The results in markets are often summarized by the phrase “random walk” to show more clearly that rational markets, EMH markets, cannot be outguessed or manipulated by using secret or limited information
June 2010 2SASE 2010 Meeting Philadelphia
As described above both the wholesale electricity and natural gas markets created by FERC and the retail electricity markets created by states (but dependent on FERC wholesale constructions) use EMH as a foundation
In that case information about electricity prices in these markets should be fully available, transparent, and reliable. Also with EMH as a foundation it should not be possible for any agent to manipulate prices in these markets except through the use of insider information
Similarly, states generally assumed in creating retail electricity markets (and the few natural gas markets constructed) that EMH was how markets were supposed to and did operate
June 2010 3SASE 2010 Meeting Philadelphia
But EMH appears not to have lived up to its expectations Almost since the outset lack of clear, transparent, and reliable
information about prices and the data and decisions that underlie prices has been a topic of concern in the wholesale and retail electricity and natural gas markets
Accusations about manipulation of electricity and natural gas prices by various markets agents have been the norm also
With the exception of clearly visible manipulation of prices by state legislatures, FERC, RTOs, and the US Congress, there has been little effort to identify or prove manipulation by agents selling and purchasing natural gas or electricity. In part this lack of effort is a result of the difficulty in clearly identifying actions that are and are not manipulative agents’ intentions in taking actions
Clearly the concerns about information uncertainty and reliability, and price manipulation cannot be resolved or even fully explained through laws, orders, policy statements, or workshops
June 2010 4SASE 2010 Meeting Philadelphia
It appears neither policy makers nor economists understand wholesale or retail electricity and natural gas markets and their workings
Both appear to assume that EMH is valid and controls the functioning of these markets
But if EMH does not explain these markets what does? This is a complicated question
This paper presents a short overview of some of the efforts of FERC, RTOs, states, and Congress to answer this question, mostly without success
Giving up the belief in EMH is certainly a move in the right direction. It would clear the path for detailed descriptions of how these markets function, what interests actors pursue, and how actors calculate to obtain their interests
Regulators and policy makers with this agenda are both more effective and more humble. Both make them more effective regulators and make the markets they oversee more likely to create prices that satisfy the interests of all market participants
June 2010 5SASE 2010 Meeting Philadelphia