Systematic Features of High-Frequency Volatility in Australian Electricity Markets: Intraday Patterns,Information Arrival and Calendar Effects

Abstract

This paper investigates the intraday price volatility process in four Australian wholesale electricity markets; namely New South Wales, Queensland, South Australia and Victoria. The data set consists of half-hourly electricity prices and demand volumes over the period January 1, 2002 to June 1, 2003. A range of processes including GARCH, RiskMetrics, normal Asymmetric Power ARCH or APARCH, Student APARCH and skewed Student APARCH are used to model the time-varying variance in prices and the inclusion of news arrival as proxied by the contemporaneous volume of demand, time-of-day, day-of-week and month-of-year effects as exogenous explanatory variables. The skewed Student APARCH model, which takes account of right skewed and fat tailed characteristics, produces the best results in all four markets. The results indicate significant innovation (ARCH effects) and volatility (GARCH effects) spillovers in the conditional standard deviation equation, even with market and calendar effects included. Intraday prices also exhibit significant asymmetric responses of volatility to the flow of information.

Keywords

Electricity markets GARCH APARCH Intraday price volatility Calendar effects Australia Information arrival

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References

Alexander

(2001). Market Models. Wiley.

Andersen

Bollerslev

(1997). “Intra-day periodicity and volatility persistence in financial markets.” Journal of Empirical Finance 4(1): 115-158.

Andersen

Bollerslev

(1998). “Deutsche mark-dollar volatility: Intrraday activity patterns macroeconomic announcements, and long run dependencies.” Journal of Finance 53(1): 219-265.

Andersen

T.G.

(1996). “Return volatility and trading volume: An information flow interpretation of stochastic volatility.” Journal of Finance 51(1): 169-204.

Bauwens

Giot

(2001). Econometric modeling of stock market intraday activity. Kluwer.

Bera

A.K.

Higgins

M.L.

(1993). “ARCH models: properties, estimation and testing.” Journal of Economic Surveys 7(4): 305-366.

Bollerslev

(1986). “Generalised autoregressive condition heteroskedasticity.” Journal of Econometrics 31(3): 307-327.

Bollerslev

Chou

R.Y.

Kroner

K.F.

(1992). “ARCH modeling in finance: a review of the theory and empirical evidence.” Journal of Econometrics 52(1): 5-59.

De Vany

A.S.

Walls

W.D.

(1999a). “Cointegration analysis of spot electricity prices: insights on transmission efficiency in the western US.” Energy Economics 21(3): 435-448.

10.

De Vany

A.S.

Walls

W.D.

(1999b). “Price dynamics in a network of decentralized power markets.” Journal of Regulatory Economics 15(2): 123-140.

11.

Dickson

Warr

(2000). “Profile of the Australian Electricity Industry.” Australian Bureau of Agricultural and Resource Economics (ABARE), Research Report No. 2000.7, Canberra.

12.

Ding

Granger

C.W.J.

Engle

R.F.

(1993). “A long memory property of stock market returns and a new model.” Journal of Empirical Finance 1(1): 83-106.

13.

Engle

R.F.

(1982). “Autoregressive conditional heteroskedasticity with estimates of the variance of UK inflation.” Econometrica 50(4): 987-1008.

14.

Engle

R.F.

V.K.

(1993). “Measuring and testing the impact of news on volatility.” Journal of Finance 48(5): 1749-1778.

15.

Escribano

Pena

J.I.

Villaplana

(2002). “Modeling electricity prices: International evidence.” Working paper 02-27, Economics Series 08, Departamento de Econom^a, Universidad Carlos III de Madrid.

16.

Foster

(1995). “Volume volatility relationships for crude oil futures markets.” Journal of Futures Markets 15(8): 929-951.

17.

Giot

Laurent

(2003a). “Market risk in commodity markets: A VaR approach.” Energy Economics 25(5): 435-457.

18.

Giot

Laurent

(2003b). “Value-at-risk for long and short trading positions.” Journal of Applied Econometrics 18(6): 641-664.

19.

Hadsell

Marathe

Shawky

H.A.

(2004). “Estimating the volatility of wholesale electricity spot prices in the US.” Energy Journal 25(4): 23-40.

20.

Herbert

(2002). “Power prices today: Growing more unpredictable.” Public Utilities Fortnightly 140(18): 28-35.

21.

International Energy Agency (2001). Energy Policies of IEA Countries: Australia 2001 Review, Organization for Economic Cooperation and Development (OECD), Paris.

22.

Lambert

Laurent

(2001). “Modeling financial time series using GARCH-type models and a skewed Student density.” Mimeo, Universite de Liege.

23.

Lamoureux

Lastrapes

(1990). “Heteroskedasticity in stock return data: Volume verses GARCH effects.” Journal of Finance 45(1): 221-229.

24.

Laurent

(2004). “Analytical derivates of the APARCH model.” Computational Economics 24(1): 51-57.

25.

Laurent

Peters

J.P.

(2002). “G@ARCH 2.2: An Ox package for estimating and forecasting various ARCH models.” Journal of Economic Surveys 16(3): 447-485.

26.

Lucia

J.J.

Schwartz

E.S.

(2001). “Electricity Prices and Power Derivatives: Evidence for the Nordic Power Exchange.” University of California Los Angeles Working Paper, Los Angeles.

27.

National Electricity Market Management Company Limited (2001). An Introduction to Australia's National Electricity Market, NEMMCO, Melbourne.

28.

National Electricity Market Management Company Limited (2003). WWW site: <http://www. nemmco.com.au/>. Accessed August 2003.

29.

Newbery

D.M.

(1995). “Power markets and market power.” Energy Journal 16(3): 39-66.

30.

Pagan

(1996). “The econometrics of financial markets.” Journal of Empirical Finance 3(1): 15-102.

31.

Rahman

Lee

C.F.

Ang

K.P.

(2002). “Intraday return volatility process: Evidence from NASDAQ stocks.” Review of Quantitative Finance and Accounting 19(1): 155-180.

32.

Robinson

(2000). “Electricity pool series: a case study in non-linear time series modeling.” Applied Economics 32(5): 527-532.

33.

Robinson

Baniak

(2002). “The volatility of prices in the English and Welsh electricity pool.” Applied Economics 34(12): 1487-1495.

34.

Robinson

T.A.

Taylor

M.P.

(1998a). “Regulatory uncertainty and the volatility of regional electricity company share prices: The economic consequence of Professor Littlechild.” Bulletin of Economic Research 50(1): 37-44.

35.

Robinson

T.A.

Taylor

M.P.

(1998b). “The effects of regulation and regulatory risk in the UK electricity distribution industry.” Annals of Public and Cooperative Economics 69(3): 331-346.

36.

Schwert

(1990). “Stock volatility and the crash of ’87.” Review of Financial Studies 3(1): 77102.

37.

Smith

(2003). “Leading the news: Surplus of electricity may persist at least until 2005.” Wall Street Journal 12 February, A3.

38.

Solibakke

(2002). “Efficient estimated mean and volatility characteristics for the Nordic spot electricity power market.” International Journal of Business 7(2): 17-35.

39.

Taylor

(1986). Modeling Financial Time Series. Wiley.

40.

Walls

W.D.

(1999). “Volatility, volume and maturity in electricity futures.” Applied Financial Economics 9(3): 283-287.

41.

Wang

Yau

(2000). “Trading volume, bid-ask spread, and price volatility in future markets.” Journal of Futures Markets 20(10): 943-970.

42.

Wolak

F.A.

(2000). “Market design and price behavior in restructured electricity markets: An international comparison.” NBER-East Asia Seminar on Economics, vol. 8. Chicago and London: University of Chicago Press.

43.

Worthington

A.C.

Kay-Spratley

Higgs

(2005). “Transmission of prices and price volatility in Australian electricity spot markets: A multivariate GARCH analysis.” Energy Economics, 27(2): 337-350.