Table 1 – Researches on Price discovery and Volatility spillover futures market Information Efficiency reduces spot price volatility on spot market before and after its introduction Fut
Trang 1Meta-Analysis of Efficiency of Indian Spot and Commodity Futures
Markets
Pankaj Kumar Gupta
Jamia Millia Islamia University, India
Abstract
Examination of market efficiency has conventionally being an area of interest to the market participants, analysts, investors and regulators We find a large number of researches in commodity markets on a global basis covering various aspects of efficiency like macro-economic impact of trading of spot and futures, discovery mechanism of prices, volatility spillover effects In many developing countries including India, the issue of market efficiency has been mind boggling for researchers since research outcomes are confusing making it extremely difficult to derive reliable implications for the market participants and regulators The researchers have used a variety of techniques in statistics and econometrics These include e.g descriptives, F-ratios and various parametric and non-parametric tests The econometric estimations include examination of Casualty, Error correction, Integration, Auto regressions, GARCH models etc
It is seen that generalization of results is a complex and difficult task since the results derived show varying behavior and complexity In Indian markets, our examination of researches reveals that inferences derived therefrom on the issue of efficiency and interrelationships connote a contrasting view It seems difficult to decide whether the operation of commodity derivatives affects the volatility and efficiency of spot markets and also the trading response In addition, the macro-impact of commodity derivative trading is an unresolved issue
We analyze the methodologies used in these researches in Indian and other countries to find out the major causes of contrast in the inferences on selected parameters like selection of exchange or asset (commodity), time frames, statistical or econometric technique used We also analyze the policy responses of the regulators and attempt to suggest a workable solution to solve these problems We derive that Indian commodity markets are inefficient for majority of commodity sets and the policy response is weak, sub-optimal and haphazard
Keywords: Market Efficiency, Price Discovery, Volatility Spillover, Error Correction, Integration
JEL Classification: Q02, G13, E31, G12
1 Introduction
Forecast of Futures prices of traded assets essentially involves the notion of market efficiency In commodity markets, using the time series data, many researchers have examined varying perspectives of market efficiency Fama (1970) has established that growth of commodity futures market is dependent upon the level of market efficiency Efficiency examination essentially involves the analysis of the co-integrating relationships, causality effects and ability of the markets to conform to the forecasts of the selected models Three principle forms of market efficiency are classified by Fama (1991) - weak, semi strong form and strong form The question of efficiency is still unsolved in the large number of studies throughout the world For
Trang 2example Gupta and Mayer (1981) tested semi-strong form by comparing futures market and ARIMA models forecasts and found them to be outperforming Similar result has been obtained by Rausser and Carter (1983) with a caution that “unless the forecast information from the models is sufficient to provide profitable trades, their superior forecasting performance in a statistical sense has no economic significance” Elam and Dixon (1988) reject the validity of results using conventional F tests in a non-stationary price series Maberly (1985) reveal that “the inference that the market is inefficient for the more distant futures contracts is a direct result
of the bias inherent in using OLS to estimate the parameters in models with censored data” Engle and Granger (1987) provide a co-integration based method for efficiency test give the non-stationery nature of time series Allen and Som (1987) research on London rubber market support the hypothesis of weak form efficiency Various researches have been carried out conducted globally to examine commodity futures market efficiency of particularly futures like Canarella and Pollard (1987), Baura (1987), Dickinson and Muragu (1994),
Chan et al (1997), Min et al (1999) for Korea and Taiwan market which establish the weak form of efficiency
Similarly, Groenewold and Kang (1993) establish that Australian market is efficient in semi strong form Yalawar (1988) have used correlation and run test to test the stock market efficiency and found to be efficient Brorsen, Oellermann and Farris (1989) argue that futures trading introduction improves the efficiency of spot market efficiency though increasing the price risk Kaminsky and Kumar (1990) find excess return to be positive for some commodities time horizon being greater than three months Chowdhury (1991) suggest the use of co-integration over conventional methods of testing efficiency of futures markets Studies conducted by
Aulton, Ennew and Rayner (1997) and Kellard et al (1999) respectively show the partial integration and
short-run efficiency of markets respectively But, Andrew and Mathew (2002) using GQARCH-in-mean processes find that markets are unbiased in long run Phukubje and Moholwa (2010) on South African Futures commodity markets and Paschali (2007) on Bulgarian agricultural Commodity Markets during transition show that weak policy interventions results in poor integration between local and international markets with
a functional lacuna
Researches on Indian commodity futures markets show contrasting results Thiripalraju et al (1997) shows
that commodity markets in India are efficient on various parameters like price discovery and inter market feedback Singh (2005) argue that opinions on market efficiency are mixed and vary across commodities Sahi and Raizada (2006) conclude poor price discovery and volume trading impact of futures fueling inflation (in spot market) Bose (2008) find two way price discovery function of spot and futures commodity market, reducing the volatility thus helping the hedging function Contrary results have been indicated by Eswarana and Ramasundaram (2008) Singh, (2009) have realized the “genuine shortcomings accruing due to lack of detailed investigation of seasonality, overlapping data and unspaced observations in examining the efficiency and spill overs”
Goyari and Jena (2010) find the Indian commodity markets to be inefficient in weak form and sufficient opportunities exits to make profits through a structured trade Singh (2010) have shown the persistence of a long-run equilibrium relationship between futures and spot price series of selected commodities
Kaur and Rao (2010), Chakrabarty and Sarkar (2010) find support for market integration that is suitable for hedging However, Dinkar and Nagpal (2011), Ali and Gupta (2011) find the market to be partially efficient Agnihotri and Sharma (2012) argue that quality of market need not to be compromised with separation of contracts It is, therefore, inferred that the issue of co-integration and market efficiency is still unresolved
We therefore find interesting to explore the reasons for these varying results of these researches and possible explanation of the methodological implications For this purpose, we split the issue of market efficiency into three components – (a) Price discovery and Volatility Spill over, (b) Interrelationship between futures and spot markets and (c) Macro economic impact of futures commodity markets We use the published researches on commodity markets with a focus on Indian markets1
1 Research Papers/Articles in various table indicated in bold represent researches on Indian commodity markets
Trang 32 Price Discovery and Volatility Spillover
An important function of commodity futures market is discovery of price that aids the producers to plan their various operational activities starting from production to distribution of commodities Analysis of volatility spillover coupled with price discovery function of market continuously attracts the interest of analysts and investors In spite of similar availability of information to both spot and futures markets the reactions are not identical causing a spillover effect Various researches in India and abroad have been conducted on the examining the issues of price discovery and volatility spillovers Table 1 shows a gist of these researches focusing the research technique used, issues examined and the implications
Table 1 – Researches on Price discovery and Volatility spillover
futures market
Information Efficiency reduces spot price volatility
on spot market before and after its introduction
Futures trading introduction either reduced or did not increase volatility of spot prices
Garbade and Silber
(1983)
Granger Casualty, Co-integration
Impact of Futures market
on spot market
Flow of information from spot to futures market is reverse and important role of liquidity and market size in price discovery
Oellermann et al
(1985)
Granger causality Lead lag relationship
between spot and futures prices
Futures market discover price
model based on prices interactions of informed speculators and hedgers
Opening Futures trading improves risk sharing and reduces price volatility
Oellermann and
Farris (1989) Garbade Silber framework Impact of Futures trading on spot markets Futures market discovers price Bessembinder and
Seguin (1993)
market volatility
Volatility of spot prices has positive relation with unexpected volume and negative relation with the expected open interest Yang and Leatham
(1999)
futures markets
In a search for equilibrium price, futures market implicitly gather more information than available
in the cash markets alone
variable model Impact of futures trading on seasonal price
fluctuations
Futures trading reduced price volatility
countries Strength of the volatility spillovers increased after major
events
discovery function of futures markets
Cash and Futures market co-integration not affected by storage
of traded assets, yet creating a bias in price estimates
Thomas and
Karande (2001) Price dynamics model suggested by Garbade
and Silber (1983)
Effectiveness of Price discovery function of futures markets
Reaction of markets to information altogether varies in price discovery process
Trang 4Assoe (2001) Co-integration Linkage between various
markets
Small and negative mean spillover effects
(1983) model
Effectiveness of Price discovery function of futures markets
Futures role in Price Discovery is not substantial
management Significant Co-integration relationship (a strong long run
relation Raju and Karande
(2003) Granger causality, Co-integration, GARCH Volatility spill over and Price discovery function of
futures markets
Futures markets impact cash market and brings volatility
stabilization of spot prices, inventory and production decisions
“Unnecessary hoarding increase the carrying cost leading to lower responsiveness of inventory to future prices”
Co-integration
Information efficiency and Price discovery function of futures markets in India
Futures market unable to fully incorporate information Bhar and Hamori
(2005)
relationship between volatility and trading volume
Higher order lagged returns affect trading volume
Chopra and Blesser
(2005) Co-integration, error correction models Price discovery function in cash markets Cash contracts and first distant futures contracts behavior shows
inefficiency of market
markets
Futures trading ineffective in reducing seasonal price volatilities
Yang et al (2005) Generalized forecast
error variance decomposition Granger Causality
Lead-lag relationships between futures trading and spot prices
Unidirectional impact on spot prices, “weak causal feedback between open interest and cash price volatility”
Slade and Thille
(2006) Descriptive measures Levels and volatilities of the spot prices Relationship between trading volume and price instability is
positive
markets
No change in volatility Qing-fu and
Jin-qing(2006)
Johansen Co-integration, VECM, Bivariate EGARCH
Price discovery function of futures
Significant bi-directional information flows Praveen and
Sudhakar (2006)
Commodity futures market and stock market and
Unidirectional impact
Bryant et al (2006) Co-integration
framework
Generalized theory of normal backwardation
Rejected the hypothesis Kiran and
Mukhopadhyay
(2007)
GARCH on intra-day Volatility spillover from the
US to India
Established, Basic ARMA-GARCH specification outperforms MGARCH Piyamas and
Pavabutr (2007)
futures contracts
Partial performance Nath and
Lingareddy (2008)
Hodrick-Prescott filter (1997)
Trading impact of futures markets (India)
Futures do not increase cash price volatility
Trang 5Biswas (2009) Cointegration and
Error correction dynamics
Price discovery function of futures contracts
Co-integrated and long-run relationship established
Forecast error variance decompositions, Impulse response
Linkages between futures trading and volatility of spot market
Lagged unexpected volatility causes spot price volatility for all commodities
futures contracts
Efficient in price discovery Maitra and
Narayanan (2010)
Linear regression forecasting
Forecast performance of volatility
Found some evidence
response
Futures and Spot price convergence
Causality is bi-directional and spot market for selected commodity flexible
BEKK-GARCH and CCC-GARCH
Volatility and hedging behavior of selected commodity futures indices
Models effective in spot price discovery
Joseph and Sajan
(2010)
Mean, Deviations, Correlations
Futures trading effectiveness
Markets offers profitable investment opportunities Dash and Andrews
(2010)
futures prices
Price discovery mechanism is quite effective in general Chakravarty and
Ghosh (2010)
Bivariate EGARCH, Parkinson(1980) range based estimator
Volatility using intra day interval data
Evidence of intra day periodicity, seasonality, and the net inverse relation between time to maturity and realized volatility
Debasish and
Kushankur (2011) GARCH, EGARCH CGARCH, MGARCH,
Diagonal VECH, BEKK
Volatility and its spill over effects Bi-directional spill over captured under GARCH and unidirectional
spill over found under EGARCH
Co-integration Price discovery function Futures market dominates price discovery
model Price discovery mechanism in commodities and assess
the long-term trends in their prices
Model robust to capture trends
Chauhan, Singh and
Arora (2013)
discovery
Information flow from futures market to spot market
Masood and
Chary(2016)
Variance Ratios, Non-parametric tests
Growth of Commodity Futures Market
Volume and Value relationship is linear
We derive from the literature is that futures and spot markets absorb the same set of information in an identical period leading to discovery of price and spillover effects However, the conflict is the point of reaction i.e flowing from spot to futures or futures to spot We have further investigated these researches, particularity
on Indian commodity markets Our examination indicates that the research inferences differ mainly because
of the data used for analysis The data available on commodity exchanges – MCX, NCDEX, MCX, ICX differ
significantly with respect to the time frequency, price-volume, and high low statistics On some exchanges the data is not continuous which raises questions on the applicability of an appropriate times series method We
also raise questions on use of econometric techniques A vast number of studies have used the GARCH model
during the periods when the market conditions were not relatively stable, even though the model captures
time varying variances We find instances of fat tails in the price distribution of some commodities that limit the
application of GARCH Use of Johansen Co-integration test is appropriate compared to Engle-Granger (EG)
Trang 6method since EG captures only a single set of co-integrating relations However, Johansen Co-integration test requires a stationery filter, which many are violated for a significant number of commodities in India There
is an ongoing debate on the use of VAR vs VECM VECM is able to explain the price discovery built in
short-run dynamics framework The inherent requirements of a particular model when applied to a given price series of
commodity in different time periods may produce differing results Therefore, it becomes difficult to generalize the
results of researches We also find that the commodities as per their nature be classified as – agro type (immediate consumption/intermediate production), asset type (gold/silver), industrial type (metals) However, there exists a relationship for the same commodity classified in two sets For example, silver is for industrial as well as household consumption Business cycles, festivals and hedging needs of economic participants would altogether affect the price series Consequentially, the results of price discovery and spillovers would be different in different circumstances These may possible explain the confusion between the researchers
3 Spot and Future Markets Integration
We further explore the relationship between futures and spot markets used to test the notion of efficiency under a distinct framework The selected list of researches on these aspects is given in Table 2
Table 2 – Researches on Spot and Future Markets Integration
relationships
Long-run relationships found, cash markets lead futures markets
GARCH
market
Futures market found to be efficient
Bessler and Covey
(1991)
relationships for slaughter
Found evidence
lag regression
Cash-futures price relationships
Trading intensity affected lead lag relation-no convincing evidence Fortenbery and
Zapata (1993) Co-integration Interest rate in describing price discovery Interest rate as an explanatory variable useful in explaining
relationship Baharumshah and
Habibullah (1994)
among prices in six Malaysian markets
Markets in Malaysia were highly integrated
Karbuz and Jumah
(1995)
between spot and futures
Prices of commodities tend to move together in the long run Herrero and John
(1997)
Co-integration, Granger Causality
Stability of long-run co-movement between commodity prices of world and UK retail
No casualty found
Fortenberry and
Zapata (1997) Co-integration Lead-lag relationship between spot and futures in
US
Partial evidence of integration
Fung and Patterson
volatility and open interest
Open interest and volume are not endogenously determined
Trang 7Silvapulle and
Moosa (2000)
Non-linear causality test Bivariate VAR
Price volume relationship
in futures market
Linear causality from volume to price
Maynard et al (2001) Short-run analysis
based on Two-sided distributed lag model
Performance of Minneapolis Grain Exchange futures contracts with thin volumes
Co-integration found in only one variety(commodity class)
McMillan and
Speight (2002)
Sequential Information arrival Hypothesis and Distribution
Hypothesis , VAR
Relationship between volume and absolute return
From volumes to absolute returns,
no apparent causality, but some cases of causality flowing from return to volume seen
Asche and
Guttormsen (2002)
between spot and futures
Futures lead cash spot prices and distant futures lead near futures
market depth, trading volumes and absolute returns
Lack of efficient and modern infrastructure facilities, existence
of the gray market and lack of participation in the futures markets
modeling, OLS, two stage least squares regression
Lead-lag relationship between futures and spot prices of stock indices
Futures react faster than the spot market in disseminating
information
causality, VAR Relationship between Tokyo commodity futures
price changes and volumes
Volume contains no information
to forecast return
Chen and Firth
(2005)
Chinese commodity futures trading volume and returns
Existence of contemporaneous correlation between trading and volumes and absolute returns ruled out
Chinese commodity futures volume, daily volatility and returns
Relationship of volatility with volume is positive and with open interest is negative
Yang et al (2005) Generalized forecast
error variance decompositions Granger causality
Relationship between commodity futures volume and open interest
Weak causal feedback between volatility of cash prices and open interest
world cash prices for exported sugar and New York sugar futures
Causality in one direction from future price to cash but not vice versa
of spot and future prices Long-run equilibrium mechanism exists
Mattos and Garcia
(2004)
Brazilian agricultural market future and spot prices
Long-term equilibrium relationships between spot and future prices exists due to higher volume of trading
Casualty
Lead lag relationship between spot and futures trading
Imperfections in Indian commodity markets
Granger causality, VECM
Causality and speed of adjustment to deviations
in long run equilibrium
No single country is completely exogenous and many countries GSP prices are interlinked to some extent
Trang 8Hadsell (2006) Threshold ARCH Relationship between
trading volume and price volatility
Traders react asymmetrically to new information
Babula et al (2006) Co-integrated VAR
based Johansen and Juselius methodology
Relationship between price volatility and trading volume and
Policy relevant elasticities important in US markets Azizan, Ahmad and
Shannon (2007)
Bivariate ARMA-EGARCH model
Futures-cash market relationship (Malaysia)
“Information transmission process at mean and volatility level between cash and futures”
Casualty
Cash-futures price relationships
Evidence of co-integration and operational efficiency, though at a slower rate
Iyer and Mehta
Roy and Kumar
(2007) Johansen Co- integration,
Garbade-Silber (1983) model
Lead-lag relationship between futures and spot prices and hedging effectiveness
Partial evidence
Kumar, Singh and
Pandey (2008) Co-integration, Casualty Volatility, Risk premium and seasonality Risk return relationship, Seasonality in risk and return
established
Nath and
Lingareddy (2008)
Granger causality, Correlations, Basic regression with dummies, GARCH
Futures-Spot Integration Co-integration observed between
China and U.S.A cotton futures
Casualty Market integration with global Spot markets in India are co- integrated with global
Long and Lei (2008) Co-integration,
Granger causality, Residue analysis, IRF, VECM
Commodity prices relationships at exchanges
Co-integrated
Bekiros and Diks
(2008)
GARCH BEKK model Causal linkages between
spot and futures of Linear and nonlinear type
Evidence found
on market integration Partial evidence
Raveendran et al
(2010) VECM Transmission of future price to spot price Unidirectional flow from futures to spot Bhardwaj and
Vasisht (2009) Co-integration, Granger Causality the Integration of futures and spot market Price discovery in each contract is unidirectional
Elumalai et al (2009) Johansen Cointegration
Granger causality Long-term equilibrium relationship between spot
and futures
Relationship found
competing domestic commodity futures markets
Partial evidence
Causality Unrelated regression
Role of commodity futures with thin trading in prices determination in physical market
Little evidence that futures price serves as reference price
Trang 9Iyer and Pillai (2010) TVAR Futures markets role in the
price discovery process
Convergence rate of information
is slow specifically observed in non-expiration weeks
Vasisht and
Bhardwaj (2010) Johansen Cointegration tests,
Granger causality
Volatility of agricultural prices Co-integration evidence found but unidirectional causality from
futures to spot markets
relationship post migration
of Malaysian crude palm oil futures
Persistence of Volatility higher marginally in automated trading system compared to relative to the open outcry system Batten, Ciner, and
Lucey (2010)
for precious metals
“Precious metals are too distinct
to be considered a single asset class, or represented by a single index”
Saravanan and
Malabika (2010) VECM, GARCH model Role of futures on underlying spot market Partial evidence
Xaviour and Mathew
(2010)
Palanichamy et al
(2010) Cointegration , Granger Causality
tests
Long-run equilibrium
Vasisht and
Bhardwaj (2010) Granger causality Bivariate relationship between spot and future
market
Evidence found
Hernandez and
Torero (2010) Linear and nonlinear (nonparametric)
causality tests
Relationship dynamics between spot and futures prices of agricultural commodities
Futures markets generally discover spot prices
Jayagurunathan et
Error Correction Models
Co-integrations, price discovery process “Spot markets marginally leads futures and spot prices tend to
discover new information more rapidly than future prices” Chakravarty and
Ghosh (2010) Standard GARCH model Effect of commodity futures trading on spot
prices
Positive effect of future price movements
Mukerjee (2011) Multiple regressions,
VAR, Granger Causality, GARCH
Impact of futures trading
on spot markets Significant discovery of price and risk management
capabilities
M-GARCH with error correction model
Performance of various hedge ratios “Dynamic M-GARCH model hedging strategy performs best
in reducing the conditional variance of the hedged portfolio” Kumar and Pandey
(2011a)
Johansen’s Cointegration Granger causality Variance decomposition GARCH (BEKK)
Cross market linkages- Nine commodities futures
in India with those outside India
World markets have a significant unidirectional impact on markets
in India
Kumar and Pandey
(2011b) GARCH, Granger Causality, variance
decomposition, IRF
Relationship between trading volume, volatility and open interest
Overnight volatility impact the trading volume, open interest not affected
Srinivasan (2012) Johansen
Cointegration, VECM, Bivariate EGARCH
Price discovery process and volatility spillovers Evidence of Flow of information from spot to futures
Trang 10Haq and Rao(2014) Johansen
Co-integration and VECM
Commodity market efficiency
Only Long-run Efficiency observed
Gupta, Chaudhary
and Agarwal(2017) VECM, V-MGARCH Hedging Effectiveness Distant Futures have better hedge ratio
Going by the notion of efficiency, when the phenomenon of arbitrage and information flow distortion occurs, the market is said to be inefficient High volumes guide futures market of the commodities when large players can use muscle power to drive the Indian market by taking simultaneous position in futures and spot markets and playing an arbitrage The flow of information from futures to spot is obvious and is an auto
process, yet we find instances of backwardation and contango violated over fairly large time periods We also blame
the large Foreign Institutional Investors (FII) acting as fly by night operators both in the commodity and securities markets We generalize by saying that the Indian commodity market is inefficient in semi strong form but sometimes for selected data groups typically show efficiency in short runs
4 Macro-Economic Impacts of Commodity Markets
Researchers have extensively used a variety of integration and vector type models to investigate the impact
of commodity trading on various macro economic measures particularly inflation In an Indian context, the most common measure of inflation is the change in the whole price index (WPI) Expectation hypothesis explains that prices in futures markets are unbiased expectations of series of future spot prices Therefore, demand-supply effect on prices of commodities in futures markets is obvious The series of futures prices convey trading information to the market players Given the inefficiency of information dissemination, the price arbitrage can have a devastating impact An important concern to the policy makers is the impact of the market behavior on the macro economic variables India, in the last decade has witnessed serious demand-supply gaps as well as price distortions in markets, which have raised important concerns like rising prices Inflation has become more important after the global financial crisis that made the markets more volatile Table
3 shows the summary of the researches mainly carried out on Indian commodity markets
Table 3 - Researches on Macro-economic Impacts of Commodity Markets
and the real return to forward speculation
Conditional covariance consistent with the predictions of the consumption-beta model Becker and Finnerty
(2000)
inflation hedge
Portfolio comprising of long commodity futures contracts improves risk and return performance when combined with bonds and stocks Jensen, Mercer and
Johnson (2002)
Co-integration Benefits of diversification
derived from inclusion of commodity futures to a traditional portfolio
Commodity future sustainability enhances portfolio performance
commodities in Asian neighbors on Indian markets
Partial Evidence
Gorton and Horst (2006) Co-integration Correlation between traded
commodity futures and other assets classes
Commodity futures correlate positively to inflation and its changes