Testing Persistence of WTI and Brent Long-run Relationship ...
Determinants of the WTI-Brent Spread Revisited...Re-examination of WTI-Brent price spreads on a...
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Determinants of the WTI-Brent Spread Revisited:
Before and after the Structural Break
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited1
(Work in progress)
Andreas Rathgeber* and Jerome Geyer-Klingeberg*
Dauphine Université Paris, 16th March 2018
*Institute of Materials Resource Management
University of Augsburg
Germany
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Development of WTI and Brent crude oil
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
Source: U.S. Energy Information Administration
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Review of the literature
Structural breaks in WTI-Brent price spread
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
Determinants of WTI-Brent spread
Authors Sample period Structural break test Identified breaks
Büyüksahin et al. (2013) 2000:06 – 2012:07 Chow (1960) 2008:11, 2010:12
Aruga (2015) 2001:01 – 2014:05 Bai and Perron (1998) 2003:01, 2005:01, 2007:01,
2009:02, 2011:02
Chen et al. (2015) 1988:01 – 2014:12 Leybourne et al. (2007) 2010:04
Li et al. (2015) 2004:01 – 2013:12 Hansen (1997) 2010:01
Liu et al. (2016) 2004:01 – 2010:12 Bai and Perron (1998) 2010:12
Ye and Karali (2016) 1993:12 – 2016:04 Bai and Perron (1998) 2005:05, 2010:12, 2013:04
Authors Sample period Methodology Main spread determinants
Milonas and Henker (2010) 1991:02 – 1996:01 OLS regression Convenience yield
Büyüksahin et al. (2013) 2004:04 – 2012:04 ARDL U.S. business climate, storage problems
in Cushing, open interest, position of
futures traders
Re-examination of WTI-Brent price spreads on a daily data set between
1995:01 and 2014:07 using autoregressive distributed lag models (ARDL)
Advanced tests for detection of structural breaks
Analysis of change in the spread determinants after structural break(s)
Comprehensive investigation of convenience yield as proxy for crude oil
inventories
Examination of the balancing mechanism between spot and futures market
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Contribution
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
𝑃𝑡𝑊𝑇𝐼: WTI opening price
𝑃𝑡𝐵𝑟𝑒𝑛𝑡: Brent closing price
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Spread calculation and convenience yield
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
𝑆𝑃𝑅𝑡 = 𝑆𝑡𝑊𝑇𝐼 − 𝑆𝑡
𝐵𝑟𝑒𝑛𝑡 𝑆𝑡𝐵𝑟𝑒𝑛𝑡Normalized WTI-Brent spread:
Convenience yield: 𝐶𝑌𝑡,𝑇 = 𝑅𝑡,𝑇 + 𝐶𝑡,𝑇 −1
𝑇 − 𝑡ln 𝐹𝑡,𝑇 − ln 𝑃𝑡
𝑃𝑡,𝑇: Three month U.S. treasury bill
𝐶𝑡,𝑇: Storage costs ($0.40 according to Ederington et al. 2012)
𝐹𝑡,𝑇: Three month crude oil futures price
𝑃𝑡: 𝑃𝑡𝑊𝑇𝐼 and 𝑃𝑡
𝐵𝑟𝑒𝑛𝑡
Three step estimation procedure following term structure of yield curves (Martellini
2003):
1. Calculation of 𝐶𝑌𝑡,𝑇 for different maturities
2. Interpolation of all data points using a cubic spline function
3. Evaluation of the spline function at the desired maturity
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Data (I/II)
Daily data set from 01/01/1995 through 23/07/2017
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
Variable Definition Source
𝑃𝑊𝑇𝐼 Western Texas Intermediate opening spot price (U.S. dollars per barrel) Datastream
𝑃𝐵𝑟𝑒𝑛𝑡 UK Brent nominal closing spot price (U.S. dollars per barrel) Bloomberg
𝐹𝑊𝑇𝐼 WTI opening futures crude oil price (U.S. dollars), 3 months to maturity NYMEX
𝐹𝐵𝑟𝑒𝑛𝑡 Brent closing futures crude oil price (U.S. dollars), 3 months to maturity ICE
𝑇𝑆𝑊𝑇𝐼 Term spread, defined as 𝐹𝑊𝑇𝐼 − 𝑃𝑊𝑇𝐼 Own calculation
𝑇𝑆𝐵𝑟𝑒𝑛𝑡 Term spread, defined as 𝐹𝐵𝑟𝑒𝑛𝑡 − 𝑃𝐵𝑟𝑒𝑛𝑡 Own calculation
𝑅𝐹 Three months U.S. treasury yield on actively traded non-inflation-indexed issues,
adjusted to constant maturity
Federal Reserve
𝑉𝐿𝑊𝑇𝐼 Aggregate trading volume for WTI futures contracts NYMEX
𝑉𝐿𝐵𝑟𝑒𝑛𝑡 Aggregate trading volume for Brent futures contracts ICE
𝑂𝐼𝑊𝑇𝐼 Aggregate open interest for WTI futures contracts NYMEX
𝑂𝐼𝐵𝑟𝑒𝑛𝑡 Aggregate open interest for Brent futures contracts ICE
𝐵𝐷 Baltic dry index pre-multiplied by the sign of the WTI-Brent spread Baltic Exchange
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Data (II/II)
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
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Summary statistics
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
Mean Median Std. Dev. Min Max N
𝑆𝑃𝑅𝑆𝑝𝑜𝑡 0.0160 0.0272 0.0852 -0.2498 0.3470 4708
𝑆𝑃𝑅𝐹𝑢𝑡𝑢𝑟𝑒 0.0175 0.0324 0.0725 -0.2297 0.2298 4708
𝐶𝑌𝑊𝑇𝐼 0.1615 0.1374 0.2288 -1.3395 1.2963 4708
𝐶𝑌𝐵𝑟𝑒𝑛𝑡 0.1791 0.1406 0.1847 -0.4825 1.1224 4708
𝑇𝑆𝑊𝑇𝐼 0.2501 0.1500 2.0408 -13.8300 15.2000 4708
𝑇𝑆𝐵𝑟𝑒𝑛𝑡 -0.0613 -0.2700 1.5073 -5.2900 8.1100 4708
𝑉𝐿𝑊𝑇𝐼 0.0005 0.0025 0.2943 -2.6140 2.9832 4708
𝑉𝐿𝐵𝑟𝑒𝑛𝑡 0.0005 0.0010 0.3376 -2.2412 2.9857 4708
𝑂𝐼𝑊𝑇𝐼 0.0003 0.0015 0.0188 -0.1899 0.2341 4708
𝑂𝐼𝐵𝑟𝑒𝑛𝑡 0.0004 0.0024 0.0335 -0.4792 0.4658 4708
𝐵𝐷 -0.0002 0.0000 0.0178 -0.2052 0.1464 4708
𝑇𝑅 0.0227 0 0.1490 0 1 4708
𝐻𝑅 0.0042 0 0.0650 0 1 4708
𝑆𝑇𝑈𝑆 0.0002 0.0007 0.0140 -0.1080 0.0942 4708
𝑆𝑇𝐸𝑈 0.0001 0.0006 0.0119 -0.0679 0.0912 4708
𝐻𝑇 0.5346 0.0000 1.4160 -3.9125 7.5875 4708
𝐶𝐿 1.2797 0.0000 3.1998 -12.2250 15.4896 4708
Notes: This table presents summary statistics for the full sample period. Variable definitions can be obtained from Table 1.
***, **, * denote statistical significance at the 1%, 5% or 10% level.
1. Detection of structural break in WTI-Brent spread
Chow-test, CUSUM, CUSUMQ, Andrews test, Hansen test
Result: 3 breaks (Only one break is always significant at 5% level)
2. Combined tests for unit root and structural break
Bai/Perron (2003), Busseti/Harvey (1998), Harvey/Mills (2001)
Lee/Strazicich(2001), Perron (1997), Zivot/Andrews (1992) and BIC
Several Break types (Shift, Crash, Trend and combinations)
Up to 5 breakpoints
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited9
Time Series Analysis - Structural Break
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited10
Histogram of Combined Unit Root and
Structural Break Tests
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited11
Results of Lee/Strazicich (2001) test
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited12
Breakpoint - Economic evaluation
Absolute low of U.S. crude oil production: Oct 2008, Jan 2008
Source: U.S. Energy Information Administration
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited13
Cointegration analysis of WTI and Brent
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited14
Response of WTI (Brent) oil price
to Cholesky One S.D. Brent (WTI) Innovation
Estimated in first differences, 𝑉𝐴𝑅(2, 𝑘)with 𝑘 ∈ {1,2}
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited15
Unit Root Tests
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ARDL model
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
ARDL 𝑝, 𝑞1, … , 𝑞𝑛 in following unrestricted error correction (ECM)
∆𝑆𝑃𝑅𝑡 = 𝑎0 + 𝑎1𝑡 +
𝑖=1
𝑝−1
𝜓1,𝑖∆𝑆𝑃𝑅𝑡−𝑖 +
𝑗=1
𝑛
𝑖=0
𝑞𝑗−1
𝜓𝑗+1,𝑖∆𝑋𝑗,𝑡−𝑖 + 𝜆1𝑆𝑃𝑅𝑡−1 +
𝑗=1
𝑛
𝜆𝑗+1𝑋𝑗,𝑡−1 +
𝑘=1
𝑚
𝛿𝑘𝑍𝑘,𝑡 +𝑢𝑡
𝑎0 is the drift component
𝑡 = max 𝑝, 𝑞1, … , 𝑞𝑛 , … , 𝑇 is the time trend component
𝑋 = [𝐶𝑌𝑊𝑇𝐼, 𝐶𝑌𝐵𝑟𝑒𝑛𝑡, 𝑉𝐿𝑊𝑇𝐼, 𝑉𝐿𝐵𝑟𝑒𝑛𝑡, 𝑂𝐼𝑊𝑇𝐼, 𝑂𝐼𝐵𝑟𝑒𝑛𝑡, 𝐵𝐷, 𝑆𝑇𝑈𝑆, 𝑆𝑇𝐸𝑈]
𝑍 = [𝐻𝑇, 𝐶𝐿, 𝑇𝑅, 𝐻𝑅, 𝑆𝐵]
𝑢𝑡 is the white noise error term
𝜓1,…,𝜓𝑛 symbolize the error correction dynamics
𝜆1, … , 𝜆𝑛 represent the long-run relationship
ARDL bounds test: 𝐻0𝐹: 𝜆1 = ⋯ = 𝜆𝑛+1, using critical values by Pesaran et al. (2001)
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ARDL results – Bounds test
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
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ARDL results – Error correction term
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
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ARDL results – Long-run elasticities (I/II)
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
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ARDL results – Long-run elasticities (II/II)
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
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Concluding remarks
Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited
WTI-Brent spread shows significant structural change in 2010
The convenience yield, as proxy for crude oil inventories, is the most
important spread determinant
The impact of the convenience yield changed since the break in 2010
Also the trading volume in WTI futures markets as well as the economic
situation and temperature differences between the U.S. and Europe drive
the size of the WTI-Brent spread.
The importance of trading volume in WTI futures is reduced.
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References
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References
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Andreas Rathgeber | Dauphine Université Paris | Determinants of WTI-Brent Spread Revisited