Benoît Sévi

Volatility Transmission and Volatility Impulse Response Functions in European Electricity Forward Markets

Using daily data from March 2001 to June 2005, we estimate a VAR-BEKK model and find evidence of return and volatility spillovers between the German, the Dutch and the British forward electricity markets. We apply Hafner and Herwartz [2006, Journal of International Money and Finance 25, 719-740] Volatility Impulse Response Function(VIRF) to quantify the impact of shock on expected conditional volatility. We observe that a shock has a high positive impact only if its size is large compared to the current level of volatility. The impact of shocks are usually not persistent, which may be an indication of market efficiency. Finally, we estimate the density of the VIRF at different forecast horizon. These fitted distributions are asymmetric and show that extreme events are possible even if their probability is low. These results have interesting implications for market participants whose risk management policy is based on option prices which themselves depend on the volatility level.

The newsvendor problem under multiplicative background risk

This note studies the single-period newsvendor problem when the newsvendor faces a multiplicative neutral independent background risk in an expected utility framework. It is shown that multiplicative risk vulnerability is a sufficient condition to guarantee a decrease in the optimal order. A weaker sufficient condition which has more interpretability is also provided and discussed. This result sheds light on situations where exchange, tax or inflation rates risks, which apply multiplicatively to the final wealth, are at work.

Jump-robust estimation of realized volatility in the EU Emission Trading Scheme

With the increased availability of high-frequency financial market data in recent years, the extraction of “realized” volatility (from intraday squared returns) has led to numerous theoretical developments and empirical applications for a wide range of equity and commodity markets. This paper documents the measure of realized volatility in the European Union Emissions Trading Scheme (EU ETS) with respect to the presence of microstructure noise and jumps in the estimation procedure. In order to include jumps in the modeling of CO2 intraday volatility returns, we use the bipower variation measure as well as the more recent median realized volatility estimator. To deal with microstructure noise effects we apply Awartani et al’s (2009) ZT test to the price series of CO2 intraday futures for both bipower variation and median realized volatility and identify 20-minute returns as the optimal sampling frequency. Subsequently, the empirical analysis of both bipower variation and median realized volatility measures for CO2 prices reveals the presence of around 5% of “significant” jumps, especially during the “panic-to-cash” period of October 2008 in the EU ETS, and a lower range of estimates (around [0;0.15] for bipower variation and [0;0.10] for median realized volatility) compared with the “naive” estimator (around [0;0.23]).

What Trends in Energy Efficiencies? Evidence from a Robust Test

A proper modeling of the long-run behavior of energy and oil intensities is crucial in many respects. This paper aims at checking whether this long-run behavior should be modelled as a deterministic or a stochastic trend or both. We first apply a test for a deterministic trend robust to uncertainty about the stochastic trend. Our results indicate that, for the period 1960–2004, energy intensities of only 8 OECD countries out of 25 include a negative deterministic trend, 3 include a positive one and 14 seem to be better modelled by a stochastic trend only. When considering a sample of 73 non-OECD countries on the period 1971–2004, we show that only 22 exhibit a deterministic trend (negative for 15 countries and positive for 7 countries). A similar analysis for oil intensity leads to reject the hypothesis of an insignificant deterministic trend for 7 OECD countries out of 23 for the period 1965–2004 and 11 non-OECD countries out of 40 for the period 1971–2004. In the next step, we apply standard unit root tests and find that the unit root hypothesis is not very often rejected. We conclude that a main feature of energy intensities is the presence of a stochastic trend.

The role of trade openness and investment in examining the energy-growth-pollution nexus: Empirical evidence for China and India

ABSTRACT Most of the existing literature dealing with the relationship between carbon emissions, energy consumption and economic growth either suffers from ignoring relevant variables such as trade openness or investment, or suffers from using econometric methods that are unable to distinguish between short- and long-term causality and are not robust to the degree of integration of time series used for the analysis. This article suggests using the autoregressive distributed lag approach along with additional explanatory variables such as measures of trade and investment to shed a new light on the link between emissions, energy consumption and income in the two largest and energy-intensive developing economies: China and India. Our results, over the 1971–2009 period, provide evidence that investment plays a major role in shaping the relationship between carbon emissions, energy consumption and income in China while this is not the case in India. Furthermore, trade openness is found to play a key function in the short term in China but does not contribute to the emissions-energy-growth scenario in India.

Informed Trading in Oil-Futures Market

The weekly release of the U.S. inventory level by the DOE-EIA is known as the market mover in the U.S. oil futures market and to be a significant piece of information for all world oil markets in which the WTI is a price benchmark. We uncover suspicious trading patterns in the WTI futures markets in days when the inventory level is released that are higher than economists’ forecasts: there are significantly more orders initiated by buyers in the two hours preceding the official release of the inventory level. We also show a clear drop in the average price of -0.25% ahead of the news release. This is consistent with informed trading. We also provide evidence of an asymmetric response of the oil price to the news, and highlight an over-reaction that is partly compensated in the hours following the announcement.