Browsing by Author "Ostdiek, Barbara"

Now showing 1 - 6 of 6
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    Covariance Estimation in Dynamic Portfolio Optimization: A Realized Single Factor Model*
    (SSRN, 2009) Kyj, Lada; Ostdiek, Barbara; Ensor, Katherine
    Realized covariance estimation for large dimension problems is little explored and poses challenges in terms of computational burden and estimation error. In a global minimum volatility setting, we investigate the performance of covariance conditioning techniques applied to the realized covariance matrices of the 30 DJIA stocks. We find that not only is matrix conditioning necessary to deliver the benefits of high frequency data, but a single factor model, with a smoothed covariance estimate, outperforms the fully estimated realized covariance in one-step ahead forecasts. Furthermore, a mixed-frequency single-factor model - with factor coefficients estimated using low-frequency data and variances estimated using high-frequency data performs better than the realized single-factor estimator. The mixed-frequency model is not only parsimonious but it also avoids estimation of high-frequency covariances, an attractive feature for less frequently traded assets. Volatility dimension curves reveal that it is difficult to distinguish among estimators at low portfolio dimensions, but for well-conditioned estimators the performance gain relative to the benchmark 1/N portfolio increases with N.
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    Dynamic jump intensities and news arrival in oil futures markets
    (Springer Nature, 2020) Ensor, Katherine B.; Han, Yu; Ostdiek, Barbara; Turnbull, Stuart M.; Center for Computational Finance and Economic Systems
    We introduce a new class of discrete-time models that explicitly recognize the impact of news arrival. The distribution of returns is governed by three factors: dynamics volatility and two Poisson compound processes, one for negative news and one for positive news. We show in a model-free environment that the arrival of negative and positive news has an asymmetric effect on oil futures returns and volatility. Using the first 12 futures contracts, our empirical results confirm that the effects of negative and positive news are described by different processes, a significant proportion of volatility is explained by news arrival and the impact of negative news is larger than that of positive news.
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    Impact of News on Crude Oil Futures
    (2017-04-21) Han, Yu; Ensor, Katherine; Ostdiek, Barbara; Turnbull, Stuart
    Crude oil futures are worlds the most actively traded commodity futures, with more than 3 billion barrels per year in open interest. In this thesis we use related news to model the price dynamics of oil futures. We examine the empirical patterns of oil market news data processed by Thompson Reuters News Analytics, plus the intraday trading data of the WTI futures price traded on NYMEX. Then we build a three factor stochastic model for futures prices on the whole curve, using interest rate, convenience yield and spot price. The Kalman filter was used to obtain quasi-maximum likelihood estimators. We found that news can significantly explain the price movements and volatility clustering, as well as its skewness and kurtosis. We also found that negative news has an higher explanatory power of price dynamics than positive news, indicating an asymmetrical behavior of information with different tones.
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    Income Variability: Effects on U.S. Income Inequality and Tax Progressivity
    (2012-09-05) Splinter, David; Zodrow, George R.; Diamond, John W.; Narajabad, Borghan N.; Ostdiek, Barbara
    Income variability explains a significant fraction of the increase in annual income inequality. Chapter 1 considers the impact of variability on tax unit inequality. Using income tax return panel data, I estimate that between a tenth and a quarter of the increase in top one percent income shares between the early 1980s and 2000s was caused by variability. Increased income variability over this period resulted from mean-reverting fluctuations in the bottom quintile and top one percent. Variability in the top of the distribution seems partly driven by permanent income shifting in response to the Tax Reform Act of 1986. Chapter 2 examines the individual earnings distribution. Using Social Security Administration earnings panel data, I estimate that variability explains half of the increase in annual inequality in the bottom half of the distribution between 1973 and 1985. When workers with years of zero earnings are included, increasing earnings variability explains almost all of this group's increase in inequality. The increase in earnings variability appears to be explained by an increased fraction of working age men with years of zero earnings. Annual individual earnings inequality in the bottom half of the distribution not only increased with variability in the 1970s and 1980s, but also fell with variability in the 1950s and early 1960s. This suggests that the U-shaped trend in income inequality observed over these four decades was partly caused by first a fall and then a rise in earnings variability. Between 1985 and 2000, falling variability caused most of the decline in annual earnings inequality within the bottom half of the distribution. Within the top of the distribution, earnings inequality increased over this period because of changes in permanent earnings and not increasing variability. Income variability means that in a progressive tax system annual and lifetime federal tax rates can diverge. Chapter 3 shows that on an annual basis, those at the bottom of the distribution pay little or no federal income taxes, while on a lifetime basis they pay average tax rates about five percentage points higher. Income variability also means there is a trade-off between vertical and horizontal equity.
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    Oil and Macroeconomy
    (2013-09-16) Rizvanoghlu, Islam; Temzelides, Ted; Hartley, Peter R.; Ostdiek, Barbara; Narajabad, Borghan N.; Medlock, Kenneth B., III
    Traditional literature on energy economics gives a central role to exogenous political events (supply shocks) or to global economic growth (aggregate demand shock) in modeling the oil market. However, more recent literature claims that the increased precautionary demand for oil triggered by increased uncertainty about a future oil supply shortfall is also driving the price of oil. Based on this motivation, in the first chapter, we propose to build a DSGE model to explore macroeconomic consequences of precautionary demand motives in the crude oil market. The intuition behind the precautionary demand is that since firms, using oil as an input in their production process, are concerned about the future oil prices, it is reasonable to think that in the case of uncertainty about future oil supply (such as a highly expected war in the Middle East), they will buy futures and/or forward contracts to guarantee a future price and quantity. We simulate the effects of demand shocks in the oil market on macroeconomic variables, such as GDP and inflation. We find that under baseline Taylor-type interest rate rule, real oil price, inflation and output loss overshoot and go down below steady state at the next period if uncertainties are not realized. However, if the shock is realized, i.e. followed by an actual supply shock, the effect on inflation and output loss is high and persistent. Second chapter analyzes the effect of storage market on the monetary policy formulation as a response to an oil price shock. Some recent literature suggests that although high oil prices contributed to recessions, they have never had a pivotal role in the creation of those economic downturns. A general consensus is that the decline in output and employment was due to the rise in interest rates, resulting from the Fed’s endogenous response to the higher inflation induced by oil price shocks. However, traditional literature assumes that oil price shocks are exogenous to the U.S economy and they ignore the storage market for the crude oil. In this regard, a model with an endogenous (demand shock) or exogenous (supply shock) price shock may produce a totally different monetary policy proposal when there exists a market for storage for the crude oil. The rationale behind this idea is that when goods’ prices are sticky in the economy, the monetary authority can effect the level of inventories through the changes in the real interest rates. Thus, lower interest rate rules, as proposed in the literature, will cause additional oil supply scarcity in the spot market. Therefore, an optimal monetary policy that maximizes the welfare in the economy should consider the adverse affect of low interest rates on the crude oil market.
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    The Impact of Energy Derivatives on the Crude Oil Market
    (2000) Fleming, Jeff; Ostdiek, Barbara; James A. Baker III Institute for Public Policy