金融投机、实需与国际大宗商品价格——信息摩擦视角下的大宗商品价格影响机制研究

本文实证考察了2005-2015年金融投机和实需对国际大宗商品现货价格的影响及其作用机理。首先对具有信息噪音属性的金融投机进行了明确识别。其次,从多个维度出发区分市场信息摩擦状态,定量分析不同信息摩擦环境中金融投机和实需的影响差异。研究发现:大宗商品价格在长期中由实需因素主导,短期中由金融投机主导;短期中,相对于低信息摩擦环境,在市场波动性较高、金融压力上升以及投资者情绪高涨的高信息摩擦环境中,以金融投机为主的信息噪音对大宗商品价格的影响更强。进一步分析证实,相比于低信息摩擦环境,高信息摩擦环境中金融交易者的市场份额反而降低。据此,本文提出稳定大宗商品市场的关键在于提高市场透明度,减少信息摩擦,从市场质量出发降低信息噪音的影响。     

Bubbles in food commodity markets: Four decades of evidence

We use daily prices from individual futures contracts to test whether speculative bubbles exist in 12 agricultural markets and to identify whether patterns of bubble behavior exist over time. The samples begin as far back as 1970 and run through 2011. The findings demonstrate that all 12 agricultural markets experienced multiple periods of price explosiveness. However, bubble episodes represent a very small portion—between 1.5 and 2%—of price behavior during the 42-year period. In addition, most bubbles are short-lived with 80–90% lasting fewer than 10 days. Though receiving far less attention, negative bubbles contribute significantly to price behavior, accounting for more than one-third of explosive episodes. Markets over-react during both positive and negative explosive episodes, leading to a correction as they return to a random walk. This adjustment back to fundamental values is most pronounced with positive bubbles particularly in the earlier part of the sample. While the magnitudes of the corrections are generally small, there were a few instances of significant increases in prices and large over-reactions, most notably in the softs (e.g., cocoa 1973, coffee 1994, cotton 2010). We also find that explosive periods did not become more common or last longer in the second half of the sample period and that the most recent bubble episodes may not have been as severe as in mid-1970s.     

Financialization and speculators risk premia in commodity futures markets

J.M. Keynes coined the term normal backwardation, a situation where a futures price for a particular expiry month is less than the expected spot price for that month. He argued hedgers pay speculators a risk premium, giving rise to normal backwardation. We study the behavior of commodity futures before and since financialization of the markets, which started about 20 years ago. We find the poor returns to managed futures in recent years are likely due to the impact of financialization and the associated outside money suppressing the futures risk premium.     

Long-run equilibrium, short-term adjustment, and spillover effects across Chinese segmented stock markets and the Hong Kong stock market

This paper adopts a novel FIVECM-BEKK GARCH approach to examine the bilateral relationships among the A-share and B-share stock markets in China and the Hong Kong stock market. The evidence shows that these stock markets are fractionally cointegrated. Analyses of the spillover effects across these markets indicate that the A-share markets are most influential. The relaxation of government restrictions on the purchase of B shares by domestic residents accelerates the market integration process of A-share markets with the B-share and Hong Kong markets. The effects of the Asian crisis on the stock-return dynamic correlations vary across these markets.     

Time-varying impacts of demand and supply oil shocks on correlations between crude oil prices and stock markets indices

This paper investigates the time-varying impacts of demand and supply oil shocks on correlations between changes in crude oil prices and stock markets returns. The findings, obtained by means of a DCC-GARCH from June 2006 to June 2016, indicate that demand shocks positively affected the correlations between crude oil prices and stock market returns from late 2007 to mid-2008, during the apex of the financial markets volatility; from early 2009 to mid-2013, during global economy recovery from the financial crisis; and after 2015, when uncertainties about the Chinese growth and the US economy upturning arose. The dynamic conditional correlation, obtained after the removal of demand shocks effects, presented an average value of 0.13 when all economy sectors were considered and of 0.03 when the energy sector returns were excluded from the stock index. These correlations, still positive on average, suggest that exogenous supply oil shocks had little impact on US mainly enterprises cash flows over the last 10 years. Exceptions are the periods from 2006 to financial crisis and from 2014 until April 2016, when significant and unpredicted changes in oil market happened, considerably affecting the value of the main US companies.     

Systematic risk, and oil price and exchange rate sensitivities in Asia-Pacific stock markets

This paper examines the relationship between beta risk and realized stock index return in the presence of oil and exchange rate sensitivities for 15 countries in the Asia-Pacific region using the international factor model. Thirteen of the 15 countries have the expected beta signs and show significant sensitivity to domestic risk when the world stock market is in both up and down modes. In terms of oil sensitivity, only the Philippines and South Korea are oil-sensitive to changes in the oil price in the short run, when the price is expressed in local currency only. Basically no country shows sensitivity to oil price measured in US dollar regardless whether the oil market is up or down. Nine countries are affected by changes in the exchange rate. In terms of relative factor sensitivity distribution, one is willing to conclude that these stock markets are more conditionally sensitive to local currency oil price changes than to beta risk wherever the relationships are significant.     

Hedging, hedge accounting, and speculation in a rational expectations equilibrium

This paper explains corporate hedging and speculation in a two period rational expectations model. A risk averse manager represents a firm that is priced in a risk neutral market. The manager enters into a cash flow hedge of a forecast transaction by taking a short position in the futures market. When the futures position is chosen, the manager possesses private information regarding the firm’s production capacity. Mandatory disclosure of the futures position in the financial statements allows the market to draw inferences over the manager’s information. These inferences affect the market’s pricing decision and in turn the manager’s hedging decision. The futures position taken is chosen not only to reduce price risk exposure but to signal some capacity level. In equilibrium, however, the market anticipates the manager’s strategy and is not fooled.Considering varying managerial preferences, we analyze three settings. In the basic setting speculation occurs whenever the manager prefers high market values in both periods. In the second setting we add transaction costs and find that speculation is less likely. Finally, we introduce uncertainty regarding the manager’s preferences. If the market needs to determine prices based on expected preferences, incentives to speculate are mitigated in equilibrium but still present.     

Risk premia in crude oil futures prices

If commercial producers or financial investors use futures contracts to hedge against commodity price risk, the arbitrageurs who take the other side of the contracts may receive compensation for their assumption of nondiversifiable risk in the form of positive expected returns from their positions. We show that this interaction can produce an affine factor structure to commodity futures prices, and develop new algorithms for estimation of such models using unbalanced data sets in which the duration of observed contracts changes with each observation. We document significant changes in oil futures risk premia since 2005, with the compensation to the long position smaller on average in more recent data. This observation is consistent with the claim that index-fund investing has become more important relative to commerical hedging in determining the structure of crude oil futures risk premia over time.     

Price discovery and volatility spillovers in index futures markets: Some evidence from Mexico

This paper investigates the hypotheses that the recently established Mexican stock index futures market effectively serves the price discovery function, and that the introduction of futures trading has provoked volatility in the underlying spot market. We test both hypotheses simultaneously with daily data from Mexico in the context of a modified EGARCH model that also incorporates possible cointegration between the futures and spot markets. The evidence supports both hypotheses, suggesting that the futures market in Mexico is a useful price discovery vehicle, although futures trading has also been a source of instability for the spot market. Several managerial implications are derived and discussed.     

The effectiveness of incorporating higher moments in portfolio strategies: evidence from the Chinese commodity futures markets

This paper examines portfolio strategies that incorporate individual and systematic higher-order moments, within a stochastic optimization framework with uncertain mean and covariance. Using weekly, daily, and 30-minute interval data on Chinese commodity futures, we show that incorporating higher moments into portfolio strategies generally leads to better performance. The systematic fourth-order moment, among all systematic moments considered, can lead to the most robust, and a relatively large, improvement in investment performance, while the contribution of individual moments to the improved performance depends on the data horizon. We also find that adding higher moments brings superior performance in more cases for 30-minute-interval data than for other low-frequency data, suggesting that our strategy most likely performs best in 30-minute-rebalancing investments.     

Return and volatility co-movement in commodity futures markets: the effects of liquidity risk

Commodity markets are a widely researched topic in the field of finance. In this paper, we investigate the co-movement of return and volatility measures in different commodity futures markets and how these measures are affected by liquidity risk. First, we find that commodity returns display co-movement and that liquidity risk plays a key role in shaping asset return patterns. Moreover, we show that the volatilities of commodity returns co-move, and we demonstrate the role of liquidity risk in this joint pattern. We also find that the commodity markets we investigated share a common volatility factor that determines their joint volatility co-movement. Because liquidity risk affects both commodity returns and volatility shocks, it might be interpreted as the common causal factor driving both measures simultaneously. Therefore, we affirm the view that liquidity shocks are firmly related to two residual risks originating from both market return and market volatility. Finally, we also show that liquidity spillovers can significantly drive cross-sectional correlation dynamics.     

Cointegration test of oil price and us dollar exchange rates for some oil dependent economies

This study examines the long-run dynamics between oil price and the bilateral US dollar exchange rates for a group of oil-dependent economies before and after the 2008–2009 Global Financial Crises. Exchange rates are for the euro, Indian rupee, Russian ruble, South African rand, Ghanaian cedi and the Nigerian naira. The dependence on crude oil of these economies is either because fiscal revenues are primarily reliant on oil export receipts or because industrial production is heavily dependent on petroleum. Empirical results show evidence of a long run equilibrium relationship between oil price and exchange rate, especially for currencies of the key oil-exporting countries. This relationship is more evident in the post crisis period, which is also the period when both exchange rate volatility and the inverse relationship between oil price and exchange rate experienced a significant increase.     

Product markets and corporate investment: Theory and evidence

Investment patterns often associated with agency and information problems can emerge as rational responses to product-market rivalry. We illustrate this result when industry players make simultaneous or sequential investment decisions in the face of two negative externalities. One externality arises when all competing firms invest, thus eroding the gains to investment accruing to any one firm. Another externality arises when some firms do not invest and lose out to rivals who do invest. The value of investment therefore depends on the investment’s intrinsic merits and the actions of all competitors. Our analysis can rationalize investment patterns that might appear suboptimal when such externalities are ignored. For instance, our simultaneous model can justify investment levels that might otherwise be interpreted as under- or over-investment. Our sequential model shows that value-maximizing firms might optimally herd in their investment decisions. We present evidence supporting key aspects of both the simultaneous and sequential models.     

Finance and growth: Time series evidence on causality

This paper re-examines the empirical relationship between financial and economic development while (i) taking into account their dynamics and (ii) differentiating between stock market and banking sector development. We study the cointegration and causality between finance and growth for 22 advanced economies. Our time series analysis suggests that causality patterns depend on whether countries’ financial development stems from the stock market or the banking sector. We show that stock market development tends to cause economic development, while a reverse causality is mostly present between banking sector development and output growth. These findings indicate that the direction of causality between finance and growth is likely to be different at high levels of development.     

Price dynamics in refined petroleum spot and futures markets

This article characterizes the spot and futures price dynamics of two important physical commodities, gasoline and heating oil. Using a non-linear error correction model with time-varying volatility, we demonstrate many new results. Specifically, the convergence of spot and futures prices is asymmetric, non-linear, and volatility inducing. Moreover, spreads between spot and futures prices explain virtually all spot return volatility innovations for these two commodities, and spot returns are more volatile when spot prices exceed futures prices than when the reverse is true. Furthermore, there are volatility spillovers from futures to spot markets (but not the reverse), futures volatility shocks are more persistent than spot volatility shocks, and the convergence of spot and futures prices is asymmetric and non-linear. These results have important implications. In particular, since the theory of storage implies that spreasd vary with fundamental supply and demand factors, the strong relation between spreads and volatility suggests that these fundamentals — rather than trading induced noise — are the primary determinants of spot price volatility. The volatility spillovers, differences in volatility persistence, and lead-lag relations are consistent with the view that the futures market is the primary locus of informed trading in refined petroleum product markets. Finally, our finding that error correction processes may be non-linear, asymmetric, and volatility inducing suggests that traditional approaches to the study of time series dynamics of variables that follow a common stochastic trend that ignore these complexities may be mis-specified.     

The day-of-the-week effect in foreign exchange markets: multi-currency evidence

To investigate to what extent transaction mechanism matters, we examine the daily returns of 29 foreign exchange rates in the New York market. This paper finds that the day-of-the-week effect existed in the 1980s for some, not all, currencies. The fact that the day-of-the-week effect existed for only some currencies suggests that the US transaction mechanism alone cannot explain the anomaly. Furthermore, this paper finds that the day-of-the-week effect disappears for almost all currencies in the 1990s. This latter result is consistent with previous studies on anomalies in the stock markets.     

Regulatory reform and market efficiency: The case of Indian agricultural commodity futures markets

We present the results of two efficiency measures that include intraday return predictability measure based on order imbalance and measures of several variance ratio tests on intraday subsamples of nine major Indian agricultural commodity futures (castor seed, cotton oil cake, rape mustard seed, soybean, refined soya oil, crude palm oil, jeera, chana, and turmeric) quoted in the National Commodity and Derivatives Exchange (NCDEX). We perform the efficiency measures on five subsamples with holding periods of 5, 10, 15, 30, and 60 min over two sample periods following the announcement of the merger between the Forward Market Commission (FMC) and Securities Exchange Board of India (SEBI). We compare results of tests of weak-form market efficiency of futures markets between two periods (pre-merger period and post-merger period). Our results confirm that Indian agricultural commodity futures markets continue to remain inefficient in the short-term during both pre-merger and post-merger periods. Based on these findings, it is likely that profitable trading strategies in the short intraday intervals will be available for traders and market participants during post-merger period. Thus, regulators must focus more on policy initiative so as to enhance market quality in order to address such inefficiencies in Indian commodity futures markets.     

The organization of financial exchange markets: Theory and evidence

This article presents theory and evidence regarding the organization of financial exchange markets. It derives conditions under which (1) a member-owned exchange has a monopoly over the trade of a particular financial contract and its close substitutes, and (2) exchange members earn economic rents. Given these conditions, low cost suppliers of financial services form an exchange that is large enough to deter entry by competing exchanges but which is smaller than optimal. However, exchanges trading differentiated products may not merge to exploit all scope economies. Furthermore, exchanges that offer a variety of products may allow some members to trade only a subset of these products in order to preserve member rents. The evidence regarding exchange market shares, rents, and membership policies is broadly consistent with these predictions.     

Quantifying the speculative component in the real price of oil: The role of global oil inventories

One of the central questions of policy interest in recent years has been how many dollars of the inflation-adjusted price of oil must be attributed to speculative demand for oil stocks at each point in time. We develop statistical tools that allow us to address this question, and we use these tools to explore how the use of two alternative proxies for global crude oil inventories affects the empirical evidence for speculation. Notwithstanding some differences, overall these inventory proxies yield similar results. While there is evidence of speculative demand raising the price in mid-2008 by between 5 and 14 dollars, depending on the inventory specification, there is no evidence of speculative demand pressures between early 2003 and early 2008. As a result, current policy efforts aimed at tightening the regulation of oil derivatives markets cannot be expected to lower the real price of oil in the physical market. We also provide evidence that the Libyan crisis in 2011 shifted expectations in oil markets, resulting in a price increase of between 3 and 13 dollars, depending on the inventory specification. With regard to tensions with Iran in 2012, the implied price premium ranges from 0 to 9 dollars.