Hard assets: The returns on rare diamonds and gems

This note examines the investment performance of diamonds and other gems (sapphires, rubies, and emeralds) over the period 1999–2010, using a novel data set of auction transactions. Over our time frame, the annualized real USD returns for white and colored diamonds equaled 6.4% and 2.9%, respectively. Since 2003, the average returns have been 10.0%, 5.5%, and 6.8% for white diamonds, colored diamonds, and other gems, respectively. Both white and colored diamonds outperformed stocks between 1999 and 2010. Nevertheless, gem returns covary positively with stock returns, underlining the importance of wealth-induced demand for luxury consumption in collectibles markets.     

AGRICULTURAL PRICE INSTABILITY: A SURVEY OF COMPETING EXPLANATIONS AND REMEDIES

Abstract There are two explanations for agricultural price dynamics. One follows cobweb logic and models fluctuations driven by expectation errors but emphasises that these expectations create complex dynamics and possibly chaos. The other stems from the rational expectations tradition of dynamics driven by real shocks. The empirical evidence tends to support the latter, but is not conclusive. The rational expectations model generates an optimal dynamic path from which no improvement can be expected from public intervention. However, if we take account of all the potential market failures in agricultural markets, and especially in developing countries, this conclusion might require some qualifications, although an appropriate policy design for stability has still to be achieved. This paper surveys the positive and normative literature on agricultural prices, highlighting empirical evidence and identifying remaining unresolved issues.     

Poverty and inequality under income and price dispersions

Abstract.  We introduce an analytical framework for welfare analysis that accounts for changes in the joint distribution of prices and incomes by using parametric formulae of poverty and inequality measures. We propose statistical indicators for the levels, variabilities and a statistical link of price indices and nominal living standards, which are consistent with a bivariate lognormal model. Our analysis provides intuitive insight about the social welfare impact of economic shocks affecting levels, variabilities, and correlation of prices and incomes. The roles of price and income variabilities for poverty and inequality are exhibited, with the possibility of several variation regimes. JEL classification: I32, O15, D31     

Informed trading before analyst downgrades: Evidence from short sellers

This paper studies short-selling prior to the release of analyst downgrades in a sample of 670 downgrades of Nasdaq stocks between 2000 and 2001. We find abnormal levels of short-selling in the three days before downgrades are publicly announced. Further, we show that this pre-announcement abnormal short-selling is significantly related to the subsequent share price reaction to the downgrade, and especially so for downgrades that prompt the most substantial price declines. Our findings are robust to various controls that might also affect short-selling such as pre-announcement momentum, three-day pre-announcement returns, and announcement-day share price. In addition, the results are independent of scheduled earnings announcements, analyst herding, and non-routine events near downgrades. Further evidence suggests that tipping is more consistent with the data than the prediction explanation which posits that short sellers successfully predict downgrades on the basis of public information about firms’ financial health. Finally, we present evidence that downgraded stocks with high abnormal short-selling perform poorly over the subsequent six months by comparison with those with low abnormal short-selling. Overall, our results support the hypothesis that short sellers are informed traders and exploit profitable opportunities provided by downgrade announcements.     

PURCHASING POWER PARITY FOR DEVELOPING AND DEVELOPED COUNTRIES. WHAT CAN WE LEARN FROM NON‐STATIONARY PANEL DATA MODELS?

Abstract.  The aim of this paper is to apply recently developed panel cointegration techniques proposed by Pedroni ( Oxford Bulletin of Economics and Statistics 61 (1999): Supplement, 653–670; Econometric Theory 20 (2004): 597–625) and generalized by Banerjee and Carrion-i-Silvestre (Working Paper 591, European Central Bank, February 2006) to examine the robustness of the PPP concept for a sample of 80 developed and developing countries. We find that strong PPP is verified for OECD countries and weak PPP for Middle East and North African countries. However, in African, Asian, Latin American and Central and Eastern European countries, PPP does not seem relevant to characterize the long-run behavior of the real exchange rate. Further investigations indicate that the nature of the exchange rate regime does not condition the validity of PPP, which is more easily accepted in countries with high rather than low inflation.     

Option pricing for GARCH-type models with generalized hyperbolic innovations

In this paper, we provide a new dynamic asset pricing model for plain vanilla options and we discuss its ability to produce minimum mispricing errors on equity option books. Given the historical measure, the dynamics of assets being modeled by Garch-type models with generalized hyperbolic innovations and the pricing kernel is an exponential affine function of the state variables, we show that the risk-neutral distribution is unique and again implies a generalized hyperbolic dynamics with changed parameters. We provide an empirical test for our pricing methodology on two data sets of options, respectively written on the French CAC 40 and the American SP 500. Then, using our theoretical result associated with Monte Carlo simulations, we compare this approach with natural competitors in order to test its efficiency. More generally, our empirical investigations analyse the ability of specific parametric innovations to reproduce market prices in the context of an exponential affine specification of the stochastic discount factor.     

An efficient heuristic for medium-term planning in shampoo production

This paper presents a single machine problem which occurs in shampoo production at medium-term planning phase. The considered production plant is linked to subsidiary companies which are themselves linked to final customers. The aim is to answer subsidiary companies requests by keeping their stocks in a window defined by their safety stock and maximum inventory levels. After an introduction, we present a formal definition of the problem. Next, we present a two-phase heuristic algorithm: the first phase is based on a greedy algorithm and the second phase on the Goldberg and Tarjan algorithm for the minimum cost flow problem. Experimental testings close to industrial instances show that the heuristic performs very efficiently.     

Learning by Failing: A Simple VaR Buffer

We study in this article the problem of model risk in VaR computations and document a procedure for correcting the bias due to specification and estimation errors. This practical method consists of “learning from model mistakes”, since it dynamically relies on an adjustment of the VaR estimates – based on a back‐testing framework – such as the frequency of past VaR exceptions always matches the expected probability. We finally show that integrating the model risk into the VaR computations implies a substantial minimum correction to the order of 10–40% of VaR levels.     

The Fear Premium and Daily Comovements of the S&P 500 E/P ratio and Treasury Yields before and during the 2008 Financial Crisis

I develop a new risk measure called the Total Fear Premium that generalizes Faugere‐Van Erlach (2009) and accounts for both flight‐to‐safety and flight‐to‐liquidity behavior. This new measure helps to explain why the daily S&P 500 forward earnings yield (E/P ratio) is strongly negatively correlated with daily Treasury yields of all maturities during the 2008 financial crisis, which is a reversal from the relation that prevailed before the crisis. The Total Fear Premium “mimics” the VIX during the financial crisis. Once the basic GARCH formulation modeling the interaction between the earnings yield and Treasury yields is augmented with the Total Fear Premium, the relation between the earnings yield and short‐term Treasury yields becomes significantly positive, in line with Fama's (1975) view that short‐term yields are good proxies for expected inflation. Two by‐products of this analysis are: 1) a new risk premium measure associated with flight‐to‐liquidity and 2) a new way to measure the inflation risk premium on a daily basis.     

Derivatives Clearing,Default Risk,and Insurance

Using daily data on margins and variation margins for all clearing members of the Chicago Mercantile Exchange, we analyze the clearing house exposure to the risk of default by clearing members. We find that the major source of default risk for a clearing member is proprietary trading rather than trading by customers. Additionally, we show that extreme losses suffered by important clearing firms tend to cluster, which raises systemic risk concerns. Finally, we discuss how private insurance could be used to cover the loss from defaults by clearing members.