Testing commodity futures market efficiency under time-varying risk premiums and heteroscedastic prices

We propose a novel test to measure market efficiency while estimating the time-varying risk premiums of commodity futures, given that the prices are heteroscedastic. The risk premium is estimated using a state-space model with a Kalman filter modified for heteroscedasticity. Using 79 commodity futures traded on 16 exchanges during the period 2000–2014 and a Monte Carlo simulation, we demonstrate that the proposal produces robust results compared with conventional approaches. The global financial crisis has improved the efficiency and affected the trading volumes of commodity futures, but it has had no effect on the average or the volatility of risk premiums.     

Impact of the 2014 Suspension Agreement on sugar between the United States and Mexico

In December 2014, the U.S. and Mexico agreed to a suspension agreement that set a $22.25/cwt import price floor on U.S. sugar imports from Mexico. A partial equilibrium trade model was developed to estimate the economic impact the agreement would have had if it had been in effect from 2008 to 2014. In years when the price floor would have been binding, on average, U.S. producers would have gained $138 million and Mexican producers would have lost $218 million. However, total Mexican welfare would have actually increased by $11.5 million. Furthermore, the average price floor that would have maximized total Mexican welfare over that period is $22.76/cwt. Also, under certain supply and demand elasticity conditions, the average price floor that would have maximized joint U.S. and Mexican producer welfare over that period is $21.91/cwt. The latter two estimates are both close to the actual price floor agreed to in the 2014 Suspension Agreement.     

Understanding heterogeneity in price changes and firm responses to a national unhealthy food tax in Mexico

To address the high prevalence of overweight and obesity in Mexico, an eight percent ad valorem excise tax on non-essential energy-dense foods came into effect on 1 January 2014. This paper estimates price changes after the tax implementation among the top four food categories and by leading vs. non-leading firms using purchase information from over 6000 urban households in the 2012–2015 Nielsen Mexico Consumer Panel. We create product-city-month specific prices that correct for potential biases associated with household and retailer characteristics. Using these corrected prices, we conduct before and after quasi-experimental analyses and find that price increases were larger than eight percent for cookies but were less than eight percent for ready-to-eat cereals, salty snacks, and pre-packaged sweet bread. For the latter food group, event-study analyses on the gradual price change over time suggest that price changes might be the result of an increasing price trend rather than the tax implementation. Firm-level analyses mostly show that price increases by the leading firms were larger than the overall increase at the food market level, helping explain variability in post-tax declines in food purchases as reported in other research. We also find that price changes are generally underestimated when we do not correct prices for biases associated with households and retailers. These results improve our understanding of the mechanisms behind heterogeneous changes in purchases after the tax implementation. Additionally, these results can assist policymakers when designing or improving taxes on non-essential energy-dense foods at a time when these policy options are high on the agenda in many places.     

The side effects of quantitative easing: Evidence from the UK bond market

We examine the returns to UK government bonds before, during and between the phases of quantitative easing to identify the side effects for the market itself. We show that the onset of QE led to a sustained reduction in the costs of trading and removed some return regularities. However, controlling for a wide range of market activity, including issuance and QE announcements, we find evidence that investors could have earned excess returns after costs by trading in response to the purchase auction calendar. Drawing on economic theory, we explore the implications of these findings for both the efficiency of the market and the costs of government debt management in both the short and long run.     

Short-term overreaction to specific events: Evidence from an emerging market

This paper investigates the short-term overreaction to specific events and whether stock prices are predictable in the Egyptian stock exchange (EGX). We find evidence of the short-term overreaction in the EGX. Losers (“bad news” portfolios) significantly outperform winners (“good news” portfolios) and investors can earn abnormal return by selling the winners and buying losers. Terrorist attacks have negative and significant abnormal returns for three days post event followed by price reversals on day four post event. Whereas, the tensions in the Middle East region have a negative and significant abnormal returns on event day followed by price reversals on day one post event. Moreover, the formation of a new government has no effect on the average abnormal returns post event in the EGX. The results also show that small firms tend to have greater price reversals compared to large firms. Overall, our results provide evidence of the leakage of information in the EGX.     

Ethical dilemmas: Teaching futures in schools

Educational policy is implicitly futures oriented, yet in most instances fails to engage learners with explicit futures tools and concepts at a school level. Futures studies in education, or futures education has the potential to reposition learning as purposeful and mobilizes the lives of participants by connecting the curriculum of schools with the multifaceted futures of learners. This is a complex task within the tensions often existing between: the cultural role of a school, the expectations of a society, the expertise of teachers, and the increasingly diverse needs of learners (Bateman, 2012). It is between the tensions of these things that the ‘ethical’ issues of what is taught, or omitted as content in a classroom and the consequences of these choices are evident.This paper highlights ethical and moral dilemmas, as they were apparent in two futures education projects. In the first study, the teachers discuss the inherent limitations of offering a broader and more futures oriented curriculum. In the second study, teachers reflect upon their students’ anxiety with regards to futures images as they are interrogated within a curriculum study. Each of these studies highlights the ethical challenges that arise, when possible, preferable and probable futures are developed as part of learning in school settings, which are culturally and demographically diverse.Tirri and Husu (2002) highlight the ethical dilemmas, which emerge in classrooms around the world, based on conflicts in values and competing intentions between key stakeholders. In the studies which contribute to this discussion, there is evidence to suggest that futures thinking causes conflict within an individual's perception of how the world should be, or their worldview as a result of futures imagining which goes beyond what is taken for granted, or is an assumed future eventuality. In the same way, Carrington, Deppeler, and Moss (2010) argue that all curriculum choices about what is taught (or not taught) in a classroom reflect an ethical decision made by a teacher, with regards to what is foregrounded for learning and what is omitted.It is crucial to re-examine the role of a school in educating students for their futures, as opposed to educating students with an aim of furthering governmental agendas. More significantly, however, as this paper highlights, it is exploring the boundaries of what is acceptable or unacceptable, appropriate or inappropriate to teach in a classroom, given the changing diversities of schools and education systems throughout the world.     

On pure-strategy Nash equilibria in price–quantity games

This paper examines the existence and characteristics of pure-strategy Nash equilibria in oligopoly models in which firms simultaneously set prices and quantities. Existence of a pure-strategy equilibrium is proved for a class of price–quantity games. If the demand function is continuous, then the equilibrium outcome is similar to that of a price-only model. With discontinuous demand and limited spillover, there are rationing equilibria in which combined production falls short of market demand. Moreover, there might again be an equilibrium reflecting the outcome of a price game. Competition in price and quantity thus yields Bertrand outcomes under a variety of market conditions.     

The effect of specific discount pattern in terms of price promotions on perceived price attractiveness and purchase intention: An experimental research

This study aims to investigate consumer perceptions and reactions in terms of specific discount patterns (fixed price, 40% discount, discount from 500 TL to 300 TL and 20% + 25% discount) in price promotion. According to the results, specific discount patterns in price promotion have a significant effect on perceived price attractiveness and purchase intention. When the specific discount patterns in price promotion and gender interaction were analyzed in terms of perceived price attractiveness, the scenario of the “discount from TL 500 to TL 300” significantly differentiated from both the control scenario (fixed price) and experimental scenarios for female. For males, no significant difference was found between the control and experimental scenarios. In terms of purchase intention, a significant difference was found between the fixed price scenario and the discount scenario from 500 TL to 300 TL and between the fixed price and 20% + 25% discount scenario. The theoretical managerial implications of the study were discussed, and future research suggestions were presented.     

S&P 500 Affiliation and Stock Price Informativeness

Abstract

When firms are added to a stock index, more information should be discovered, traded on, and incorporated into their stock prices, making them more informative. We test this hypothesis using a large sample of additions to the S&P 500 index. Using two alternative statistical tests, we find that the stocks added experience more random, less predictable return and, thus, appear to be priced more efficiently information-wise. We further find concurrent increases in institutional ownership and investor awareness, which tend to contribute to the higher pricing efficiency, adding to the literature. These findings should be of interest to academics and practitioners.     

Price gap anomaly in the US stock market: The whole story

This paper analyses the price gap anomaly in the US stock market (comprised of the DJI, S&P 500 and NASDAQ) covering the period 1928 to 2018. This paper aims to investigate whether or not price gaps create market inefficiencies. Price gaps occur when the current day’s opening price is different from the previous day’s closing price due orders placed before the opening of the market. Several hypotheses are tested using various statistical tests (Student’s t-test, ANOVA, Mann-Whitney test), regression analysis, and special methods, that is, the modified cumulative returns and the trading simulation approaches. We find strong evidence in favour of abnormal price movements after price gaps. We observe that during a gap day prices tend to change in the direction of the gap. A trading strategy based on this anomaly was efficient in that its results were not random, indicating that this market was not efficient. The momentum effect was found to be temporary and no evidence of seasonality in price gaps was found. Lastly, our results were also contrary to the myth that price gaps tend to get filled.