Volatility spill-overs in commodity spot prices: New empirical results

The classical rational expectations model of commodity markets implies that expected spot price risk is an explanatory variable in spot price regressions; and also that inventory carryover, which is reduced by a larger price variance, creates autoregressive conditional heteroscedastic processes in spot prices. In order to falsify/verify this theory, it has typically been assumed that the square root of the conditional variance of spot prices, a proxy for spot price risk, enters the conditional mean function of spot prices. Based on this simple representation, a typical but counter intuitive outcome has been that spot price risk has an insignificant impact on spot prices, see, e.g., Beck (Beck, S., 1993. A Rational Expectations Model of Time Varying Risk Premia in Commodities Futures Markets: Theory and Evidence. International Economic Review 34, 149–168, Beck, S., 2001. Autoregressive Conditional Heteroskedasticity in Commodity Spot Prices. Journal of Applied Econometrics 16, 115–132). In this paper, we propose an alternative functional relationship (from GARCH(1,1) to GARCH(1,1)-AR(m)) between spot price risk and spot prices that is fully supported by the classical rational expectations model, and based on this new representation we are able to provide stronger empirical support for Muth's rational expectation theory.     

PRIOR ELICITATION IN MULTIPLE CHANGE‐POINT MODELS*

This article discusses Bayesian inference in change‐point models. The main existing approaches treat all change‐points equally, a priori, using either a Uniform prior or an informative hierarchical prior. Both approaches assume a known number of change‐points. Some undesirable properties of these approaches are discussed. We develop a new Uniform prior that allows some of the change‐points to occur out of sample. This prior has desirable properties, can be interpreted as “noninformative,” and treats the number of change‐points as unknown. Artificial and real data exercises show how these different priors can have a substantial impact on estimation and prediction.     

Brotherhood of competition: Foreign Direct Investment and domestic mergers

We examine the effects of mergers on Foreign Direct Investment (FDI), and on shaping national policies regarding FDI. In this work we develop a partial equilibrium model of an oligopolistic industry in which a number of domestic and foreign firms compete in the market for a homogeneous good in a host country. It is assumed that the number of foreign firms is endogenous and can be affected by the government policy in the host country. The government sets the policy (subsidies) to maximise social welfare. We allow domestic mergers. Our main results suggest that when the host country government imposes discriminatory lump-sum subsidy in favor of foreign firms, a merger of domestic firms will increase the number of FDI if the subsidy level is exogenous. With an endogenous level of subsidy, a merger of domestic firms will decrease (increase) the welfare if the domestic firms are more (less) efficient.     

Poverty in US Lesbian and Gay Couple Households

Poverty is a widely researched topic in economics. However, despite growing research on the economic lives of lesbians and gay men in the United States since the mid 1990s, very little is known about poverty in same-sex couple households. This study uses American Community Survey data from 2010 to 2014 to calculate poverty rates for households headed by different-sex versus same-sex couples. Comparing households with similar characteristics, the results show that those headed by same-sex couples are more likely to be in poverty than those headed by different-sex married couples. Despite that overall disadvantage, a decomposition of the poverty risk shows that same-sex couples are protected from poverty by their higher levels of education and labor force participation, and their lower probability of having a child in the home. Lastly, the role of gender – above and beyond sexual orientation – is clear in the greater vulnerability to poverty for lesbian couples.     

Healthcare costs of stroke and major bleeding in patients with atrial fibrillation treated with non-vitamin K antagonist oral anticoagulants

Objective: To assess long-term healthcare costs related to ischemic stroke and systemic embolism (stroke/SE) and major bleeding (MB) events in patients with non-valvular atrial fibrillation (NVAF) treated with non-vitamin K antagonist oral anticoagulants (NOACs).

Materials and methods: Optum’s Clinformatics Data Mart database from 1/2009–12/2016 was analyzed. Adult patients with ≥1 stroke/SE hospitalization (index date) were matched 1:1 to patients without stroke/SE (random index date), based on propensity scores. Patients with an MB event were matched to patients without MB. All patients had an NOAC dispensing overlapping index date, ≥12?months of eligibility pre-index date, and ≥1 NVAF diagnosis. The observation period spanned from the index date until the earliest date of death, switch to warfarin, end of insurance coverage, or end of data availability. Mean costs were evaluated: (1) per-patient-per-year (PPPY) and (2) at 1, 2, 3, and 4?years using Lin's method.

Results: The cost differences were, respectively, $48,807 and $28,298 PPPY for NOAC users with stroke/SE (n?=?1,340) and those with MB (n?=?3,774) events compared to controls. Cost differences of patients with vs without stroke/SE were $49,876, $51,627, $57,822, and $60,691 at 1, 2, 3, and 4?years post-index, respectively (p?p?Limitations: Limitations include unobserved confounders, coding and/or billing inaccuracies, limited sample sizes over longer follow-up, and the under-reporting of mortality for deaths occurring after 2011.

Conclusions: The incremental healthcare costs incurred by patients with vs without stroke/SE was nearly twice as high as those of patients with vs without MB. Moreover, each additional year up to 4?years after the first event was associated with an incremental cost for patients with a stroke/SE or MB event compared to those without an event.     

Russian agriculture during Putin’s fourth term: a SWOT analysis

Russian agriculture is coming off a successful period under Minister Alexander Tkachev. Despite his successes, new agricultural leaders were named in May 2018 to guide agriculture during Putin’s fourth term. The article analyses the condition of and prospects for the agricultural sector during 2018–2024, using a SWOT framework (strengths, weaknesses, opportunities and threats). The analysis examines four strengths, six weaknesses, four opportunities and three threats.     

Information in stock prices: the case of the 2016 U.S. presidential election

On the day before the 2016 U.S. presidential election, the odds of Hillary Clinton winning the presidency, according to political prediction markets, were above 90%. Surprisingly, Donald Trump won the Electoral College handily. In this study, we examine how movements in specific stock prices foreshadowed the eventual outcome. Specifically, we conduct a series of standard event-study tests focused on pharmaceutical companies, which became a focal point during the presidential campaign. Results show that while stocks of pharmaceutical companies significantly underperformed the market prior to the election, prices substantially increased beginning three days before the election outcome. This increase is both statistically significant and economically meaningful and robust to various event-study methodologies. These results suggest that some sectors of the stock market seemed to anticipate the election outcome.     

The architecture of R&D joint projects: the social network analysis approach

This paper examines the effect of network properties on the performance R&D joint projects. In particular, we examine the impact of network cohesion, diversity and shape on the performance of these of exploration and exploitation R&D projects. We test these measures using data on projects from European R&D networks developed under the framework of Eureka projects. The empirical results indicated some network properties enhance the project’s performance and these differ depending on the kind of technological project developed. Our results suggest a lower heterogeneity, greater cohesion and network centralisation in exploitation than in exploration projects. Our findings show different types of structures depending on the aim of the joint project and that there exist different degrees of cohesion between the partners that comprise the core and the peripheral nodes.     

Opportunistic shirking behaviour during unpaid overtime

We identify the presence of shirking by Major League Baseball umpires during indefinite unpaid overtime, as defined by extra innings. In the presence of new information about expected game length, umpires exert biases in ball and strike calls consistent with opportunistically reducing the likelihood of working additional time. General implications with respect to the effectiveness of salaried workers during unpaid overtime hours are discussed.