Uncertainty, Spillovers, and Forecasts of the Realized Variance of Gold Returns

Using data for the group of G7 countries and China for the sample period 1996Q1 to 2020Q4, we study the role of uncertainty and spillovers for the out-of-sample forecasting of the realized variance of gold returns and its upside (good) and downside (bad) counterparts. We go beyond earlier research in that we do not focus exclusively on U.S.-based measures of uncertainty, and in that we account for international spillovers of uncertainty. Our results, based on the Lasso estimator, show that, across the various model configurations that we study, uncertainty has a more systematic effect on out-of-sample forecast accuracy than spillovers. Our results have important implications for investors in terms of, for example, pricing of related derivative securities and the development of portfolio-allocation strategies.

Financial Engineering by City Governments: Factors Associated with the Use of Debt-Related Derivatives

Despite significant coverage in the financial press in recent years, financial engineering by city governments via the use of financial derivatives such as interest rate swaps remain an understudied area of urban financial policy. Indeed, press accounts and other case or conceptual urban studies research emphasizing the downside of these transactions are some of the only sources of information on these instruments. These stories and studies often allude to or speculate on a more basic question: Why would a government choose to enter into a complex financial instrument like a debt-related derivative? This research posits three exploratory hypotheses—financial health, financial experience and/or financial sector influence, and governance structure—culled from media accounts and the urban studies literature on the use of debt-related derivatives by city governments in the United States. It empirically explores these hypotheses by examining the various fiscal, financial, and issuer characteristics of the largest 50 U.S. cities and their choice of whether to use debt-related derivatives. The research finds that the characteristics of government most associated with debt-related derivative use are declining financial condition, increased financial experience and/or financial sector influence, and prior use of interest rate swaps.

Dynkin's Games and Israeli Options

We start by briefly surveying a research on optimal stopping games since their introduction by Dynkin more than 40 years ago. Recent renewed interest to Dynkin’s games is due, in particular, to the study of Israeli (game) options introduced in 2000. We discuss the work on these options and related derivative securities for the last decade. Among various results on game options we consider error estimates for their discrete approximations, swing game options, game options in markets with transaction costs, and other questions.

A Review on Carbon-rich Molecules in Space

We present and discuss carbon-rich compounds of astrochemical interest such as polyynes, acetylenic carbon chains and the related derivative known as monocyanopolyynes and dicyanopolyynes. Fullerenes are now known to be abundant in space, while fulleranes - the hydrogenated fullerenes - and other carbon-rich compounds such as very large polycyclic aromatic hydrocarbons (PAHs) and heavy petroleum fractions are suspected to be present in space. We review the synthesis, the infrared spectra as well as the electronic absorption spectra of these four classes of carbon-rich molecules. The existence or possible existence in space of the latter molecules is reported and discussed.

The Frontotemporal (Pterional) Approach

The frontotemporal, so-called pterional, approach has evolved with the contribution of many neurosurgeons over the past century. It has stood the test of time and has been the most commonly used transcranial approach in neurosurgery. In its current form, drilling the sphenoid wing as far down as the superior orbital fissure with or without the removal of the anterior clinoid, thinning the orbital roof, and opening the Sylvian fissure and basal cisterns are the hallmarks of this approach. Tumoral and vascular lesions involving the sellar/parasellar area, anterior and anterolateral circle of Willis, middle cerebral artery, anterior brainstem, upper basilar artery, insula, basal ganglia, mesial temporal region, anterior cranial fossa, orbit, and optic nerve are within the reach of the frontotemporal approach. In this article, we review the origins, evolution, and modifications of the frontotemporal approach and update the discussion of some of the related derivative procedures.