Essays on monetary policy in open economies

This dissertation studies whether monetary policy has short run effects on output in emerging economies and characterizes the mechanisms of transmission of the monetary policy. Specifically it focuses on the real effects of the monetary policy in Brazil, where policymakers introduced structural reforms earlier than other emerging economies. Chapter I identifies the effects of monetary policy in Brazil using a vector autoregressive model. It finds that monetary policy has short run effects on output and nearly none on prices. This contrasts with the policy wisdom that monetary policy in EMEs can only affect prices. Chapter II, studies the interest rate channel of monetary policy in Brazil. It finds that surprise changes in the monetary policy interest rates have larger effects on the market interest rate during expansions than in recessions. This is attributed to the larger expected duration of expansion over recesions. Chapter III, uses a Dynamic Stochastic General Equilibrium model to study the effects of monetary policy when firms borrow to finance their working capital in an open economy. This issue is crucial in cases like Brazil where working capital credit explains half of the firms' borrowing and it quadrupled in the last 15 years. A monetary policy tightening has two effects: i) It discourages consumption (the traditional demand channel) and ii) It increases the production cost (known as the working capital channel). The final effect on inflation is unclear as these effects work in opposite directions. The model concludes that in an open economy where there is working capital borrowing, the aggregate demand channel dominates the working capital channel. This is due to the strong response of consumption to the exchange rate.Doctor of Philosoph

Axisymmetric smoothed particle hydrodynamics with self-gravity

The axisymmetric form of the hydrodynamic equations within the smoothed particle hydrodynamics (SPH) formalism is presented and checked using idealized scenarios taken from astrophysics (free fall collapse, implosion and further pulsation of a sun-like star), gas dynamics (wall heating problem, collision of two streams of gas) and inertial confinement fusion (ICF, -ablative implosion of a small capsule-). New material concerning the standard SPH formalism is given. That includes the numerical handling of those mass points which move close to the singularity axis, more accurate expressions for the artificial viscosity and the heat conduction term and an easy way to incorporate self-gravity in the simulations. The algorithm developed to compute gravity does not rely in any sort of grid, leading to a numerical scheme totally compatible with the lagrangian nature of the SPH equations.Comment: 17 pages, 10 figures, 1 Table. Accepted for publication in MNRA

Constraining deflagration models of Type Ia supernovae through intermediate-mass elements

The physical structure of a nuclear flame is a basic ingredient of the theory of Type Ia supernovae (SNIa). Assuming an exponential density reduction with several characteristic times we have followed the evolution of a planar nuclear flame in an expanding background from an initial density 6.6 10^7 g/cm3 down to 2 10^6 g/cm3. The total amount of synthesized intermediate-mass elements (IME), from silicon to calcium, was monitored during the calculation. We have made use of the computed mass fractions, X_IME, of these elements to give an estimation of the total amount of IME synthesized during the deflagration of a massive white dwarf. Using X_IME and adopting the usual hypothesis that turbulence decouples the effective burning velocity from the laminar flame speed, so that the relevant flame speed is actually the turbulent speed on the integral length-scale, we have built a simple geometrical approach to model the region where IME are thought to be produced. It turns out that a healthy production of IME involves the combination of not too short expansion times, t_c > 0.2 s, and high turbulent intensities. According to our results it could be difficult to produce much more than 0.2 solar masses of intermediate-mass elements within the deflagrative paradigma. The calculations also suggest that the mass of IME scales with the mass of Fe-peak elements, making it difficult to conciliate energetic explosions with low ejected nickel masses, as in the well observed SN1991bg or in SN1998de. Thus a large production of Si-peak elements, especially in combination with a low or a moderate production of iron, could be better addressed by either the delayed detonation route in standard Chandrasekhar-mass models or, perhaps, by the off-center helium detonation in the sub Chandrasekhar-mass scenario.Comment: 9 pages, 5 figures, 2 table

A century and three-quarters of Bank Rate and long-term interest rates in the United Kingdom

Over the years from 1844 to 2013, the United Kingdom had several distinct monetary policy regimes. This paper examines the relationship between the Bank of England policy rate and UK long-term rates in each regime. Our starting point is R. G. Hawtrey's A century of Bank Rate, which focused mainly on the classical Gold Standard. We also examine the Interwar years, post-Second World War years of policy by discretion and the recent regime of inflation targeting. We find that policy regimes that firmly anchor inflationary expectations result in long-run interest rates becoming less responsive to changes in monetary policy rates. This suggests a conflict between a regime that anchors inflationary expectations and one that allows a central bank to have significant effects on long-term rates via a short-term policy rate. © 2017 John Wiley & Sons Lt

3D Hydrodynamical Simulations of Nova Ejecta: Pollution of the Companion Star

Classical novae are cataclysmic binary star systems in which matter from an unevolved star is slowly accreted by a white dwarf companion. When enough mass has been accreted the pressure at the base of its envelope becomes high enough for the ignition of hydrogen, and a thermonuclear runaway occurs. Apart from releasing a large amount of energy in various parts of the electromagnetic spectrum, the nova explosion also results in the ejection of matter, forming an expanding shell around the system. In this study we aim to investigate the evolution of this nova shell to ascertain whether or not the secondary star can be significantly polluted by the ejecta material. To model the expanding shell we use a smooth particle hydrodynamics (SPH) code. The simulation is fully 3D and includes the nova ejecta, the main sequence companion, and the white dwarf (as a gravitational potential). The initial conditions for the nova ejecta are taken from the late stages of a detailed 1D hydrodynamical-nucleosynthetic simulation of the nova outburst on the white dwarf surface. Our very preliminary results show that some matter is accreted by the companion star, as expected, however it remains to be seen if the amount accreted is significant. We also find that the impact of the shell material on the main sequence star envelope enhances mass transfer in the system, so that some ejecta is probably also re-accreted by the white dwarf itself. This will affect the next nova explosion, as the white dwarf surface composition will be altered, especially at low metallicity. We also discuss necessary improvements for our future simulations

CCBuilder:An interactive web-based tool for building, designing and assessing coiled-coil protein assemblies

Motivation: The ability to accurately model protein structures at the atomistic level underpins efforts to understand protein folding, to engineer natural proteins predictably and to design proteins de novo . Homology-based methods are well established and produce impressive results. However, these are limited to structures presented by and resolved for natural proteins. Addressing this problem more widely and deriving truly ab initio models requires mathematical descriptions for protein folds; the means to decorate these with natural, engineered or de novo sequences; and methods to score the resulting models. Results: We present CCBuilder, a web-based application that tackles the problem for a defined but large class of protein structure, the α-helical coiled coils. CCBuilder generates coiled-coil backbones, builds side chains onto these frameworks and provides a range of metrics to measure the quality of the models. Its straightforward graphical user interface provides broad functionality that allows users to build and assess models, in which helix geometry, coiled-coil architecture and topology and protein sequence can be varied rapidly. We demonstrate the utility of CCBuilder by assembling models for 653 coiled-coil structures from the PDB, which cover >96% of the known coiled-coil types, and by generating models for rarer and de novo coiled-coil structures. Availability and implementation: CCBuilder is freely available, without registration, at http://coiledcoils.chm.bris.ac.uk/app/cc_builder

Spillover Events of Infection of Brown Hares (Lepus europaeus) with Rabbit Haemorrhagic Disease Type 2 Virus (RHDV2) Caused Sporadic Cases of an European Brown Hare Syndrome-Like Disease in Italy and Spain

Rabbit haemorrhagic disease virus (RHDV) is a lagovirus that can cause fatal hepatitis (rabbit haemorrhagic disease, RHD) with mortality of 80\u201390% in farmed and wild rabbits. Since 1986, RHDV has caused outbreaks in rabbits (Oryctolagus cuniculus) in Europe, but never in European brown hares (Lepus europaeus, EBH). In 2010, a new RHDV-related virus, called RHDV2, emerged in Europe, causing extended epidemics because it largely overcame the immunity to RHDV present in most rabbit populations. RHDV2 also was identified in Cape hare (Lepus capensis subsp. mediterraneus) and in Italian hare (Lepus corsicanus). Here, we describe two distinct incidents of RHDV2 infection in EBH that occurred in Italy (2012) and Spain (2014). The two RHDV2 strains caused macroscopic and microscopic lesions similar to European brown hare syndrome (EBHS) in hares, and they were genetically related to other RHDV2 strains in Europe. EBHs are common in Europe, often sharing habitat with rabbits. They likely have been exposed to high levels of RHDV2 during outbreaks in rabbits in recent years, yet only two incidents of RHDV2 in EBHs have been found in Italy and Spain, suggesting that EBHs are not a primary host. Instead, they may act as spillover hosts in situations when infection pressure is high and barriers between rabbits and hares are limited, resulting in occasional infections causing EBHS-like lesions. The serological survey of stocked hare sera taken from Italian and Spanish hare populations provided an understanding of naturally occurring RHDV2 infection in the field confirming its sporadic occurrence in EBH. Our findings increase the knowledge on distribution, host range and epidemiology of RHDV2

Climate Vulnerability and the Cost of Debt

We use indices from the Notre Dame Global Adaptation Initiative to investigate the impact of climate vulnerability on bond yields. Our methodology invokes panel ordinary least squares with robust standard errors and principal component analysis. The latter serves to address the multicollinearity between a set of vulnerability measures. We find that countries with higher exposure to climate vulnerability, such as the member countries of the V20 climate vulnerable forum, exhibit 1.174 percent higher cost of debt on average. This effect is significant after accounting for a set of macroeconomic controls. Specifically, we estimate the incremental debt cost due to higher climate vulnerability, for the V20 countries, to have exceeded USD 62 billion over the last ten years. In other words, for every ten dollars they pay in interest cost, they pay another dollar for being climate vulnerable. We also find that a measure of social readiness, which includes education and infrastructure, has a negative and significant effect on bond yields, implying that social and physical investments can mitigate climate risk related debt costs and help to stabilize the cost of debt for vulnerable countries