Browsing by Subject "Gravity"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Center of Gravity Testing and Results
    (2014-07-24) Taylor, Brian
  • Thumbnail Image
    Item
    Essays on Economic Sanctions
    (2018-07) Walsh, William
    Do economic sanctions impact the economy on a macro level? I address this question using Iran as a case study. Over the last 20 years, the share of Iran's total trade with western developed economies has declined. Like most other countries, Iran's trade share with emerging markets, like China and India, has risen rapidly. Unlike most other countries however, Iran has been subject to an escalating series of sanctions by the United States, United Nations, and European Union. The threat of sanctions and, in some cases, outright restrictions on trade could also explain the shift in trade behavior. This paper attempts to disentangle these two effects. I employ a methodology developed by Novy (2013), which can be used to infer a measure of bilateral trade costs from macro data on bilateral trade flows, while controlling for changes in production. In general, I find that trade costs between Iran and the Emerging Markets have fallen dramatically, indicating that output growth alone cannot explain this shift in trade. I also use a three country dynamic trade model to determine whether a disruption in trade akin to the EU oil embargo imposed on Iran in 2012 can account for the recession Iran experienced that same year. The model can accommodate heterogeneity across countries with respect to population, output, and trade flows. The environment is a three country version of Backus, Kydland, and Kehoe (B.K.K.) (1994), and I model the trade disruption by increasing bilateral trade costs. In this setting, changes in trade costs affect, not only the dynamics of capital formation, but also the steady state level of capital, and hence the long run level of per capita output. In addition, I account for the possibility of sanction evasion via transshipment by embedding a shortest path problem into the model. Goods can take multiple routes from origin to destination and, in equilibrium, flow along the lowest cost path. The model is calibrated to bilateral trade and output data, and used to evaluate the impact of the oil and gas embargo imposed by the E.U. on Iran in 2012. In addition, I use discrepancies in bilateral trade mirror statistics to test for sanction evasion via transshipment. I find that the E.U. oil and gas embargo can account for about five sixths of the 6.6 % contraction in output, none of the fall in aggregate consumption expenditures, and one fifth of the 17 % fall in gross capital formation.
  • Thumbnail Image
    Item
    Five-dimensional Gravity and the Weak Gravity Conjecture
    (2019-05) Antoniou, Georgios
    The beginning of this thesis provides a brief guide to the notation we are going to use. After that, we present the Randall-Sundrum model and we outline the way it solves the hierarchy problem. To analyze the solutions the Lagrangian is perturbed up to second order. We then examine the possibility for a massive graviton, in the context of the Randall-Sundrum models. In particular, we examine the existence of the scalar modes of the metric decomposition. We present the de-Sitter, brane-world solutions corresponding to a dS five-dimensional space. Moreover, we discuss the swampland and focus on the Weak Gravity conjecture as well as on the AdS instability conjecture which follows from the former. We give the motivation and arguments supporting the Weak Gravity conjecture, derived from black hole physics. Then, we review the application of the AdS instability conjecture on Standard Model compactifications, and we retrieve recent results that support Dirac neutrinos and the normal hierarchy of the neutrino masses. We proceed by applying the same conjecture to the five-dimensional brane-world models. For the purposes of the present thesis, we limit the analysis to relatively simple cases, involving only a small number of particles in the five-dimensional bulk. We examine the constraints set on the masses of the fermionic/bosonic degrees of freedom, as well as on the five-dimensional cosmological constant, in order to avoid AdS minima. Finally, we discuss the Scalar Weak Gravity Conjecture and a recent modification of it.
  • Thumbnail Image
    Item
    Trade flow of U.S. recalled consumer products: a gravity model analysis
    (2014-09) Lindgren, Brian James Swanson
    This paper examines the hypothesis that the trade flow of recalled products and harm caused by recalled products will conform to economic theory in a similar way as the flow of goods in general. A Bergstrand-based gravity model is used in the analysis. My application uses a novel data set that includes measures of U.S. consumer product recalls from 2006 and 2007. The results of the analysis show that the flow of recalled goods corresponds to theory. The type of consumer products imported into the U.S., as well as those later recalled, are found to tend to be labor intensive. Better exporting country institutions corresponded to a relatively greater amount of goods later recalled.