Disaggregated trade and disaggregated currency unions: a ranking of common currency effects

Andrew Rose has long argued that a common currency has a large effect on increasing trade. Recently, Rose has called into question the reliability of this conclusion, as new techniques have emerged for estimating gravity equations. This article uses the sector-specific gravity model developed by Anderson and Yotov (2010a) to investigate if disaggregated trade can provide a reliable estimate of a common currency’s effect. Disaggregating trade alone is insufficient to obtain a reliable estimate of a currency union, regardless of econometric technique, when the effect of a common currency on trade is uniform across all unions. Disaggregating the universe of currency unions with individual effects provides a reliable ranking of currency unions, independent of estimation method, by the effect that each union’s currency has on increasing trade. These rankings differ across sectors

Essays on currency unions and trade

The countries constituting a currency union (a group of countries sharing a common currency) are thought to be more integrated among themselves than are other countries. A common currency is thought to increase trade by eliminating costs associated with exchanging currencies and hedging against exchange rate risk. The existing literature has concluded that the increase in intra-union trade arising from the common currency ranges from 92% to 266% (Glick and Rose (2002)). My first chapter revisits these findings by regressing gravity equations using aggregate trade data and allowing for heterogeneous trade responses across currency unions. Only some currency unions are as integrated as was previously believed. Surprisingly, the currency union effects are positively correlated with tariffs on goods traded within the union: the higher the tariff, the greater the incentive for importers to avoid foreign exchange costs by purchasing within the union. Therefore, the common currency does not lower trade costs directly but becomes the means by which importers reduce total trade costs in the presence of high tariffs. To understand better the results described above, the second chapter uses the disaggregated gravity equation of Anderson and Yotov (2010) to show that the common currency reduces trade costs differently for different goods. A common currency has a larger effect on trade in certain types of manufactured goods than on trade in agricultural goods. Trade within the Eurozone and US Dollar zone consists of agricultural goods while trade within the currency unions in Africa and the Caribbean consists of manufactured goods. The third chapter proposes an alternative metric to evaluate the extent of integration within a currency union. This chapter examines whether or not the theory of Purchasing Power Parity (PPP) linking price levels and long-run exchange rates holds within currency unions. Using the cointegration methods of Johansen (1995), I find that PPP holds for a few unions and is sensitive to the time period examined and the currency union’s composition. Even in unions where PPP holds, PPP fails to hold for several country pairs within the union, undermining the ability of the union to survive in the long run

Improving the Robustness of Monocular Vision-Aided Navigation for Multirotors through Integrated Estimation and Guidance

Multirotors could be used to autonomously perform tasks in search-and-rescue, reconnaissance, or infrastructure-monitoring applications. In these environments, the vehicle may have limited or degraded GPS access. Researchers have investigated methods for simultaneous localization and mapping (SLAM) using on-board vision sensors, allowing vehicles to navigate in GPS-denied environments. In particular, SLAM solutions based on a monocular camera offer low-cost, low-weight, and accurate navigation indoors and outdoors without explicit range limitations. However, a monocular camera is a bearing-only sensor. Additional sensors are required to achieve metric pose estimation, and the structure of a scene can only be recovered through camera motion. Because of these challenges, the performance of monocular-based navigation solutions is typically very sensitive to the environment and the vehicle’s trajectory. This work proposes an integrated estimation and guidance approach for improving the robustness of monocular SLAM to environmental uncertainty. It is specifically intended for a multirotor carrying a monocular camera, downward-facing rangefinder, and inertial measurement unit (IMU). A guidance maneuver is proposed that takes advantage of the metric rangefinder measurements. When the environmental uncertainty is high, the vehicle simply moves up and down, initializing features with a confident and accurate baseline. In order to demonstrate this technique, a vision-aided navigation solution is implemented which includes a unique approach to feature covariance initialization that is based on consider least squares. Features are only initialized if there is enough information to accurately triangulate their position, providing an indirect metric of environmental uncertainty that could be used to signal the guidance maneuver. The navigation filter is validated using hardware and simulated data. Finally, simulations show that the proposed initialization maneuver is a simple, practical, and effective way to improve the robustness of monocular-vision-aided-navigation and could increase the amount of autonomy that GPS-denied multirotors are capable of achieving

Flight Investigation of the Effectiveness of an Automatic Aileron Trim Control Device for Personal Airplanes

A flight investigation to determine the effectiveness of an automatic aileron trim control device installed in a personal airplane to augment the apparent spiral stability has been conducted. The device utilizes a rate-gyro sensing element in order to switch an on-off type of control that operates the ailerons at a fixed rate through control centering springs. An analytical study using phase-plane and analog-computer methods has been carried out to determine a desirable method of operation for the automatic trim control

Senator James O. Eastland, Senator John Stennis, Representative William M. Colmer, Representative Jamie L. Whitten, Representative Thomas G. Abernethy, Representative G.V. \u27Sonny\u27 Montgomery, & Representative Charles H. Griffin to President Richard M. Nixon, 24 July 1969

Copy typed letter dated 24 July 1969 from Eastland, William M. Colmer, John Stennis, Jamie L. Whitten, Thomas G. Abernethy, G.V. \u27Sonny\u27 Montgomery, & Charles H. Griffin to Nixon, re: Mississippi delegation requesting appointment with president to discuss integration of Mississippi public schools.https://egrove.olemiss.edu/joecorr_f/1067/thumbnail.jp

Recency-sensitive retrieval processes in long-term free recall

In several experiments, each presentation of a to-be-remembered item in a free-recall list was both preceded and followed by a distracting activity and recall was delayed by an additional period of distracting activity. Pronounced long-term effects of recency were obtained, the standard short-term memory interpretation of recency effects in free recall notwithstanding. The results are interpreted as reflecting retrieval processes that are obscured by procedural characteristics of typical free-recall experiments.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22374/1/0000823.pd