65 research outputs found
Effects of trade barriers on development and growth
A basic definition of trade barriers could be âall factors that influence the amount of goods and services shipped across international bordersâ (Feenstra and Taylor, 2017a). This definition is quite neutral, and it needs to be understood that the word âbarrierâ has a negative connotation, which means that a trade barrier would be any instrument that limits or restrict trade between countries, as opposed to free trade. It is generally accepted that free trade is good for productivity and economic growth, but it is also true that most countries apply some sort of trade restriction, for different reasons
New insights from a structural economic dynamic approach to balance of payments constrained growth
In this paper it is shown that once-for-all variations in the level of the exchange rate may play an important role in the sectoral composition of the economy and this fact has important implications in terms of a disaggregated version of the Thirlwallâs law even if the argument of the quantitative unimportance of relative price movements holds. The growth rate of a country is then shown to be affected by once-for-all movements in the level of nominal exchange rates and the concept of a natural exchange rate is introduced
New evidence on Allyn Young's style and influence as a teacher
This paper publishes the hitherto unpublished correspondence between Allyn Abbott Young's biographer Charles Blitch and 17 of Young's former students or associates. Together with related biographical and archival material, the paper shows the way in which this adds to our knowledge of Young's considerable influence as a teacher upon some of the twentieth century's greatest economists. The correspondents are as follows: James W Angell, Colin Clark, Arthur H Cole, Lauchlin Currie, Melvin G de Chazeau, Eleanor Lansing Dulles, Howard S Ellis, Frank W Fetter, Earl J Hamilton, Seymour S Harris, Richard S Howey, Nicholas Kaldor, Melvin M Knight, Bertil Ohlin, Geoffrey Shepherd, Overton H Taylor, and Gilbert Walker
Combined U-Pb and Lu-Hf isotope analyses by laser ablation MC-ICP-MS : methodology and applications
O sistema isotĂłpico LutĂ©cio-Hafnio representa uma das ferramentas mais recentes e poderosas para estudos isotĂłpicos e geocronolĂłgicos. AnĂĄlises combinadas in situ de U-Pb e Lu-Hf sobre zircĂŁo pelo LA-MC-ICP-MS permitem caracterizar isotopicamente o magma onde ele cristalizou, fornecendo valiosas informaçÔes para estudos de proveniĂȘncia de sedimento e de evolução crustal. Nesse trabalho descrevemos a sistemĂĄtica de Lu-Hf pelo LA-MC-ICP-MS implantada no laboratĂłrio de Geocronologia da Universidade de BrasĂlia e reportamos os resultados obtidos de repetidas anĂĄlises de trĂȘs padrĂ”es de zircĂŁo: GJ-1 = 0.282022 ± 11 (2SD, n=56), Temora 2 = 0.282693 ± 14 (2SD, n=25) and UQ-Z = 0.282127 ± 33 (2SD, n=11). Foi tambĂ©m caracterizada arazĂŁo isotĂłpica 176Hf/177Hf(0.282352 ± 22, 2SD, n=14) de um zircĂŁo usado como padrĂŁo interno do laboratĂłrio. Como aplicação geolĂłgica, analisamos dois zircĂ”es complexos selecionados a partir de uma amostra de migmatito da ProvĂncia de Borborema, NE do Brasil. Sobre a base dos dados U-Pb e Lu-Hf foram identificados em ambos os zircĂ”es dois eventos de cristalização. Um evento mais antigo de 2.05 Ga nos nĂșcleos herdados, representa um evento magmĂĄtico Paleoproterozoico bem conhecido na ProvĂncia Borborema. Um segundo evento de ~ 575 Ma, reconhecido nas bordas, representa um evento magmĂĄtico-metamĂłrfico NeoproterozĂłico (Brasiliano). ________________________________________________________________________________________ ABSTRACTThe Lutetium-Hafnium isotopic system represents one of the most innovative and powerful tools for geochronology and isotopic studies. Combined U-Pb and Lu-Hf in situ analyses on zircon by LA-MC-ICP-MS permit to characterize isotopically the host magma from which it crystallized furnishing significant information for sediment provenance and crustal evolution studies. In this paper e describe the Lu-Hf systematic by LA-MC-ICP-MS developed in the laboratory of Geochronology of the University of Brasilia and report the results obtained by repeated analyses of 176Hf/177Hf isotopic ratio of three zircon standards: GJ-1 = 0.282022 ± 11 (n=56), Temora 2 = 0.282693 ± 14 (n=25) and UQZ = 0.282127 ± 33 (n=11). The 176Hf/177Hf ratio (0.282352 ± 22, n=14) of gem quality zircon used as in-house standard have been also characterized. As a geological application, we analyzed two complex zircons selected from a migmatitic rocks from the Borborema Province, NE Brazil. On the basis of U-Pb and Lu-Hf data, two main crystallization events have been identified in both studied zircons. An older event at ca. 2.05 Ga recognized in the inherited cores represents a well-characterized paleoproterozoic magmatic event that affected the whole Borborema Province. A second crystallization event at ~ 575 Ma, recognized at the rims, represents a Neoproterozoic (Brazilian) high grade metamorphic-magmatic event
- âŠ