167 research outputs found

    Testing Mundell’s Intuition of Endogenous OCA Theory

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    This paper presents an empirical assessment of the endogenous optimum currency area theory. Frankel and Rose (1998) study the endogeneity of a currency union through the lens of international trade flows. Our study extends Frankel and Rose's model by using FDI flows to test the original theory developed by Mundell in 1973. A gravity model is used to empirically assess the effectiveness of the convergence criteria by examining location specific advantages that guide multinational investment within the European Union. A fixed effects model based on a panel data of foreign direct investment (FDI) flows within the EU-15 shows that horizontal investment promotes the diffusion of the production process across the national border. Specifically, our results suggest that economic convergence ensured by belonging to the common currency area helps double FDI flows.economic integration, gravity model, endogenous optimum currency area

    Southern African Economic Integration: Evidence from an Augmented Gravity Model

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    This paper investigates the feasibility of creating a common-currency union consisting of 16 countries in Southern Africa. We estimate an augmented-gravity model that includes public deficit, public debt, public expenditure, inflation, and the foreign reserves position. We also integrate Africa-specific variables such as existing economic blocs in the region, colonial heritage, and the convergence of living standards. Our analysis shows that the prospect for further integration in Southern Africa is promising, but many challenges still persist. The existing economic blocs can provide a first stepping stone to a larger currency union, but countries continuously have to cultivate good governance and fiscal discipline.optimum currency area, gravity model, Southern African integration, endogenous optimum currency area theory

    Testing mundell's intuition of endogenous OCA theory

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    This paper presents an empirical assessment of the endogenous optimum currency area theory. Frankel and Rose (1998) study the endogeneity of a currency union through the lens of international trade flows. Our study extends Frankel and Rose's model by using FDI flows to test the original theory developed by Mundell in 1973. A gravity model is used to empirically assess the effectiveness of the convergence criteria by examining location specific advantages that guide multinational investment within the European Union. A fixed effects model based on a panel data of foreign direct investment (FDI) flows within the EU-15 shows that horizontal investment promotes the diffusion of the production process across the national border. Specifically, our results suggest that economic convergence ensured by belonging to the common currency area helps double FDI flows

    Southern African economic integration: evidence from an augmented gravity model

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    This paper investigates the feasibility of creating a common-currency union consisting of 16 countries in Southern Africa. We estimate an augmented-gravity model that includes public deficit, public debt, public expenditure, inflation, and the foreign reserves position. We also integrate Africa-specific variables such as existing economic blocs in the region, colonial heritage, and the convergence of living standards. Our analysis shows that the prospect for further integration in Southern Africa is promising, but many challenges still persist. The existing economic blocs can provide a first stepping stone to a larger currency union, but countries continuously have to cultivate good governance and fiscal discipline

    Short horizons and obesity futures: Disjunctures between public health interventions and everyday temporalities

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    This paper examines the spatio-temporal disjuncture between ‘the future’ in public health obesity initiatives and the embodied reality of eating. Drawing upon ethnographic fieldwork in a disadvantaged community in South Australia (August 2012–July 2014), we argue that the future oriented discourses of managing risk employed in obesity prevention programs have limited relevance to the immediacy of poverty, contingencies and survival that mark people's day to day lives. Extending Bourdieu's position that temporality is a central feature of practice, we develop the concept of short horizons to offer a theoretical framework to articulate the tensions between public health imperatives of healthy eating, and local ‘tastes of necessity’. Research undertaken at the time of Australia's largest obesity prevention program (OPAL) demonstrates that pre-emptive and risk-based approaches to health can fail to resonate when the future is not within easy reach. Considering the lack of evidence for success of obesity prevention programs, over-reliance on appeals to ‘the future’ may be a major challenge to the design, operationalisation and success of interventions. Attention to local rather than future horizons reveals a range of innovative strategies around everyday food and eating practices, and these capabilities need to be understood and supported in the delivery of obesity interventions. We argue, therefore, that public health initiatives should be located in the dynamics of a living present, tailored to the particular, localised spatio-temporal perspectives and material circumstances in which people live.Megan Warin, Tanya Zivkovic, Vivienne Moore, Paul R. Ward, Michelle Jone

    Spin injection in Silicon at zero magnetic field

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    In this letter, we show efficient electrical spin injection into a SiGe based \textit{p-i-n} light emitting diode from the remanent state of a perpendicularly magnetized ferromagnetic contact. Electron spin injection is carried out through an alumina tunnel barrier from a Co/Pt thin film exhibiting a strong out-of-plane anisotropy. The electrons spin polarization is then analysed through the circular polarization of emitted light. All the light polarization measurements are performed without an external applied magnetic field \textit{i.e.} in remanent magnetic states. The light polarization as a function of the magnetic field closely traces the out-of-plane magnetization of the Co/Pt injector. We could achieve a circular polarization degree of the emitted light of 3 % at 5 K. Moreover this light polarization remains almost constant at least up to 200 K.Comment: accepted in AP

    Extending the limits of globule detection -- ISOPHOT Serendipity Survey Observations of interstellar clouds

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    A faint I170=4I_{\rm 170}=4 MJysr1^{-1} bipolar globule was discovered with the ISOPHOT 170 μ\mum Serendipity Survey (ISOSS). ISOSS J 20246+6541 is a cold (Td14.5T_{\rm d}\approx 14.5 K) FIR source without an IRAS pointsource counterpart. In the Digitized Sky Survey B band it is seen as a 3\arcmin size bipolar nebulosity with an average excess surface brightness of 26\approx 26 mag/\square \arcsec . The CO column density distribution determined by multi-isotopic, multi-level CO measurements with the IRAM-30m telescope agrees well with the optical appearance. An average hydrogen column density of 1021\approx 10^{21}cm2^{-2} was derived from both the FIR and CO data. Using a kinematic distance estimate of 400 pc the NLTE modelling of the CO, HCO+^+, and CS measurements gives a peak density of 104\approx 10^4cm3^{-3}. The multiwavelength data characterise ISOSS 20246+6541 as a representative of a class of globules which has not been discovered so far due to their small angular size and low 100μ\mu m brightness. A significant overabundance of 13^{13}CO is found X(13CO)150×X(C18O)X(^{13}CO) \ge 150\times X(C^{18}O). This is likely due to isotope selective chemical processes.Comment: 5 pages, 3 figure

    Unveiling the Circumstellar Envelope and Disk: A Sub-Arcsecond Survey of Circumstellar Structures

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    We present the results of a 2.7 mm continuum interferometric survey of 24 young stellar objects in 11 fields. The target objects range from deeply embedded Class 0 sources to optical T Tauri sources. This is the first sub-arcsecond survey of the 2.7 mm dust continuum emission from young, embedded stellar systems. The images show a diversity of structure and complexity. The optically visible T Tauri stars (DG Tauri, HL Tauri, GG Tauri,and GM Aurigae) have continuum emission dominated by compact, less than 1", circumstellar disks. The more embedded near-infrared sources (SVS13 and L1551 IRS5) have continuum emission that is extended and compact. The embedded sources (L1448 IRS3, NGC1333 IRAS2, NGC1333 IRAS4, VLA1623, and IRAS 16293-2422) have continuum emission dominated by the extended envelope, typically more than 85%. In fact, in many of the deeply embedded systems it is difficult to uniquely isolate the disk emission component from the envelope extending inward to AU size scales. All of the target embedded objects are in multiple systems with separations on scales of 30" or less. Based on the system separation, we place the objects into three categories: separate envelope (separation > 6500 AU), common envelope (separation 150-3000 AU), and common disk (separation < 100 AU). These three groups can be linked with fragmentation events during the star formation process: separate envelopes from prompt initial fragmentation and the separate collapse of a loosely condensed cloud, common envelopes from fragmentation of a moderately centrally condensed spherical system, and common disk from fragmentation of a high angular momentum circumstellar disk.Comment: 47 Pages, 18 Figures, ApJ accepte

    A submillimetre survey of the kinematics of the Perseus molecular cloud: I. data

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    We present submillimetre observations of the J = 3-2 rotational transition of 12CO, 13CO and C18O across over 600 sq arcmin of the Perseus molecular cloud, undertaken with HARP, a new array spectrograph on the James Clerk Maxwell Telescope. The data encompass four regions of the cloud, containing the largest clusters of dust continuum condensations: NGC 1333, IC348, L1448 and L1455. A new procedure to remove striping artefacts from the raw HARP data is introduced. We compare the maps to those of the dust continuum emission mapped with SCUBA (Hatchell et al. 2005) and the positions of starless and protostellar cores (Hatchell et al. 2007a). No straightforward correlation is found between the masses of each region derived from the HARP CO and SCUBA data, underlining the care that must be exercised when comparing masses of the same object derived from different tracers. From the 13CO/C18O line ratio the relative abundance of the two species ([13CO]/[C18O] ~ 7) and their opacities (typically tau is 0.02-0.22 and 0.15-1.52 for the C18O and 13CO gas respectively) are calculated. C18O is optically thin nearly everywhere, increasing in opacity towards star-forming cores but not beyond tau(C18O)~0.9. Assuming the 12CO gas is optically thick we compute its excitation temperature (around 8-30 K), which has little correlation with estimates of the dust temperature.Comment: 20 pages, 15 figures, accepted for publication by MNRA
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