"Comparing alternative methods to estimate gravity models of bilateral trade"

The gravity equation has been traditionally used to predict trade flows across countries. However, several problems related with its empirical application still remain unsolved. In this paper, I provide a survey of the recent literature concerning the specification and estimation methods of this equation. In addition, I compare the performance of two widely extended estimators, panel OLS and Poisson Pseudo Maximum Likelihood (PPML), for a dataset covering 80% of world trade.International trade, Gravity model, Estimation methods

Comparing alternative methods to estimate gravity models of bilateral trade

The gravity equation has been traditionally used to predict trade flows across countries. However, several problems related with its empirical application still remain unsolved. In this paper, I provide a survey of the recent literature concerning the specification and estimation methods of this equation. In addition, I compare the performance of two widely extended estimators, panel OLS and Poisson Pseudo Maximum Likelihood (PPML), for a dataset covering 80% of world trade

EMU impact of on third countries' exports: a gravity approach

In this article we explore the impact of the euro adoption and the effect of the volatility of the real exchange rate on trade both on intra EMU trade and on EMU trade with third countries. To this end, we use a large database covering 93% of world trade that includes 80 countries during the period 1980-2009. We estimate a gravity equation using one of the most complete specifications in the literature to isolate the euro effect from other factors affecting trade, as regional trade agreements or exchange rate volatility. Our results show that the elimination of the volatility boosted export per se especially before 1999 and therefore, the possibility to peg to the euro could boost trade of third countries and between these third countries.Financial support from the Spanish Ministry of Science and Innovation SEJ2007-62081, and the Regional Programs P07-SEJ-03261 and SEJ‐340 of the Regional Government of Andalusia

EMU and Trade Revisited: Long-Run Evidence Using Gravity Equations

In this paper, we present evidence of the long-run effect of the euro on trade for the twelve initial EMU countries for the period 1967–2008 from a double perspective. First, we pool all the bilateral combinations of trade flows among the EMU countries in a panel cointegration gravity specification. Second, we estimate a gravity equation for each of the EMU members vis-à-vis the other eleven partners. We apply panel cointegration techniques based on factor models that account for cross-dependence and structural breaks. Whereas the joint gravity equation provides evidence on the aggregate effect of the euro on intra-European trade, by isolating the individual countries, we assess which of the member countries have obtained a larger benefit from the euro. The results show that the euro has had a positive though small effect on trade. Belgium and Luxembourg, France and Italy are the countries more benefited from the introduction of the euro. The effects for exports to third countries are in general more moderate, and, with the exception of Greece, there is no evidence of diversion effects

The euro impact on trade: long run evidence with structural breaks

In this paper we present new evidence on the euro effect on trade. We use a data set containing all bilateral combinations in a panel of 26 OECD countries during the period 1967-2008. From a methodological point of view, we implement a new generation of tests that allow solving some of the problems derived from the non-stationary nature of the data. To this aim we apply panel tests that account for the presence of cross-section dependence as well as discontinuities in the non-stationary panel data. We test for cointegration between the variables using panel cointegration tests, especially the ones proposed by Banerjee and Carrióni- Silvestre (2010). We also efficiently estimate the long-run relationships using the CUP-BC and CUP-FM estimators proposed in Bai et al. (2009). We argue that, after controlling for cross-section dependence and deterministic trends and breaks in trade integration, the euro appears to generate lower trade effects than predicted in previous studies.Financing from Spanish MICINN [ECO2011-30260-C03-01, ECO2008-05908-C02-01 and 02/ECON and SEJ2007-62081 (E. Gómez)]. M. Camarero and C. Tamarit are members of INTECO research group funded by Generalitat Valenciana, project PROMETEO/2009/098

Is the ‘euro effect’ on trade so small after all? New evidence using gravity equations with panel cointegration techniques

In this paper we present new evidence on the aggregate effect of the euro on trade using data for 26 OECD countries for the period 1967–2008. We strive to fill the gaps present in the previous literature through a second-generation panel cointegration tests and estimators that account for both cross-section dependence in the data and discontinuities in the deterministic and the cointegrating vector in the time dimension. This approach allows us to put the adoption of the euro by EMU members in historical perspective. We argue that the creation of the EMU is best interpreted as a progression of policy changes. Once we control for all of them the euro effect decreases considerably but is still significant

EMU and intra-European trade: long-run evidence using gravity equations

In this article we present evidence of the long-run effect of the euro on exports for the twelve initial EMU countries for the period 1967-2008 from a double perspective. First, we pool all the bilateral combinations of export flows among the EMU countries in a panel cointegration gravity specification. Second, we estimate a gravity equation for each of the EMU-members vis-à-vis the other eleven partners. Whereas the joint gravity equation provides evidence on the aggregate effect of the euro on intra-European exports, by isolating the individual countries we assess which of them have obtained a larger benefit from the euro. Moreover, this strategy permits to check the robustness of the aggregate results and to find possible asymmetries. Finally, we repeat both the aggregated and individual analysis for the bilateral exports of EMU members to third countries. From an econometric point of view, we apply panel cointegration techniques based on factor models that account for cross-dependence and structural breaks

Análisis microbiológico del pulpo rojo en puertos pesqueros de Campeche, México

Objetivo. Estudiar la calidad microbiológica del pulpo rojo dado su importante impacto económico y social en la región sur-sureste de México. Material y métodos. Se tomaron muestras en diversas zonas de captura de la especie y se analizaron con pruebas bioquímicas descritas en las normas oficiales mexicanas. Se identificaron cepas pertenecientes al género Vibrio, Salmonella, coliformes fecales y E. coli O157:H7. Con el empleo del Sistema BAX, se logró la identificación de microorganismos a través de su ADN bacteriano. Los resultados obtenidos en los métodos bioquímicos y moleculares fueron contrastados. Resultados. El método estadístico de Bland-Altman indicó que ambas técnicas pueden usarse indistintamente. La prueba de McNemar demostró que ambos métodos cuentan con la misma eficacia para la identificación de patógenos (valor X2=0.5 ρ=0.4795). Conclusión. La calidad microbiológica del pulpo en la región sur-sureste de México es deficiente debido a la presencia de flora bacteriana patógena que podría representar un riesgo epidemiológico. Los índices establecidos por las normas sugieren la necesidad de aplicar técnicas de identificación eficaces y rápidas como el Sistema BAX. Este método alternativo de análisis puede coadyuvar a la implementación de estrategias efectivas que permitan cumplir con especificaciones mínimas sanitarias durante el procesamiento de los productos pesqueros, y así elevar los sistemas de control para disminuir los riesgos de brotes epidemiológicos en la región.     DOI: http://dx.doi.org/10.21149/spm.v58i4.802

Deep Sequencing of the Mexican Avocado Transcriptome, an Ancient Angiosperm with a High Content of Fatty Acids

Background: Avocado (Persea americana) is an economically important tropical fruit considered to be a good source of fatty acids. Despite its importance, the molecular and cellular characterization of biochemical and developmental processes in avocado is limited due to the lack of transcriptome and genomic information. Results: The transcriptomes of seeds, roots, stems, leaves, aerial buds and flowers were determined using different sequencing platforms. Additionally, the transcriptomes of three different stages of fruit ripening (pre-climacteric, climacteric and post-climacteric) were also analyzed. The analysis of the RNAseqatlas presented here reveals strong differences in gene expression patterns between different organs, especially between root and flower, but also reveals similarities among the gene expression patterns in other organs, such as stem, leaves and aerial buds (vegetative organs) or seed and fruit (storage organs). Important regulators, functional categories, and differentially expressed genes involved in avocado fruit ripening were identified. Additionally, to demonstrate the utility of the avocado gene expression atlas, we investigated the expression patterns of genes implicated in fatty acid metabolism and fruit ripening. Conclusions: A description of transcriptomic changes occurring during fruit ripening was obtained in Mexican avocado, contributing to a dynamic view of the expression patterns of genes involved in fatty acid biosynthesis and the fruit ripening process

Psihometrijska svojstva Upitnika općega zdravlja (GHQ-28) kod ekvadorskih studenata

Objective: To analyse the internal structure of the 28-item version of the General Health Questionnaire (GHQ-28), as well as its reliability and validity in relation to other variables in a sample of Ecuadorian university students. Method: Instrumental design with confirmatory factor analysis using weighted least square mean and variance adjusted (WLSMV) estimator, reliability and convergence and discrimination validity of the GHQ-28. Sample: 495 students (56.6% women), between 18 to 35 years old (M = 24.1 years; SD = 2.1), from three universities (59.6% public) in Ecuador. Results: The bifactor model of the GHQ-28 test has an adequate fit with χ2 = 357.81; p > .05; df = 322; χ2/df = 1.11; CFI = .991; TLI = .989; SRMR = .059; RMSEA = .015 [.000 – .023]; ωH = .93; ECV = .90; PUC = .78. The GHQ-28 is reliable and in terms of convergent validity, it correlates significantly and negatively with mental health, assessed by MHC-SF, and it is discriminant between risk and non-risk cases. Conclusion: The GHQ-28 bifactor model is replicable in Ecuadorian college students.Cilj je rada bio analiza unutarnje strukture verzije Upitnika općega zdravlja od 28 čestica (GHQ-28), kao i njegove pouzdanosti i valjanosti na uzorku ekvadorskih studenata. Primijenjena je konfirmatorna faktorska analiza, uz korištenje algoritma WLSMV (engl. weighted least square mean and variance adjusted), a izračunane su pouzdanost te konvergentna i diskriminacijska valjanost. Uzorak se sastojao od 495 studenata (56.6 % žena), starosti između 18 i 35 godina (M = 24.1 godina; SD = 2.1), polaznika triju sveučilišta u Ekvadoru (59.6 % državnih). Prema dobivenim rezultatima bifaktorski model upitnika GHQ-28 pokazuje najbolje indekse pristajanja; χ2 = 357.81; p > 0.05; df = 322; χ2/df = 1.11; CFI = .991; TLI = .989; SRMR = 0,059; RMSEA = .015 [.000 – .023]; ωH = .93; ECV = 0.90; PUC = .78. Upitnik GHQ-28 pouzdana je mjera koja u smislu konvergentne valjanosti značajno i negativno korelira s mentalnim zdravljem, procijenjenim pomoću upitnika MHC-SF, te uspješno diskriminira rizične i nerizične slučajeve. Na temelju svega navedenoga zaključuje se da bifaktorski model GHQ-28 najbolje pristaje podacima dobivenima na uzorku ekvadorskih studenata