Estimating Central Bank Behavior in Emerging Markets: The Case of Turkey

Design of policy rules for an an emerging market central bank (EMCB) operating in an inflation-targeting framework presents additional challenges beyond those for describing the behavior of a central bank in a developed economy. Even though an inflation-targeting regime entails abolishing the exchange rate target in favor of an inflation target, it is more difficult for an EMBC to ignore movements in exchange rates given the relatively shallow depth of financial markets and the the high degree of dollarization. Additionally the EMCB may be forced to change the pursued exchange rate regime following a capital account reversal so that linear Taylor rules may be inadequate for describing EMCB reactions. We develop an empirical framework that addresses these issues and propose a new methodology to estimate unobserved variables such as expected inflation and potential output within the rule. Specifically, we employ a structural, nonlinear Kalman filter algorithm to estimate time-dependent parameters and unobserved variables, and we experiment with various exchange rate mechanisms that can be employed by an EMCB. This approach allows us to track any changes in EMCB behavior - including regime shifts - following a switch to inflation targeting. Using post-2001 data from Turkey, which is a fairly dollarized small open economy, we document that the Central Bank of Turkey has given relatively more importance to the inflation gap than to the output gap or to exchange rates, but not until some time after it had switched to an inflation-targeting framework.Dual Extended Kalman Filter, Taylor Rule, inflation targeting, emerging markets

Estimating Central Bank Behavior in Emerging Markets: The Case of Turkey

Design of policy rules for an an emerging market central bank (EMCB) operating in an inflation-targeting framework presents additional challenges beyond those for describing the behavior of a central bank in a developed economy. Even though an inflation-targeting regime entails abolishing the exchange rate target in favor of an inflation target, it is more difficult for an EMBC to ignore movements in exchange rates given the relatively shallow depth of financial markets and the the high degree of dollarization. Additionally the EMCB may be forced to change the pursued exchange rate regime following a capital account reversal so that linear Taylor rules may be inadequate for describing EMCB reactions. We develop an empirical framework that addresses these issues and propose a new methodology to estimate unobserved variables such as expected inflation and potential output within the rule. Specifically, we employ a structural, nonlinear Kalman filter algorithm to estimate time-dependent parameters and unobserved variables, and we experiment with various exchange rate mechanisms that can be employed by an EMCB. This approach allows us to track any changes in EMCB behavior - including regime shifts - following a switch to inflation targeting. Using post-2001 data from Turkey, which is a fairly dollarized small open economy, we document that the Central Bank of Turkey has given relatively more importance to the inflation gap than to the output gap or to exchange rates, but not until some time after it had switched to an inflation-targeting framework

Estimating Central Bank Behavior in Emerging Markets: The Case of Turkey

Design of policy rules for an an emerging market central bank (EMCB) operating in an inflation-targeting framework presents additional challenges beyond those for describing the behavior of a central bank in a developed economy. Even though an inflation-targeting regime entails abolishing the exchange rate target in favor of an inflation target, it is more difficult for an EMBC to ignore movements in exchange rates given the relatively shallow depth of financial markets and the the high degree of dollarization. Additionally the EMCB may be forced to change the pursued exchange rate regime following a capital account reversal so that linear Taylor rules may be inadequate for describing EMCB reactions. We develop an empirical framework that addresses these issues and propose a new methodology to estimate unobserved variables such as expected inflation and potential output within the rule. Specifically, we employ a structural, nonlinear Kalman filter algorithm to estimate time-dependent parameters and unobserved variables, and we experiment with various exchange rate mechanisms that can be employed by an EMCB. This approach allows us to track any changes in EMCB behavior - including regime shifts - following a switch to inflation targeting. Using post-2001 data from Turkey, which is a fairly dollarized small open economy, we document that the Central Bank of Turkey has given relatively more importance to the inflation gap than to the output gap or to exchange rates, but not until some time after it had switched to an inflation-targeting framework

Percentile reference values for anthropometric body composition indices in European children from the IDEFICS study

INTRODUCTION: To characterise the nutritional status in children with obesity or wasting conditions, European anthropometric reference values for body composition measures beyond the body mass index (BMI) are needed. Differentiated assessment of body composition in children has long been hampered by the lack of appropriate references. OBJECTIVES: The aim of our study is to provide percentiles for body composition indices in normal weight European children, based on the IDEFICS cohort (Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and infantS). METHODS: Overall 18 745 2.0-10.9-year-old children from eight countries participated in the study. Children classified as overweight/obese or underweight according to IOTF (N = 5915) were excluded from the analysis. Anthropometric measurements (BMI (N = 12 830); triceps, subscapular, fat mass and fat mass index (N = 11 845-11 901); biceps, suprailiac skinfolds, sum of skinfolds calculated from skinfold thicknesses (N = 8129-8205), neck circumference (N = 12 241); waist circumference and waist-to-height ratio (N = 12 381)) were analysed stratified by sex and smoothed 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentile curves were calculated using GAMLSS. RESULTS: Percentile values of the most important anthropometric measures related to the degree of adiposity are depicted for European girls and boys. Age-and sex-specific differences were investigated for all measures. As an example, the 50th and 99th percentile values of waist circumference ranged from 50.7-59.2 cm and from 51.3-58.7 cm in 4.5-to < 5.0-year-old girls and boys, respectively, to 60.6-74.5 cm in girls and to 59.9-76.7 cm in boys at the age of 10.5-10.9 years. CONCLUSION: The presented percentile curves may aid a differentiated assessment of total and abdominal adiposity in European children

Investigating the association between obesity and asthma in 6- to 8-year-old Saudi children:a matched case-control study

Background: Previous studies have demonstrated an association between obesity and asthma, but there remains considerable uncertainty about whether this reflects an underlying causal relationship. Aims: To investigate the association between obesity and asthma in pre-pubertal children and to investigate the roles of airway obstruction and atopy as possible causal mechanisms. Methods: We conducted an age- and sex-matched case–control study of 1,264 6- to 8-year-old schoolchildren with and without asthma recruited from 37 randomly selected schools in Madinah, Saudi Arabia. The body mass index (BMI), waist circumference and skin fold thickness of the 632 children with asthma were compared with those of the 632 control children without asthma. Associations between obesity and asthma, adjusted for other potential risk factors, were assessed separately in boys and girls using conditional logistic regression analysis. The possible mediating roles of atopy and airway obstruction were studied by investigating the impact of incorporating data on sensitisation to common aeroallergens and measurements of lung function. Results: BMI was associated with asthma in boys (odds ratio (OR)=1.14, 95% confidence interval (CI), 1.08–1.20; adjusted OR=1.11, 95% CI, 1.03–1.19) and girls (OR=1.37, 95% CI, 1.26–1.50; adjusted OR=1.38, 95% CI, 1.23–1.56). Adjusting for forced expiratory volume in 1 s had a negligible impact on these associations, but these were attenuated following adjustment for allergic sensitisation, particularly in girls (girls: OR=1.25; 95% CI, 0.96–1.60; boys: OR=1.09, 95% CI, 0.99–1.19). Conclusions: BMI is associated with asthma in pre-pubertal Saudi boys and girls; this effect does not appear to be mediated through respiratory obstruction, but in girls this may at least partially be mediated through increased risk of allergic sensitisation

Tin gallium oxide epilayers on different substrates: optical and compositional analysis

Electron beam techniques have been used to analyze the impact of substrate choice and growth parameters on the compositional and optical properties of tin gallium oxide [(Sn x Ga1−x)2O3] thin films grown by plasma‐assisted molecular beam epitaxy. Sn incorporation and film quality are found to be highly dependent on growth temperature and substrate material (silicon, sapphire, and bulk Ga2O3) with alloy concentrations varying up to an x value of 0.11. Room temperature cathodoluminescence spectra show the Sn alloying suppressing UV (3.3–3.0 eV), enhancing blue (2.8–2.4 eV), and generating green (2.4–2.0 eV) emission, indicative of the introduction of a high density of gallium vacancies (VGa) and subsequent VGa–Sn complexes. This behavior was further analyzed by mapping composition and luminescence across a cross section. Compared to Ga2O3, the spectral bands show a clear redshift due to bandgap reduction, confirmed by optical transmission measurements. The results show promise that the bandgap of gallium oxide can successfully be reduced through Sn alloying and used for bandgap engineering within UV optoelectronic devices

Selection of metastasis competent subclones in the tumour interior

The genetic evolutionary features of solid tumour growth are becoming increasingly well described, but the spatial and physical nature of subclonal growth remains unclear. Here, we utilize 102 macroscopic whole-tumour images from clear cell renal cell carcinoma patients, with matched genetic and phenotypic data from 756 biopsies. Utilizing a digital image processing pipeline, a renal pathologist marked the boundaries between tumour and normal tissue and extracted positions of boundary line and biopsy regions to X and Y coordinates. We then integrated coordinates with genomic data to map exact spatial subclone locations, revealing how genetically distinct subclones grow and evolve spatially. We observed a phenotype of advanced and more aggressive subclonal growth in the tumour centre, characterized by an elevated burden of somatic copy number alterations and higher necrosis, proliferation rate and Fuhrman grade. Moreover, we found that metastasizing subclones preferentially originate from the tumour centre. Collectively, these observations suggest a model of accelerated evolution in the tumour interior, with harsh hypoxic environmental conditions leading to a greater opportunity for driver somatic copy number alterations to arise and expand due to selective advantage. Tumour subclone growth is predominantly spatially contiguous in nature. We found only two cases of subclone dispersal, one of which was associated with metastasis. The largest subclones spatially were dominated by driver somatic copy number alterations, suggesting that a large selective advantage can be conferred to subclones upon acquisition of these alterations. In conclusion, spatial dynamics is strongly associated with genomic alterations and plays an important role in tumour evolution