Real Business Cycles in Emerging Countries

This dissertation investigates the sources of real business cycle fluctuations in emerging countries, using a combination of real business cycle theory and econometric techniques. The first chapter consists of two main sections. In the first section, I empirically evaluate the canonical dynamic stochastic general equilibrium model of a small open emerging economy using bayesian methods. I show that estimated dynamic models of business cycles in emerging countries deliver counterfactual predictions for the country risk premium. In particular, the country interest rate predicted by these models is acyclical or procyclical, whereas it is countercyclical in the data. The second section proposes and estimates a small open economy model of the emerging-market business cycle in which a time-varying country risk premium emerges endogenously through a variant of the financial accelerator mechanism as in Bernanke, Gertler, and Gilchrist (1999). In the proposed model, a firm's borrowing rate adjusts countercyclically as the productivity default threshold depends on the state of the macroeconomy. I econometrically estimate the proposed model and find that it can account for the volatility and the countercyclicality of the country risk premium as well as for other key emerging market business cycle moments. Time varying uncertainty in firm specific productivity contributes to delivering a countercyclical default rate and explains more than 65 percent of the variances in the trade balance and in the country risk premium. Finally, I find that the predicted contribution of nonstationary productivity shocks in explaining output variations falls between the high estimate reported by Aguiar and Gopinath (2007) and the low estimates reported by Garcia-Cicco, Pancrazi, and Uribe (2010). In the second chapter, I investigate the extent to which global financial conditions contribute to the macroeconomic fluctuations in emerging economies. Using a panel structural VAR model, I find that global risk shocks are important contributors to the dynamics of the country risk premium and real macroeconomic variables. In particular, I find that global risk shocks explain about 20 percent of movements both in the country risk premium and in the economic activity in emerging economies. The contribution of U.S. real interest rate shocks to macroeconomic fluctuations in emerging economies is negligible. I argue that the role of U.S. interest rate shocks in driving the business cycles in emerging economies, as emphasized in the previous literature, is taken up by global risk shocks. The country risk premium shock also has significant explanatory power of emerging economy real business cycle fluctuations. Global financial shocks altogether account for about 45 percent of the aggregate fluctuations in emerging economies. I find that domestic macroeconomic variables including domestic banking sector risk have sizable impact on the country risk premium fluctuations. I argue that the linkage between the economic activity and the country risk premium is the key mechanism through which global risk shocks are transmitted to emerging economies

The Effectiveness of Foreign Exchange Interventions for the Turkish Economy : A Post-Crisis Period Analysis

This study has two purposes. First, it attempts to improve the literature on foreign exchange interventions of the central banks for the emerging market economies, which have not been studied in details. The Turkish economy in the post-crisis period constitutes a good example in this context. Second, it proposes a new methodology, a time-varying parameter model, to analyze the effectiveness of the foreign exchange interventions. When the results from such an exercise are compared with the ones obtained from an event-study analysis, we find that the purchase-based interventions seem to be successful especially after the financial markets were stabilized. In that sense, we detect an asymmetry regarding the effectiveness of interventions. About the relationship between the interest rates and the exchange rates, we find that the uncovered interest rate parity condition operates in an unconventional way supporting the views put forth by the new emerging markets literature.Foreign Exchange Interventions, Emerging Markets, Event Study and Time Varying Parameter Model

Causes and Effectiveness of Foreign Exchange Interventions for the Turkish Economy

Foreign exchange rate interventions of the central banks for the emerging market economies are studied only to a limited extent. However, due to the different characteristics of these economies, especially in terms of the exchange rate dynamics, such an analysis can reveal important information. This study analyzes both the causes and the effectiveness of foreign exchange interventions of the Central Bank of the Republic of Turkey in the post-crisis period. We find that, as officially stated by the Central Bank, the main motivation behind the interventions is the excessive volatility in the exchange rate. Regarding the effectiveness of the interventions, the large and isolated purchase-based interventions seem to be effective in decreasing the volatility in the exchange rate.Foreign Exchange Interventions, Emerging Markets, Probit Analysis, and GARCH Models

Dolarizasyon Endeksleri : Turkiye’deki Dolarizasyon Surecine Iliskin Gostergeler

Dollarization, which can be considered as a wide-spread characteristic of the emerging market economies, is caused by economic units’ holding assets in foreign currency to prevent the value of their financial assets from the risk of devaluation of the national currency and to diversify their portfolio when the asset side of the balance sheets is considered. On the other hand, when the liability side of the balance sheets are considered, firms’, households’ and the government’s borrowing in foreign currency both from domestic and foreign sources causes dollarization. This paper constructs asset, liability and composite dollarization indices as indicators of the lasting dollarization process in Turkey, proposing measures for the degree of dollarization of the Turkish economy. All indices justify the success of the stabilization program that has been conducted since 2002, in reversing the dollarization trend.composite dollarization index, asset dollarization, liability dollarization

Devlet Ic Borclanma Senetleri Icin Getiri Egrisi Tahmini

Piyasa katilimcilarinin faiz beklentilerini yansitan getiri egrisinin tahmini mali analizin temel taslarindandir. Bu makalede getiri egrilerinin temel ozelliklerini tanitip, bilgimiz dahilinde ilk defa, Turkiye için uzun vadeli sabit kuponlu bonolarin da tahmine dahil edildigi yuksek frekansta getiri egrisi tahminleri sunuyoruz. Gunluk olarak tahmin edilen bu getiri egrileri piyasa katilimcilarinin makroekonomik gelismelere tepkilerini olcmek için uygun araclardir. Bu makalede getiri egrilerinden elde edilen sabit vadeli faizlerin para politikasi, enflasyon verisi açiklamasi, stopaj oranlarinin degismesi gibi olaylara verdikleri tepkiler vaka calismasi ornekleri olarak sunulmustur.

Magnetic resonance imaging based kidney volume assessment for risk stratification in pediatric autosomal dominant polycystic kidney disease

IntroductionIn the pediatric context, most children with autosomal dominant polycystic kidney disease (ADPKD) maintain a normal glomerular filtration rate (GFR) despite underlying structural kidney damage, highlighting the critical need for early intervention and predictive markers. Due to the inverse relationship between kidney volume and kidney function, risk assessments have been presented on the basis of kidney volume. The aim of this study was to use magnetic resonance imaging (MRI)-based kidney volume assessment for risk stratification in pediatric ADPKD and to investigate clinical and genetic differences among risk groups.MethodsThis multicenter, cross-sectional, and case-control study included 75 genetically confirmed pediatric ADPKD patients (5–18 years) and 27 controls. Kidney function was assessed by eGFR calculated from serum creatinine and cystatin C using the CKiD-U25 equation. Blood pressure was assessed by both office and 24-hour ambulatory measurements. Kidney volume was calculated from MRI using the stereological method. Total kidney volume was adjusted for the height (htTKV). Patients were stratified from A to E classes according to the Leuven Imaging Classification (LIC) using MRI-derived htTKV.ResultsMedian (Q1-Q3) age of the patients was 6.0 (2.0–10.0) years, 56% were male. There were no differences in sex, age, height-SDS, or GFR between the patient and control groups. Of the patients, 89% had PKD1 and 11% had PKD2 mutations. Non-missense mutations were 73% in PKD1 and 75% in PKD2. Twenty patients (27%) had hypertension based on ABPM. Median htTKV of the patients was significantly higher than controls (141 vs. 117 ml/m, p = 0.0003). LIC stratification revealed Classes A (38.7%), B (28%), C (24%), and D + E (9.3%). All children in class D + E and 94% in class C had PKD1 variants. Class D + E patients had significantly higher blood pressure values and hypertension compared to other classes (p > 0.05 for all).DiscussionThis study distinguishes itself by using MRI-based measurements of kidney volume to stratify pediatric ADPKD patients into specific risk groups. It is important to note that PKD1 mutation and elevated blood pressure were higher in the high-risk groups stratified by age and kidney volume. Our results need to be confirmed in further studies

Overview of diagnosis and management of paediatric headache. Part I: diagnosis

Headache is the most common somatic complaint in children and adolescents. The evaluation should include detailed history of children and adolescents completed by detailed general and neurological examinations. Moreover, the possible role of psychological factors, life events and excessively stressful lifestyle in influencing recurrent headache need to be checked. The choice of laboratory tests rests on the differential diagnosis suggested by the history, the character and temporal pattern of the headache, and the physical and neurological examinations. Subjects who have any signs or symptoms of focal/progressive neurological disturbances should be investigated by neuroimaging techniques. The electroencephalogram and other neurophysiological examinations are of limited value in the routine evaluation of headaches. In a primary headache disorder, headache itself is the illness and headache is not attributed to any other disorder (e.g. migraine, tension-type headache, cluster headache and other trigeminal autonomic cephalgias). In secondary headache disorders, headache is the symptom of identifiable structural, metabolic or other abnormality. Red flags include the first or worst headache ever in the life, recent headache onset, increasing severity or frequency, occipital location, awakening from sleep because of headache, headache occurring exclusively in the morning associated with severe vomiting and headache associated with straining. Thus, the differential diagnosis between primary and secondary headaches rests mainly on clinical criteria. A thorough evaluation of headache in children and adolescents is necessary to make the correct diagnosis and initiate treatment, bearing in mind that children with headache are more likely to experience psychosocial adversity and to grow up with an excess of both headache and other physical and psychiatric symptoms and this creates an important healthcare problem for their future life