Nominal Convergence Research Articles

Robust causal inference for point exposures with missing confounders

AbstractLarge observational databases are often subject to missing data. As such, methods for causal inference must simultaneously handle confounding and missingness; surprisingly little work has been done at this intersection. Motivated by this, we propose an efficient and robust estimator of the causal average treatment effect from cohort studies when confounders are missing at random. The approach is based on a novel factorization of the likelihood that, unlike alternative methods, facilitates flexible modelling of nuisance functions (e.g., with state‐of‐the‐art machine learning methods) while maintaining nominal convergence rates of the final estimators. Simulated data, derived from an electronic health record‐based study of the long‐term effects of bariatric surgery on weight outcomes, verify the robustness properties of the proposed estimators in finite samples. Our approach may serve as a theoretical benchmark against which ad hoc methods may be assessed.

Assessment of the Degree of Nominal Convergence of the Bulgarian Economy with the Economies of the European Union Member States in the Period 2017 – 2022

Assessment of the Degree of Nominal Convergence of the Bulgarian Economy with the Economies of the European Union Member States in the Period 2017 – 2022

Convergence Trends in Euro Economies: Financial Crisis Recovery and the COVID-19 Pandemic

The configurative comparative method, Dynamic Pattern Synthesis (DPS) is used to replicate previous research into the impact of the euro on economic convergence. The DPS method ensures a forensic examination of the diverse variable patterns that influence cluster memberships. As with previous research conclusions, there are multiple patterns of convergence and divergence. Consistent clusters across the time periods compared are Germany, the Netherlands, Luxembourg, and Ireland; Slovakia and Estonia; Italy, Spain, and Slovenia; and Portugal and Greece. The variable patterns most likely to influence cluster definitions are differences in GDP per capita, productivity, and investment, although there are other differing variable patterns that influence specific smaller cluster memberships and the consistency of memberships over time. Externalities undermine nominal convergence. An example is the divergence of the experience of consumer inflation between 2016 and 2022. Nevertheless, some convergence in long-term interest rates is achieved. There is also divergence in the real convergence target of GDP per capita. As regards structural changes, productivity differences widen, and investment as a percentage of GDP converges during COVID-19. The theoretical implications are that the complex dynamics between collaboration, competitive markets, and global instabilities makes convergence unlikely. Real convergence, such as reducing the distribution differences of GDP per capita, is only likely to be possible over many decades, and needs considerable government interventions. Complex systems theory informs us that limits to convergence are inevitable in dynamic systems where events bring unplanned divergences.

Cooperative distributed MPC via decentralized real-time optimization: Implementation results for robot formations

Distributed model predictive control (DMPC) is a flexible and scalable feedback control method applicable to a wide range of systems. While the stability analysis of DMPC is quite well understood, there exist only limited implementation results for realistic applications involving distributed computation and networked communication. This article approaches formation control of mobile robots via a cooperative DMPC scheme. We discuss the implementation via decentralized optimization algorithms. To this end, we combine the alternating direction method of multipliers with decentralized sequential quadratic programming to solve the underlying optimal control problem in a decentralized fashion with nominal convergence guarantees. Our approach only requires coupled subsystems to communicate and does not rely on a central coordinator. Our experimental results showcase the efficacy of DMPC for formation control and they demonstrate the real-time feasibility of the considered algorithms.

FISCAL DISCIPLINE AND REAL EXCHANGE RATE STABILITY IN A HETEROGENEOUS MONETARY UNION: THE CASE OF WAEMU

This research work aims to analyze the nominal convergence of budgetary variables resulting from the respect of the convergence criteria and the impact of convergence indicators on the exchange rate volatility inner the WAEMU members States. From that end we have conducted the empirical analysis of budgetary convergence in the WAEMU zone by using variables such are: expenditure, incomes and budgetary balances. In order to reach our goal, we have adopted the methodology used by Barro et Salai-Martin (1992) which methodology is implemented by the European Union through the work of Villien et al. (2003). This methodology is consisted of following in the course of the timing an indicator of variable dispersion which may stand as a typical margin or the variance. The results show a global trend to budgetary variables convergence. And then, we have assessed the different indicators of sigma convergence on the profitable exchange rates differential in the WAEMU zone. The model used has revealed the existence of a mechanism of correcting error between the desired exchange rate observed in the zone.

The COVID-19 pandemic and main economic convergence indicators in the EU

>The outbreak of COVID-19 pandemic caused an unprecedented global public health crisis, which led to a drastic decline in economic activity and sharp rises in government deficits and public debts. Our research aims to analyse the aggregated impact of COVID-19 pandemic on each EU country and their health systems and correlate it with the main economic convergence indicators for 2020. To this purpose, we built a composite COVID index using Principal Component Analysis, employed TOPSIS to rank the EU countries according to nominal and real convergence indicators, and correlate the index with each ranking. Our findings suggest that in the first year of the pandemic, nominal convergence indicators were more affected than real convergence indicators. Non-euro CEE countries managed to keep some of their convergence indicators at relatively sustainable levels despite having high COVID index values. Baltic and Scandinavian countries seem to have outperformed the others, the latter having an initially more relaxed approach to the restrictions imposed on the population. The risk of diverging during the pandemic crisis appears to be increasing in countries where there were imbalances prior to 2020.

The Evolution of Nominal Convergence After Accession to The European Union. The Case of Romania

Economic and Monetary Union is the result of progressive economic integration that includes collective regulation for the free movement of goods, services, labor, capital, and products. Economic and Monetary Union presupposes a common currency and market, but also a monetary policy coordinated by the European Central Bank, which has the role of ensuring economic stability. In this context, the countries wishing to join must be prepared to deal with possible economic imbalances, this being possible through the existence of a high level of economic development. Through this paper, we want to identify the evolution of the nominal convergence criteria established by the provisions of the Maastricht Treaty to identify the level of readiness of the Romanian economy for integration into the Economic and Monetary Union.

Is an Economic Integration a Stimulus for Convergence? Analysis of European Union’s Last Enlargement

This study investigates the issue of the economic integration model's stimulus for convergence between the countries. As an example, the European Union, which is a successful model of economic integration, is taken. With the last enlargement wave of the European Union, the convergence of new members that joined the Union after 2000 was analyzed. Real convergence is estimated by using log regression model and nominal convergence is analyzed with the help of Convergence Reports. The results show that participation in an economic integration and also trade openness contribute to convergence in terms of Gross Domestic Product (GDP) growth among members. Trade openness is a stimulus for convergence in GDP growth in former members and new members, apart from the crisis and recovery years (2008-2013). It can be said that being included in an economic integration has a positive effect on trade openness, GDP growth and GDP per capita. Convergence was seen in 2000-2007 and 2014-2020 periods. In the 2008-2013 period, divergence was observed. The divergence experienced during the crisis years showed that nominal convergence was not sufficient to achieve harmonized growth and to overcome the crisis. In the European Union, a more harmonized growth can be achieved if real convergence is also taken into account.

Monetary integration in South America: Elección of candidates through unsupervised machine learning

Applying Unsupervised Machine Learning techniques to a set of nominal variables (based on the optimum currency area [OCA] theory and the Maastricht Treaty criteria) and industrial indicators (based on similar production patterns), this paper aims to identify potential candidates for a monetary integration in South America (SA). The main conclusion is that, according to the clustering of the nominal and industrial indicators, the countries in best position for a hypothetical monetary integration in SA are Chile, Colombia, and Perú (and Ecuador to a lesser extent); countries that are generally members of the same cluster. This group of economies, which belong to the Pacific Alliance, are in a better position to meet various criteria for regional monetary integration, such as nominal convergence and similar production patterns.

Ready or not? Constructing the Monetary Union Readiness Index

Abstract While all EU Member States can join the group's monetary union, the euro area, some members are far more ready for the adoption and use of the single European currency. Here, we construct a new Monetary Union Readiness Index (MURI) for the EU Member States. The theoretical framework of the index is built on the economic theory of Optimal Currency Areas and EU regulations such as the Treaty and the Maastricht criteria, and the Regulation on the Macroeconomic Imbalance Procedure. The index measures (i) nominal convergence, (ii) real convergence, and (iii) macroeconomic stability. The MURI Index provides an easy to use real-time policy tool to evaluate both candidate and current euro area members. Hence, it complements, aggregates and communicates key information in annual convergence reports and in official statistics. Our evaluation finds that Austria, Finland, Denmark, Sweden and Germany showed the highest level of compliance with the different euro area criteria in 2018, while Greece, Cyprus, Romania, Spain, and Italy were the least compliant.

Retentive force of telescopic crowns combining fiber-reinforced composite and zirconia.

This study investigated changes in the retentive force of telescopic crowns fabricated by combining a zirconia primary crown and a fiber-reinforced composite (FRC) secondary crown. Primary zirconia crowns were produced with a nominal convergence angle of 0°. Forty-eight secondary crowns were milled from FRC and divided into three study groups (n=16/group) based on milling parameters and post-milling adjustment. The offset parameter used for the final milling step of the inner crown surface was adjusted for a tight initial fit in Group 1 (milling offset: +10 µm, i.e., 2 × 10 µm = 20 µm lower inner diameter compared with the CAD file of the crown) and for improved initial fit (milling offset: -10 µm, i.e., an enlargement of the inner crown diameter by 2 × 20 µm = 40 µm in relation to Group 1) in Groups 2 and 3. The inner surfaces of the secondary crowns were polished with diamond paste in Groups 1 and 2, and silicon points were used for Group 3. The retentive force was measured using a universal testing device. The secondary crown was placed on the primary crown, with the final fitting force set to a load of 100 N. This test was conducted before and after aging (10,000 insertion/removal cycles) under dry and wet conditions. A generalized linear model was used to estimate the differences in the retentive force to elucidate the effects of the milling parameters and polishing methods. We realized an initial retentive force of approximately 10 N. In Groups 2 and 3, the difference was statistically significant between the dry and wet conditions before aging (P < 0.05). There was no significant difference between the dry and wet conditions after aging in any of the groups (P > 0.05). An adequate initial retentive force can be achieved with telescopic crowns combining zirconia and FRC.

Has COVID-19 pandemic crisis changed the EU convergence patterns?

Due to the Covid-19 pandemic, governments across the EU countries had to introduce measures to close the borders, restrict the movement of people, and suspend business activities in nonessential sectors. These restrictions threatened to result in the worst economic shock since the Great Depression of the 1930s. This situation forced the EU leaders to quickly implement urgent measures in the form of stimulating packages in order to avoid a catastrophic economic collapse. The measures, however, have been implemented without coordination and insufficiently considering the solidarity principle among the Member States, which is one of the EU basic principles. In that way, the already existing gap in development among the EU economies has become even more pronounced, which will certainly have an impact on the convergence process in the EU. In that sense, this paper is aimed at analyzing the convergence process among the EU economies during the period from 2004 to 2020 and comparing differences among the EU member states during the pandemic crisis (in 2020) and the global economic crisis (in 2008). To define the policy recommendations for overcoming the crisis and for obtaining a satisfactory level of real convergence and nominal convergence, Hierarchical Agglomerative Clustering (HAC) was performed on the data for 2020 and five clusters were derived.

Cohesive Growth in Europe: A Tale of Two Peripheries

Over the last two decades, income disparities between EU member states tended to decline, particularly before the financial crisis. While Central and Eastern Europe caught up with the EU average, Southern Europe fell behind after 2009. Catch-up growth in both peripheries relied on nominal convergence (real appreciation) and foreign capital. Further growth can and should be fostered by an economic policy that does not neglect domestic demand, stabilises capital markets and invests in research, education, health and intangibles.

Green Transitioin and Nominal Convergence in the EU

Green Transitioin and Nominal Convergence in the EU

MONETARY CHALLENGES OF EMERGING EUROPEAN ECONOMIES TOWARDS THE EURO ZONE

The paper aims to highlight the main difficulties on the monetary path towards the euro zone experienced by Emerging Europe. Emerging European Economies (EEEs), EU members, adopted either double shift or smooth transition monetary approach towards the euro zone. Double shift assumes changes from floating exchange rate regimes (ERRs) to the ERM II target zone and, finally, monetary union as a rigid ERR. The smooth transition is practiced by economies with mainly rigid ERRs before the ERM II entrance and, at the end, again rigid ERR of a monetary union. Despite chosen monetary path towards the euro zone, crucial difficulties or aggravating factors could be identified in the form of real exchange rate appreciation due to productivity growth or capital inflows. A reconciliation of inflation and exchange rate target zone is extremely complex, at the same time striving not to jeopardize the real convergence. What is stressed here is the vicious cycle between real and nominal convergence as the reason why the ERM II target should be regarded as a “waiting room“ not as a “training room“ in the pre-EMU phase.

BULGARIA'S REAL CONVERGENCE IN THE CONTEXT OF POTENTIAL EMU MEMBERSHIP

Since the entry of Bulgaria into the European Union, the country's full membership in the Economic and Monetary Union has become one of the national economic policy goals. In the recent period Bulgaria fulfils all the nominal convergence criteria, except for the criterion on exchange rate stability as long as the country does not participate in the ERM II mechanism (although Bulgaria has a currency board arrangement in place since 1997 and the Bulgarian currency is pegged to the euro). Despite that, Bulgaria remains the EU member with the lowest level of GDP per capita and lowest productivity and income levels. In June 2018 the Bulgarian authorities submitted a letter of intent to the EU policy makers to join the ERM II mechanism and the banking union. In July 2020 the mutual agreement to include the Bulgarian lev in the ERM II mechanism and Bulgaria to join the banking union was achieved. In the context of the future full EMU membership it is important to assess the evolution and the state of Bulgaria's real convergence. This paper looks at the Bulgaria's real convergence, understood as the convergence of GDP per capita, labour productivity and convergence of price levels. We use the Beta and Sigma convergence methods and explore the convergence in the 1999-2018 period. We also compare Bulgaria's real convergence to the real convergence of other CEE countries that are EU members (Croatia, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia and Slovenia), part of which have already accepted the euro and the other part are still outside of the euroarea. We also try to explain the economic reasoning behind the EMU accession path of Bulgaria. The results of the survey show that Bulgaria lags behind in its convergence process from other CEE countries, but at the same time we believe that the benefits of the euroarea membership outweigh the possible negative consequences.

Sovereign debt crisis management by the European Central Bank

"Following the bursting of the real estate crisis of 2007 and the financial crisis of 2008, the European Union faced another difficult situation, namely the sovereign debt crisis, when the euro was put to the test. The sovereign debt crisis is a widely debated and analyzed topic both in Romania and in Europe. Given the effects it generates, amid rising government debt and the instability of the banking system, it is important to know its causes, in order to subsequently identify the most effective measures to improve the economic situation in each affected state. This paper seeks to discuss the concept of sovereign debt crisis by conducting an analysis of government debt sustainability and the budget deficit in the European Union, as well as a forecast of government debt sustainability in Romania, reflecting the measures implemented by the Central Bank EU. According to the Maastricht criteria, the nominal convergence indicators, including the budget deficit and government debt, must be below the alert level, so that they are in line with European Union requirements. The level of the consolidated budget deficit must be less than 3%, and in terms of government debt, it must be below 60% of GDP. The rationale for choosing this theme is that the existence of such a crisis at European level can significantly affect the economic context of each Member State of the European Union (EU), in terms of the interconnection of the global financial system. This interconnection refers to the idea that, when a state becomes involved in the claim of sovereign debt, it indisputably endangers part of the external private debt. This concept is also called in the literature and contagion effect. The relevance of this theme lies in the analysis of the evolution of the main indicators that led to the onset of the sovereign debt crisis, as well as in the identification of its causes, in order to prevent enlargement."

Risks of Global Financial Markets and the Importance of Credibility: Implications for Hungarian Fiscal Policy

The central issue in the controversy about the adoption of the euro in Hungary is the difficulties associated with the fulfillment of the fiscal criterion and the possible growth sacrifice it requires. In this paper the author examines the question whether the strategy of delaying entry into the euro-zone implies that fiscal consolidation can be delayed as well. In approaching the problem the paper considers the origins and history of the present-day global financial markets and argues that given the high degree of systemic risks individual countries face responsible macroeconomic policies are crucial in minimizing vulnerability tocrises. Consequently in order to avoid excessive interest rates and speculative inflows (or currency crisis in the worst case scenario) fiscal deficits in Hungary would have to be cut and credibility of fiscal policy reestablished even without EMU accession. The overall conclusion from this overview is that delaying entry in order to delay fiscal adjustment is likely to increase the trade off between real and nominal convergence instead of mitigating it.&#x0D; JEL classification: F33, F41, H62

Divergences in the European Union

The economic differences between the regions of the European Union are a continuous concern for both politics and economic research. Starting with 1990, the European economy, embedded in turn in the economic events that occur at global level, is entering a new era of convergence, where GDP per capita in emerging and developing countries as a whole started to outperform those of the advanced economies, from which we could draw the real convergence nature of the events. In the EU, since the EMU establishment and the implementation of the single monetary policy, nominal convergence has been and continues to be far more prominent than real convergence. This paper aims to carry out an analysis of divergences and convergences in the European Union based on research on the various theories available in the literature and on the current situations of European countries.

Macroeconomic stability as the condition for Bulgaria to join the euro area

Research background: The subject of research is the macroeconomic situation of Bulgaria in the context of the country's preparations for joining the euro area. In 2018, the Bulgarian government approved a plan of preparations covering the period until the end of June 2019, which assumes that the country will join the ERM II mechanism in July 2019, and the euro area on 1 January 2022. Bulgaria meets four nominal convergence criteria regarding inflation, long-term interest rate, budget deficit and public debt. The national currency is pegged to the euro under the currency board arrangement. Despite this, the implementation of this optimistic scenario may be difficult because since the 2007 crisis, the European institutions pay more attention to macroeconomic stability and the sustainability of convergence.&#x0D; Purpose of the article: The aim of the article is to identify the factors destabilising macroeconomic equilibrium in Bulgaria, which are a potential obstacle to the adoption of the euro by Bulgaria on schedule.&#x0D; Methods: The research was based on the changes in selected macroeconomic indicators, as well as on the method used by the European Commission to detect macroeconomic imbalances. The observation and analysis covered the 2007?2018 period. &#x0D; Findings &amp; Value added: The research results indicate that the low level of socio-economic convergence of Bulgaria and macroeconomic imbalances may delay its membership in the monetary union. Therefore, while respecting the country's aspirations to join the euro area, one cannot ignore the risk of another destabilisation of the euro area.