John O. Aiyedogbon

The paper explores theoretical and practical aspects of forecasting the government debt in Ukraine. A visual analysis of changes in the amount of government debt was conducted, which has made it possible to conclude about the deepening of the debt crisis in the country. The autoregressive integrated moving average (ARIMA) is considered as the basic forecasting model; besides, the model work and its diagnostics are estimated. The EViews software package illustrates the procedure for forecasting the Ukrainian government debt for the ARIMA model: the series for stationarity was tested, the time series of monthly government debt was converted into stationary by making a number of transformations and determining model parameters; as a result, the most optimal specification for the ARIMA model was chosen.
Based on the simulated time series, it is concluded that ARIMA tools can be used to predict the government debt values.

An excessive increase in public debt characterizes the contemporary development of the global economic and financial system. The paper aims to examine the short- and long-run impact of state debt on economic growth in Nigeria. The model was estimated using an autoregressive distributed lag (ARDL) bounds testing method to co-integration for the long-run investigation. At the same time, the contemporaneous dynamics were explored using an unrestricted error correction model. The data were collected from the Central Bank of Nigeria’s statistical bulletins and annual reports, and it spanned the years from 1990 to 2020. The study uncovers evidence of a long-term link between the study variables. In addition, the study finds that all the explanatory is statistically significant. Specifically, economic growth is significant and negatively responsive to changes in external debt by 0.19% and debt servicing by 0.07%, contrary to its positive response to changes in domestic debt and exchange rate by 0.27% and 0.18%, respectively. The paper, therefore, recommends that government may consider more domestic borrowings to foreign borrowings that should only be resorted to when it is indispensable. Moreover, the government should also strive to balance loan servicing and the economic sustainability.

The average agriculture output growth between 2011–2020, which stood at 3.5% against the backdrop of over 2.6% population growth rate, accounts for the present food insecurity, hunger, and malnutrition in Nigeria. The study aims to examine the impact of population growth on food security in Nigeria with data covering 1986–2020. The study employed two models: the first model analyzed agriculture output as a function of population growth rate. The second model examined the impact of population growth and agriculture productivity on economic growth. The Cochrane-Orcutt iterative method on an ordinary least squared (OLS) was employed. The study results found that population growth had a significant impact on agriculture output. However, the paper further substantiated that economic growth is significantly and positively responsive to changes in agriculture output and population growth rate in Nigeria. Among other things, the study recommended the government consider an increase in budget allocation to the agriculture sector so as to boost food output. Finally, the government may also consider introducing a policy that would encourage small families, thereby reducing the country’s population growth rate.

The purpose of the paper is to conduct a bibliometric analysis of scientific literature on the use of blockchain technologies in accounting for the period 2013–2022 based on the use of a number of special methods and tools, including Scopus and WoS, VOSviewer, Publish or Perish, Google Trends, and Google Books Ngram Viewer. Based on the results of the bibliometric analysis of relevant scientific publications, a map of the relationships between the concepts of «blockchain» and «accounting» with other categories was formed, which allowed identifying seven clusters. Based on the results of the analysis of the evolutionary time block of blockchain technology research, it was possible to identify several main periods during which the main accents in this area changed. It has been proven that it was in 2020–2021 that the interest of researchers was directed to considering blockchains as tools for working with financial and accounting information. An analysis of the space-time dimension of bibliometric analysis in Ukraine showed that the publication activity of research on the use of blockchain technologies in accounting has intensified since the second half of 2021. Analysis using Google Books and Google Trends confirmed the absence of analogies in the dynamics of changes in search queries «blockchain» and «accounting». The use of bibliometric analysis tools allowed identifying the most relevant works by the searched terms. Relevance was mostly determined by the significance of the scientific work and the scientific cluster. On the basis of these works, key theses are presented, which will become the basis for further empirical research on the chosen topic.

The paper aims to develop scientific and methodological approach to assessing the interaction of nonperforming loans of Ukrainian banking institutions, the profitability of the banking sector and its financial stability, which will allow a more detailed assessment of the directions and degree of mutual influence of these elements. To substantiate this interaction economically and mathematically, structural equation modeling was chosen. Particularly, Statistica was chosen as a software tool to assess the adequacy of the resulting model and determine the level of statistical significance of its parameters. Six key indicators were selected as a research information base, two for each subject of research: indicators of nonperforming loans in the banking sector (the volume of nonperforming loans and the ratio of problem loans excluding capital reserves), profitability indicators of the Ukrainian banking sector (assets profit and rate of return on capital), and indicators of financial stability of the Ukrainian banking sector (regulatory capital-to-risk-weighted assets ratio and liquid assets-to-total assets ratio). For calculations, statistic data of selected indicators for 2005–2019 were used.
As a result of calculations, mathematical data were obtained that accurately described the interaction of nonperforming loans of Ukrainian banking institutions, the profitability of the banking sector and its financial stability. The adequacy of the model was verified based on the following criteria: main summary statistics (ICSF criterion, ICS criterion, discrepancy function, maximum residual cosine), noncentrality fit indices (noncentrality parameter, population noncentrality parameter, Steiger-Lind RMSEA index, McDonald noncentrality index, adjusted population Gamma index), other single sample indices (Akaike information criterion, Schwarz criterion), and a normal probability plot.

This paper contributes to clarifying the scientific debate on the impact of entrepreneurship development and wages increases on Nigeria’s macroeconomic development. The main purpose of this research is to estimate the impacts, problems, and consequences between wages growth and the growth of a long-term relationship between wages and investment. The article deals with the current state of Nigeria’s macroeconomic indicators. The methodological tools for the research are the ARDL and DOLS methods, which were used to study the relationships between the macroeconomic indicators. The research period is 1987–2019. The research empirically confirms and theoretically proves that the country operates under unstable and uncertain conditions, so it is difficult to achieve macroeconomic stability. Also, the article presents the results of the analysis, which has shown a positive and statistically significant effect of raising the minimum wages on economic growth both in the long and short term. The study results can be useful for state authorities, private sector, as well as for the researchers.

Acknowledgements
This research was prepared as a part of the Scientific Project “Modeling the Transfer of Eco-Innovations in the Enterprise-Region-State System: Impact on Ukraine’s Economic Growth and Security” (No. 0119U100364), that is financed by the state budget of Ukraine.

The article examines the current issues of managing the effectiveness of eco-innovations and their impact on the “company-region-state” system using the example of waste management in Ukraine. The goal of the article is to justify the choice of an effective eco-innovation financing strategy, in which the most significant socio-economic effect is achieved for the investor. Systematization of literary sources and approaches to solving the problems of innovation management enables to determine an appropriate strategy to support resource-efficient activities in the region considering the economic efficiency of eco-innovations. The choice of mathematically sound management decisions in the system “company-region-state” should be made in respect with the consequences for the sustainable development of the region. The article presents the developed approach to calculating the sequence of investment in the management of eco-innovations using the example of solid waste management. The research methods are based on systematic approach, decision theory, and the Bellman dynamic equation. The system of innovations concerning solid waste management in the city of Sumy was profoundly studied. The research empirically confirms that the most effective strategy is to build a waste sorting station using a separate waste collection. The results of the study also substantiate that the implementation of solid waste separate collection in the city of Sumy currently requires a change in investment approach.

Acknowledgment
This research was prepared as a part of the scientific project “Modeling the Transfer of Eco-Innovations in the Enterprise-Region-State System: Impact on Ukraine’s Economic Growth and Security” (No. 0119U100364) and “Development of fundamental principles of reproduction mechanism of the social and economic development during the Third industrial revolution” (No. 0118U003578), which were financed by the state budget of Ukraine.