In this paper we propose a methodology to study circular economy processes based on mathematical modelling. In open-ended systems, waste could be converted back to recycling, transforming the economy from linear to circular. The concept of entropy and the second law of thermodynamics give the argument for a scale reduction of material circulation. As humans extract more and more energy and matter for the economy, the degree of entropy is likely to increase. Based on the findings of economic studies on the implications of industrialization in the case of growing economies, this study aims at evaluating circular economy processes at the European Union (EU) level using a Shannon-Entropy-based algorithm. An entropy-based analysis was conducted for the 28 European Union countries during the time frame 2007–2016. The modelling process consists of constructing a composite indicator which is composed of a weighted sum of all indicators developed by an algorithm based on Shannon Entropy. The weights assigned to each indicator in our analysis measure the significance of each indicator involved in the development of the composite indicator. The results are similar to the international rakings, consolidating and confirming the accuracy and reliability of this approach.

In this paper, starting from the conceptual model of the rational behavior theory developed by Icek Ajzen, the authors develop a behavioral model of rational expectations of the managerial decisions in order to determine the influence of the behavior of the undertakings on a competitive environmental market. The data were collected between 1 May 2019–30 June 2019 with the help of a questionnaire addressed to the employees and managers of the companies engaged in the green procurement processes in Romania. The sample volume was 160 and the data was analyzed with partial least square structural equation modeling (PLS-SEM) method and by using the statistical software Smart-PLS 3.2.8. Starting from the relevant economic literature in the field of rational behavior, the article identifies the behavioral indicators that underlie the decision to invest in this market. These indicators are the independent variables that model the impact of rational behavioral theory on managerial decisions. The conclusions of the study confirm the theoretical aspects presented in the article, emphasizing that the managerial decisions based on rational behavior theory are the direct result of the cooperation of several factors, such as the strategic vision, innovation, regulation, and the level of competences of the human factor.

Knowledge intensive business services have recently become one of the most important themes addressed by researchers in the field. Their interest in such a subject is due primarily to the impact they have in terms of growth rate, especially for the economies of emerging countries. The literature in the field brings a series of persuasive arguments about the role that these services have both at national and regional levels. In this paper, the authors make a radiography of the Romanian research system which is passing through a transition phase from the ruins of communism to the challenges of globalization. Moreover, the authors analyse the role of performance-based services in Romania’s regional development in correlation with the economic growth target at the national scale. Quantitative methods used during the present paper highlight the disparities between Romania’s geographic regions in terms of technological development and research. In addition, the econometric model developed in the study emphasizes the cohesion degree corresponding to the European Union Member States.

Kalman filtering is a linear quadratic estimation (LQE) algorithm that uses a time series of observed data to produce estimations of unknown variables. The Kalman filter (KF) concept is widely used in applied mathematics and signal processing. In this study, we developed a methodology for estimating Gaussian errors by minimizing the symmetric loss function. Relevant applications of the kinetic models are described at the end of the manuscript.

This paper analyses the public procurement auctions for snow removal contracts to find out whether bid-rigging occurred. Due to the limited participation in the auction processes, detection of anticompetitive agreements was possible. The econometric analysis used in our study supported the findings of a cartel agreement. Cluster analysis, statistical hypothesis, normality and symmetry and nonparametric tests reveal two types of auctions: competitive and noncompetitive bids. The aim of this paper is to analyze the public procurement auctions with nonparametric statistical methods. Our findings are in line with the literature in the field.

Nowadays, over 10% of the population of the European Union is facing energy poverty. Energy poverty is defined as the situation where a consumer cannot access energy services in his household up to a socially and materially necessitated level. Although Romania is characterized, according to official European statistics, by a high number of persons at risk of poverty or social exclusion – 40.3% in 2014 – as compared to the other Member States – 24,4% for EU27 – recent studies of the European Commission show that only 12.3% of Romanians were suffering in 2014 of energy poverty. Still energy poverty is considered by several national and international institutions a major problem in Romania, just like in the other “new” EU Member States. So we ask ourselves what is energy poverty and what are the drivers of energy poverty in Romania. Energy poverty has recently drawn the attention of both academic research and policy makers, fact that has led to an mainly uncoordinated excess of national and international studies regarding this topic. This article aims to restrain the concept of energy poverty from the perspective of national and EU policies and regulations by reviewing the existing knowledge and critical approaches in this field. Also the study aims to analyse Romania’s development linked to the development of national and EU policies, laws and regulations in order identify the appropriate measures to reduce energy poverty, with regard to its main drivers and effects. Further, the paper explores possible policies that could be implemented to reduce the number of people affected by energy poverty, tailored on the specifics of the Romanian energy sector and Romania’s overall economy. Based on the findings, recommendations are drawn. The research relies on the current body of literature as well as on data available at national and at international level in this field.