https://jem.semnan.ac.ir/ Journal of Econometric Modelling en daily 1 Fri, 22 May 2026 00:00:00 +0330 Fri, 22 May 2026 00:00:00 +0330 https://jem.semnan.ac.ir/article_9988.html One of the most critical factors in the growth and expansion of knowledge-based companies within the economy is access to appropriate financial resources. The primary objective of this study is to provide empirical evidence on the performance of knowledge-based firms in relation to three key financing methods: retained earnings, equity issuance, and debt financing. This is an applied research in terms of purpose, covering the period from 2011 to 2021. The models are estimated using a dynamic Bayesian time-varying coefficient panel data approach. The findings indicate that firm size has a positive effect on all types of financing; debt has a negative effect on most types of financing (except for equity issuance); and net fixed assets show a pattern of initial positive impact followed by a negative impact across all financing approaches. Additionally, the profitability-to-assets ratio initially exerts a positive influence on financing, which turns negative toward the end of the study period. https://jem.semnan.ac.ir/article_10202.html This study presents a new index for measuring income inequality based on the ratio of the median income of low-income to high-income groups. Given the common challenges in income data, including the presence of outliers and asymmetric distributions, conventional mean-based indices often do not provide appropriate estimates. In contrast, the proposed index, by utilizing the median—a measure robust to outliers—mitigates this challenge.  By precisely defining the new index and introducing the related “inequality curve,” the present study examines the basic features of a valid inequality measure and provides a consistent estimator for it. The performance of the index has been evaluated through simulation studies and application to Iranian household income data. The findings indicate that the proposed index is not only a valid measure for measuring inequality, but also provides a more expressive and practical understanding of the Lorenz curve through the related curve. https://jem.semnan.ac.ir/article_10268.html The shadow economy is a part of the economic activities of countries, the growth of which is accompanied by the expansion of illegal activities, the reduction of government revenues, and political and social instability. This paper examines the causes and consequences of the shadow economy in the provinces of Iran during the years 2000-2022 using the Multiple Causes - Multiple Indicators (MIMIC) model. The results from the model estimation show that, first, tax burden, unemployment rate, inflation rate, government size, budget deficit and per capita income have a significant effect on the growth of the shadow economy. Second, the trend of the shadow economy in Iran’s provinces, especially in recent years, is upward. These results indicate that government performance at the macro level and prevailing economic conditions in society affect the shadow economy at the local economic level. Therefore, reforming government policies and reducing the size of the government with the aim of strengthening local economies can be effective in controlling its size.          https://jem.semnan.ac.ir/article_10434.html Income inequality is one of the fundamental challenges in Middle East and North Africa (MENA) countries, with wide-ranging economic, social, and political implications. Using data from 2008 to 2021 and applying the Dynamic Ordinary Least Squares (DOLS) method across six separate models, this study investigates the impact of political stability and components of frontier technology adoption on income inequality in 17 MENA countries. The results indicate that political stability has a negative and significant effect on income inequality, whereas the adoption of frontier technologies—particularly information and communication technologies and workforce skills—exacerbates inequality. In contrast, research and development activities, industrial development, and financial access reduce income inequality. Moreover, natural resource rents, government expenditures, foreign direct investment, and unemployment each have a positive and significant effect on widening inequality. These findings suggest that policies aimed at strengthening political stability and ensuring the optimal management of frontier technology adoption and natural resources can contribute to reducing income inequality and promoting economic justice in the MENA region. https://jem.semnan.ac.ir/article_10549.html Economic, institutional, and policy uncertainties have become major challenges for industrial activities in East Azerbaijan Province in recent years, affecting firms’ operations and decision making in areas such as production planning, investment, and the procurement of raw materials. This study aims to identify and rank the critical factors contributing to uncertainty in the automotive, food, mineral, and chemical industries of the province. To achieve this, the fuzzy Delphi method—combining fuzzy logic with the multi stage Delphi process—was employed to enable the analysis of qualitative data and expert consensus. A questionnaire was distributed to 40 industrial managers and specialists, and the responses of 19 participants were analyzed. The results indicate that exchange rate volatility, sanctions, international trade policies, regulatory stability, inflation, and emerging technologies play the most significant roles in shaping industrial uncertainty. The findings highlight the need for targeted management of these factors and enhanced collaboration among governmental, private, and research sectors to reduce risks and strengthen industrial resilience. https://jem.semnan.ac.ir/article_10569.html The shock of international sanctions has been one of the most serious challenges to the stability and profitability of Iran's banking system over the past decade. This study aims to investigate the heterogeneous effect of this shock on the profitability of Iranian banks and analyze their conditional resilience using the quantile regression method. To this end, annual panel data from 19 banks over the period 2011–2023 were collected, and the model was estimated at five quantiles (0/1, 0/25, 0/5, 0/75, and 0/9). The results confirm significant heterogeneity in banks' responses. While the sanctions shock had no significant impact on the profitability of low-profit and median banks, highly profitable banks experienced a significant 0/54% increase in profitability, indicating their higher level of resilience and adaptive capacity in the face of external shocks. Furthermore, asset efficiency was identified as the strongest internal factor positively influencing profitability across the entire conditional distribution. The findings carry important policy implications. The primary recommendation is to adopt a differentiated regulatory approach based on the risk and resilience level of each bank. For low-profit banks, mandatory strengthening of capital buffers and active asset quality management should be prioritized. For resilient, high-profit banks, incentive-based frameworks can be designed to foster interbank market development and income diversification. At the macro level, enhancing transparency, improving data governance, and formulating sanctions shock scenarios to assess systemic resilience are deemed essential. https://jem.semnan.ac.ir/article_10613.html This study, within the framework of the Quantum Deep Learning (QDL) approach and utilizing the Quantum Long Short‑Term Memory (QLSTM) model, forecasts the future price of West Texas Intermediate (WTI) crude oil. Given the strategic role of oil in the global economy and the impact of its fluctuations on macroeconomic indicators, developing accurate forecasting models is of great importance for policymakers, investors, and market participants. Daily WTI crude oil futures price data from January 2003 to June 2025 are used. The QLSTM model, which combines deep learning capabilities with quantum computing, is compared with six alternative models: classical time series models (AR, MA), machine learning algorithms (SVR), and traditional deep learning models (LSTM, GRU, MLP). Results show that QLSTM achieves the lowest forecast errors (MSE, RMSE, and Theil’s U) compared to the other models, and the Diebold‑Mariano test statistically confirms its superiority. The findings indicate that QLSTM, by exploiting unique features of quantum computing such as superposition and entanglement, has a high ability to identify complex patterns and extreme volatility in the oil market. These results have important implications for Iranian policymakers in risk management, budgeting, and energy policy design, and also open new avenues for future research. https://jem.semnan.ac.ir/article_10669.html This study investigates the network structure of Iranian banks and the mechanism of risk transmission among them. Focusing on the role of key banks, it aims to provide a deeper understanding of the dynamics of systemic interconnectedness within the country’s financial system. Given the bank-based nature of Iran’s economy and the limited development of alternative financial markets, an accurate understanding of interbank interactions is crucial for enhancing financial stability. To this end, the study employs the R²-decomposed connectedness approach, which allows for the separation of contemporaneous and lagged effects. Analysis of daily data from 11 listed banks over the period February 2020 to April 2025 (corresponding to Bahman 1398 to Farvardin 1404) reveals that approximately 40 percent of the total variance in the system stems from interbank interconnectedness. The dynamic results indicate that the intensity of connectedness varies over time and increased markedly during the second half of 2023 (1402 in the Persian calendar). This surge largely coincided with the depreciation of the national currency, accelerating inflation, contractionary monetary policies by the Central Bank, rising interbank interest rates, and a liquidity crisis driven by fiscal imbalances. During this period, larger banks such as Bank Saderat and Bank Tejarat played a dominant role in transmitting shocks, whereas smaller banks primarily acted as receivers of disturbances. From a practical perspective, the findings suggest that understanding the time-varying nature of interbank connectedness can help policymakers and portfolio managers identify systemic nodes, assess risk comovements, and design more effective diversification strategies. In particular, excessive portfolio concentration in centrally positioned banks may amplify systemic risk during periods of financial stress. Overall, the results demonstrate that Iran’s banking network is dynamic and highly sensitive to macroeconomic developments, and that analyzing the temporal dynamics of connectedness offers a valuable tool for predicting and managing systemic risk. https://jem.semnan.ac.ir/article_10670.html This paper systematically analyzes the role of formal and informal institutions in shaping entrepreneurial activity dynamics, and specifically examines the distinction between entrepreneurial opportunities and entrepreneurship in the context of different stages of economic development. In theoretical theories of institutional economics, formal institutions include property rights, business regulations and freedoms, financial freedoms, and government support policies, and informal institutions include cultural norms, social networks, public trust, and fear of failure, and are analyzed simultaneously. Using a panel of 85 countries over the period 2010-2023 and based on the World Economic Forum classification, the present study separates countries into economic groups based on factors of production, efficiencies, and innovation-oriented factors to create structural heterogeneity due to institutionalization. The results of the fixed model values ​​and generalized moment methods suggest that in innovation-driven economies, strengthening formal institutions, especially business freedom and property rights, significantly stimulates the expansion of opportunistic entrepreneurship and high-growth entrepreneurial activities. In contrast, in factor-driven economies, the weakness of institutions allows informal institutions and social networks to play a compensatory and dominant role in shaping imperative entrepreneurship and the continuity of economic activities. The social and innovative findings of the research show that institutional asymmetry, meaning the mismatch between formal rules and informal norms significantly weakens the likelihood of the expansion of informal entrepreneurship and the need to increase the data and effectiveness of formal support policies for entrepreneurship. This article presents empirical evidence based on the alignment of formal institutional reforms with cultural and social contexts and provides clear policy implications for developing livelihood entrepreneurship into productive entrepreneurship and creating growth in economies today.