Issue #4 (Volume 15 2026)

Type of the article: Research Article

Abstract
This study aims to identify the direction of Granger predictability between fiscal deficit, saving-investment gap, and external account imbalances in Jordan over the period 1976–2024. It seeks to better understand the interaction between internal macroeconomic imbalances and external sector disequilibria and their implications for long-term economic stability. To achieve this objective, the study first applied the Augmented Dickey–Fuller (ADF) unit root test, which revealed that the variables were not integrated of the same order. This finding limited the applicability of the traditional Granger causality approach. Accordingly, the study employed the Toda–Yamamoto Modified Wald (MWald) causality test, which does not require all variables to be integrated of the same order.
The empirical findings indicate significant predictive linkages between internal and external macroeconomic imbalances in Jordan. Specifically, the fiscal deficit Granger-predicts the current account, while the saving–investment gap Granger-predicts external debt. In addition, the current account, external debt, and foreign exchange reserves jointly Granger-predict the saving–investment gap, highlighting the interconnectedness between domestic and external macroeconomic conditions. The findings suggest that the relationship between internal and external imbalances in Jordan is more complex than implied by the conventional twin-deficit hypothesis and underscore the importance of the saving–investment gap as an important link between domestic and external macroeconomic conditions. Accordingly, the findings highlight the importance of coordinated macroeconomic policies for strengthening fiscal discipline, promoting domestic saving, and improving investment.

Type of the article: Research Article

Abstract
Budgetary decision-making in the defense sector involves making trade-offs between interdependent capabilities, subject to financial, operational and institutional constraints. The analysis of aggregate expenditure is insufficient to evaluate these decisions, as the impact of the allocated resources depends on their composition and the interplay between categories of expenditure. The study analyzes the budgetary headings of the Portuguese Navy between 2023 and 2025 and assesses their compatibility with an institutional utility function. To this end, possible adjusted structural model has been proposed, which includes the complementarity between maintenance and investment, the adequacy of personnel expenditure, potential performance and institutional stability. The robustness of the optimization was assessed through 200,000 Monte Carlo simulations, with simultaneous variation of parameters, thresholds and weights. Total expenditure increased by 20.66 per cent over the period, but the highest utility was achieved in 2024 (0.691554), followed by 2025 (0.683443) and 2023 (0.659761). The 2024 financial year ranked first in 91.64% of the simulations and outperformed 2023 in all configurations analyzed. However, alternative normalization of the maintenance-investment component altered the ranking to 2023 > 2024 > 2025, thereby distinguishing the model’s parametric robustness from its structural robustness. The model enables to explain budgetary commitments and test the stability of decisions, but it does not constitute a causal measure of operational readiness, efficiency or institutional risk. The model’s relevance lies in the transparent support it provides for comparing the various allocation alternatives.

Acknowledgment
This article is financed by CINAV–Navy Research Centre [CINAV–Centro de Investigação Naval].

Type of the article: Research Article

Abstract
Mistrust in the social contract between governments and citizens in emerging markets remains a significant topic of scholarly research. Hence, the study examined the influence of governance quality on informal sector tax compliance behavior in Osun State, Nigeria. Primary data were obtained through a structured questionnaire spread among 256 respondents from a total population of 710 small and medium-scale enterprises (SMEs), comprising trading associations, petty traders, and market traders, in three major commercial cities from each of the three senatorial districts in the State: Osogbo, Ilesa, and Ede. The data were analyzed using partial least squares structural equation modelling (PLS-SEM). The results revealed that governance quality, measured by factors such as control of corruption (β = 0.36; p = 0.00), regulatory effectiveness (β = 0.663; p = 0.00), and voice and accountability (β = 0.078; p = 0.00), has a positive and significant influence on tax compliance among informal sector taxpayers in Osun State. The study concluded that the pathway from governance quality to informal sector tax compliance behavior in Osun State is the following: governance systems devoid of corruption, fairness of tax regulations, accountability of governance officials in the conduct of public businesses, and free and fair elections of democratically elected government representatives.

Type of the article: Research Article

Abstract
Electronic invoicing is an important component of digital tax administration that improves tax transparency and strengthens revenue administration. This study examines the association between electronic invoicing and regional tax revenues across Kazakhstan’s regions. The analysis uses regional panel data for 16 regions covering 2010–2024 and employs fixed-effects panel regression models together with k-means cluster analysis. The empirical dataset was obtained from the reports of the State Revenue Committee of the Ministry of Finance of the Republic of Kazakhstan and the Bureau of National Statistics of the Republic of Kazakhstan. The results show that electronic invoicing is not significantly associated with regional tax revenues in either the baseline model (β = 0.039; p = 0.538) or the specification with a time trend (β = –0.024; p = 0.690). However, the specification using the shifted e-Inv indicator yields a positive and statistically significant association (β = 0.302; p = 0.047). Because e-Inv is a nationwide step dummy, this result reflects temporal robustness rather than evidence of a delayed fiscal effect. Across all model specifications, GRP per capita remains the strongest determinant of regional tax revenues (β ≈ 0.825-1.102), highlighting the central role of regional economic capacity. The cluster analysis identifies three distinct groups of regions with different fiscal and digital characteristics, illustrating substantial regional heterogeneity in Kazakhstan. The findings suggest that the association between electronic invoicing and regional tax revenues depends on model specification and broader economic conditions. In contrast, regional economic capacity remains the most robust determinant of tax revenues.

Type of the article: Research Article

Abstract
Fiscal decentralization has transferred substantial financial authority to Indonesian villages, yet whether these resources translate into measurable development progress continues to depend on the quality of local governance and institutional capacity. This study examines the determinants of perceived village-level Sustainable Development Goal (SDG) achievement by testing the mediating role of village fund optimization in the relationships among collaborative governance, human resource capacity, and local government support.
Using a quantitative, cross-sectional design, primary data were collected between September 2025 and February 2026 from 100 village officials in Kuningan Regency, West Java, Indonesia, and analyzed using partial least squares structural equation modeling (PLS-SEM), with hypothesis decisions based on 95% bias-corrected and accelerated (BCa) bootstrap confidence intervals. Collaborative governance (β = 0.650) and local government support (β = 0.451) significantly predict village fund optimization (adjusted R2 = 0.675). The direct effect of human resource capacity (β = 0.204) is not statistically distinguishable from zero. Village fund optimization is also significantly associated with perceived village SDG achievement (β = 0.762; adjusted R2 = 0.576) and mediates the relationship for collaborative governance (β = 0.495) and local government support (β = 0.343), but not for human resource capacity (β = 0.155).
These findings indicate that how village funds are managed, rather than the volume of the transfer alone, is closely associated with village officials' perceptions of progress toward village SDGs, and that this effectiveness is shaped primarily by collaborative governance and local government support rather than by human resource capacity as measured here.