Alper, Findik OzlemAlper, Ali ErenOzayturk, Gurcem2024-11-072024-11-072022978-981193116-1978-981193115-4https://doi.org/10.1007/978-981-19-3116-1_15https://hdl.handle.net/11480/11695The sustainability of budget deficits is one of the determining factors regarding the sustainability of economic policies. Nevertheless, the Covid-19 pandemic, which has been effective all over the world since the first days of the year 2020, caused a rise in the public expenditures of countries, whereas a decline in public revenues, and hence, budget deficits. Based on the intertemporal budget constraint approach, this study aims to investigate the sustainability of the budget deficit in the G-7 countries as well as the selected developing countries, including Brazil, Russia, South Africa, and Turkey, during the periods before and after the Covid-19 pandemic, employing the (Quintos, Journal of Business & Economic Statistics 13:409–417, 1995) methodology. In the study, where the Fourier KPSS unit root and Fourier ADL cointegration tests, which take into account both smooth and sharp structural breaks, are performed, the existence of a cointegrated relationship is examined in all countries included in the analysis, and the long-term coefficients are determined by employing the FMOLS and DOLS estimation methods. The estimation results indicate that budget deficits sustainability is in strong form merely in Germany, Japan, Russia, and Turkey throughout both periods. It is determined that the budget deficits, which were in a strong sustainable form for Italy during the pre-Covid-19 period, have transformed into a weak sustainable form throughout the pandemic period. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.eninfo:eu-repo/semantics/closedAccessBudget deficitCovid-19FourierSustainabilityBook Chapter22524610.1007/978-981-19-3116-1_152-s2.0-85161199286N/A