Estimate the optimal size of income tax, profits and capital gains (direct tax) and value-added tax on goods and services (indirect tax) In Egypt, according to the Laffer curve hypothesis In the period from (1975-2021)

Economic policy makers seek to estimate optimal tax rates that can achieve the highest level of tax revenues, which have a fundamental role in forming government revenues and financing increased government expenditures. Therefore, determining the optimal tax rate achieves the goal of increasing tax revenues that achieve the highest level of economic growth. This study aims To estimate the optimal size of direct tax represented by income tax, profits and capital gains, and indirect tax represented by value-added tax on goods and services in Egypt with the aim of increasing the tax revenue in Egypt during the period from 1975-2021 and studying the extent to which the Laffer curve hypothesis was achieved, where the non-linear relationship between tax rates and tax revenues using the threshold regression model (TR). The study reached the following results, first in general there A non-linear relationship between the tax proceeds in Egypt and each of the direct tax represented in the tax on income, profits and capital gains, and the indirect tax represented in the value-added tax on goods and services, which means that the Laffer curve hypothesis is fulfilled Secondly, taxes on income, profits, and capital gains (direct tax) have a positive impact on tax revenues in Egypt if the tax rate is less than 36.9%. This effect turns into a negative impact on tax proceeds if the tax rate on income, profits, and capital gains exceeds 36.9%. Third  Taxes on value added on goods and services (indirect tax) have a positive impact on tax revenue in Egypt before the threshold level, which is 27.5%, but after crossing the level of 27.5%, the impact of value added tax is more positive, and the study recommends those in charge of policy  Finance in Egypt is keen not to exceed tax rates on income, profits, and capital gains in Egypt, as one of the most important types of direct taxes, the barrier of 36.9%, as well as working to ensure that the tax rate on value added on goods and services, as one of the most important types of indirect taxes, exceeds the barrier of 27.5%.  Increase the tax revenue in Egypt and take the necessary measures to achieve this.