Exploring options to deepen and broaden the personal income tax base in South Africa

In this paper we explore options for augmenting South Africa's personal income tax revenue using two microsimulation models: PITMOD simulates the personal income tax system and is underpinned by a dataset comprising a full extract of anonymized individual-level administrative tax data; and SAMOD simulates personal income tax and social benefits using a nationally representative survey. We explore policy reforms at both the upper and lower ends of the income distribution of tax-registered individuals and assess the impacts on revenue and measures of progressivity. The PITMOD simulations are enhanced by introducing a behavioural element to the model and are complemented by using SAMOD to estimate the impacts of the reforms on the whole population including those who are not tax-registered.