Public Debt, Investment, and Growth: The DIG and DIGNAR Models

This online course, presented by the Institute for Capacity Development and the Research Department, explains how to analyze the relation between public investment, growth, and public debt dynamics, using two dynamic structural models: the Debt, Investment, and Growth (DIG) model and the Debt, Investment, Growth and Natural Resources (DIGNAR) model. The course presents and discusses the key pieces of these models (the investment-growth nexus, the fiscal adjustment, and the private sector response) and their interactions, which helps understand and assess the macroeconomic effects of public investment scaling-up plans, including on growth and debt dynamics. It elaborates on important factors that may shape these effects such as the type of fiscal financing, the rate of return of public capital, the efficiency of public investment, and the capacity of governments to mobilize revenues.