The Long Term Growth Model


About the Model

The Long Term Growth Model (LTGM) is an Excel-based tool to analyze long-term growth scenarios building on the celebrated Solow-Swan Growth Model. The tool can also be used to assess the implications of growth (and changes in inequality) for poverty rates. The focus of the tool is on simplicity, transparency and ease-of-use: there are no macros, and the very low data requirements mean the tool can be applied in almost any country. The tool is useful for planning/vision documents and country reports, but is not designed for short-term forecasting. The building blocks of growth are savings, investment and productivity, but the model also analyzes human capital, demographics, the external sector (external debt, FDI, CAB) and labor force participation by gender.


Latest version: LTGM v4.21 (Excel file)

Model description (pdf file)

Presentation Slides  (pdf file)

Instructions and Worked Example Simulations (pdf file)

Note that example simulations are purely illustrative and do not necessarily reflect the views of the World Bank.

The LTGM is regularly updated so check back for new versions. Last updated: 12 September 2018


Some examples of publicly available reports or working papers that used the LTGM (including early variants):

The LTGM is the product of a collaboration between the Development Research Group’s Macroeconomics and Growth Team and the Macroeconomics, Trade and Investment Global Practice.


Steven Pennings


Norman Loayza

Lead Economist