Final project for ECON 409 (Public Policy Analysis)
This project estimates the marginal propensity to consume (MPC) in the U.S. economy by modeling Real Personal Consumption Expenditures as a function of Real Disposable Personal Income, using FRED data accessed via API. Benchmark, ARIMA, ETS, and linear regression models were compared on in-sample and out-of-sample forecast accuracy, with the regression specification estimating an MPC of 0.75 (R² = 0.87) and providing the most theoretically grounded medium- and long-horizon forecasts. While a random walk with drift produced stronger short-term predictions, the regression model was ultimately selected for its ability to recover an economically meaningful income-consumption relationship rather than purely mechanical forecast accuracy.
fredr (FRED API access)fable, fabletools, forecast (ARIMA, ETS, benchmark time-series models)Data is pulled live from the FRED API (series PCEC96 and DSPIC96) rather than committed to the repo. To reproduce, set an environment variable FRED_API_KEY with your own FRED API key (free to request) before knitting the .Rmd file.
us-consumption-forecasting.html — knitted final report (viewable in-browser)us-consumption-forecasting.Rmd — R Markdown source code (add this if you’re including your source)