U.S. Real GDP Normalized Peak Plot over last 15 Recessions (1929-2020)

Explore the progress of U.S. real GDP (GDPC1, quarterly, seasonally adjusted, $billions 2012 chained) in the first quarters of the last 15 recessions (1929-2020). [Updated October 29, 2020]


About this visualization

I (Richard Evans) first created a version of this plot using STATA in early 2009 during the Great Recession (Dec. 2007 to June 2009), which I posted and wrote about on the now defunct Econosseur.com blog. The updated dynamic visualization on this page was created using the Python prgramming language and the Bokeh plotting library. It shows U.S. real GDP (GDPC1, quarterly, seasonally adjusted, $billions of 2012 chained) during the last 15 recessions, from the Great Depression that started in 1929 to the current COVID-19 recession that started in February 2020. I take the GDPC1 level at the beginning of the recession and normalize its value to 1.0. This plot, therefore, shows the percent deviation of the GDPC1 series during each recession relative to its peak at the beginning of the recession. It is a way to compare severity and duration of recession shocks to real GDP across different recessions in different time periods.

Back in 2009, I wanted to highlight how bad the effect of the Great Recession was on U.S. output. This plot shows that the current COVID-19 recession (started Feb. 2020) has had a historic negative effect on U.S. GDP, with a 10.2% decline in the first two quarters of the recession. None of the previous 14 recessions have come close, with a 6.5% decline in the first two quarters of the Great Depression (1929-1933) being the next biggest. If you zoom out, you will see that U.S. output during the Great Depression (1929-1933) had a decline of 27.5% after 3.5 years and took a full 7 years to get back to its 1929 peak level. The Great Recession (2007-2009) took 3.5 years to get back to its peak level. This might be an indication that our current COVID-19 recession will take a long time to get back to the 2019 Q4 peak real GDP of $19.3 trillion.

The data underlying the visualization on this page default to showing GDPC1 series values in the 15 recessions from 3 quarters before the peak to 10 quarters after the peak. However, the data here are available to be viewed from 3 years before the peak to 10 years after the peak.

The quarterly GDPC1 data series begins in Q1 1947. However, annual real GDP data (GDPCA, $billions 2012 chained) are available from 1929 to 2019, from the Federal Reserve Economic Data (FRED) system. In order to have a full time series of quarterly data for all the recessions, I imputed the missing quarters for the annual data portion as a cubic spline that connected the annual data from Q3 1929 to Q1 1947. These annual data are stored as a .csv file (usgdp_anual_1929-1946.csv) in the visualization's GitHub repository. The imputation takes place in the usgdo_npp_bokeh.py file in the GitHub repository and the final GDPC1 quarterly data series from 1929-07 to 2020-04 with the annual data from 1929 to 1946 and the quarterly data from 1947 on is usgdp_2020-07-01.csv. The dataset with each quarterly recession series and the imputed quarterly values for the first and second recessions is usgdp_pk_2020-07-01.csv.

Functionality of the dynamic visualization

This dynamic visualization allows the user to customize some different views and manipulations of the data using the following functionalities.

Contributing to this visualization code

This dynamic visualization was created using the scripts written in the Python programming language. I used the Bokeh plotting library to create the JavaScript for the visualization. All of the scripts, data, and detailed documentation are available on the GitHub page for this visualization (https://github.com/OpenSourceEcon/USgdp_NormPeakPlot). You can fork that repository and follow the instructions in the README.md to create and modify this visualization on your own machine. If you wish to improve or enhance this code or if you find errors or bugs, please consider the following ways to contribute to this project.


References

Evans, Richard W., “Code for creating normalized peak plot of U.S. real GDP (GDPC1) in last 15 recessions,” https://github.com/OpenSourceEcon/USgdp_NormPeakPlot, (October 29, 2020).