The graph below is based on estimates of global GDP over time from The World Bank (in the period 1960-2021) and from DeLong, 1998 (prior to 1960). The graph draws a smoothed-out line between the estimated growth rate at the respective years listed along the x-axis, between which the world economy has seen a full doubling.
Is the value for 2021 the annual growth rate from 2020 to 2021, or the annual growth rate from 1997 to 2021 (i.e. growth during the prior doubling)? The above suggests the former, but I think you meant the latter.
It’s indeed not obvious what I mean when I write “a smoothed-out line between the estimated growth rate at the respective years listed along the x-axis”. It’s neither the annual growth rate in that particular year in isolation (which is subject to significant fluctuations), nor the annual average growth rate from the previously listed year to the next listed year (which would generally not be a good estimate for the latter year).
Instead, it’s an estimated underlying growth rate at that year based on the growth rates in the (more) closely adjacent years. I can see that the value I estimated for 2021 was 2.65 percent, the average growth rate from 2015-2022 (according to the data from The World Bank). One could also have chosen, say, 2020-2022, which would yield an estimate of 2.01 percent, but that’s arguably too low an estimate given the corona recession.
Great analysis, Magnus!
Is the value for 2021 the annual growth rate from 2020 to 2021, or the annual growth rate from 1997 to 2021 (i.e. growth during the prior doubling)? The above suggests the former, but I think you meant the latter.
Thanks, and thanks for the question! :)
It’s indeed not obvious what I mean when I write “a smoothed-out line between the estimated growth rate at the respective years listed along the x-axis”. It’s neither the annual growth rate in that particular year in isolation (which is subject to significant fluctuations), nor the annual average growth rate from the previously listed year to the next listed year (which would generally not be a good estimate for the latter year).
Instead, it’s an estimated underlying growth rate at that year based on the growth rates in the (more) closely adjacent years. I can see that the value I estimated for 2021 was 2.65 percent, the average growth rate from 2015-2022 (according to the data from The World Bank). One could also have chosen, say, 2020-2022, which would yield an estimate of 2.01 percent, but that’s arguably too low an estimate given the corona recession.
Thanks for clarifying!