<p>In general, real output is  calculated like this:
$$RGDP_{t, b} = NGDP_t \cdot p_{base} / p_t$$
Where $NGDP_t$ is nominal GDP at time t, $p_t$ is the price level in time $t$ and $p_{base}$ is the price level in the base period.</p>

<p>To covert RGDP between base periods, note that the ratio to a common year's $RGDP_t$ in two different base years is:
$$RGDP_{t, b1} / RGDP_{t, b2}  =  p_{base1} /  p_{base2}$$</p>

<p>You can rearrange this equality to solve for what you want:
$$RGDP_{t, b2}  =RGDP_{t, b1} \cdot p_{base1} /  p_{base2}$$</p>

CC BY-SA 3.0
2015-05-10T13:16:12.570Z
2015-05-10T15:12:30.807Z
2015-05-10T15:12:30.807Z
BKay
<p><em><a href="http://orff.uc3m.es/handle/10016/5334" rel="nofollow">Estimating regional Gdp in Italy (1871-2001): 
sources, methodology, and results</a> (Felice, E)</em></p>

<p>This article has Italian historical regional GDP figures, but they are in constant 2001 euros not in 1990 Geary–Khamis dollars where I can compare them more easily with other GDP figures. Would someone show me how you go about converting 2001 euros to 1990 Geary–Khamis dollars?   </p>

<inflation><gdp><exchange-rates><base-year>
Changing the base year of Real GDP from 2001 Euros to 1990 Geary–Khamis dollars
bdanger
# Changing the base year of Real GDP from 2001 Euros to 1990 Geary–Khamis dollars

(Asked by: username_0 on 2015-05-10)

*[Estimating regional Gdp in Italy (1871-2001):
sources, methodology, and results](http://orff.uc3m.es/handle/10016/5334) (Felice, E)*

This article has Italian historical regional GDP figures, but they are in constant 2001 euros not in 1990 Geary–Khamis dollars where I can compare them more easily with other GDP figures. Would someone show me how you go about converting 2001 euros to 1990 Geary–Khamis dollars?

**Tags:** inflation, gdp, exchange-rates, base-year


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## 1 answers

### Answer by username_1 on 2015-05-10. Score: 3

In general, real output is calculated like this:
$$RGDP\_{t, b} = NGDP\_t \cdot p\_{base} / p\_t$$
Where $NGDP\_t$ is nominal GDP at time t, $p\_t$ is the price level in time $t$ and $p\_{base}$ is the price level in the base period.

To covert RGDP between base periods, note that the ratio to a common year's $RGDP\_t$ in two different base years is:
$$RGDP\_{t, b1} / RGDP\_{t, b2} = p\_{base1} / p\_{base2}$$

You can rearrange this equality to solve for what you want:
$$RGDP\_{t, b2} =RGDP\_{t, b1} \cdot p\_{base1} / p\_{base2}$$


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