<p>I usually take the 4th difference for annualized quarterly data.</p>
<pre><code>x2 &lt;- diff(log(x1), lag=4) * 100 
</code></pre>
<p>Indeed, you need to see the difference with the same quarter the past year, thus 4 periods before !</p>
<p>With your data, you would have</p>
<pre><code>annualized_gdp = diff(log(rgdp), 4)*100
</code></pre>
<p>and it should give the good series ! In addition, it should withdraw any saisonnality in your data</p>

CC BY-SA 4.0
2023-12-03T11:26:13.793Z
2023-12-03T11:26:13.793Z
justaneconomist
<p>Perhaps quarterly growth should be multiplied by 400, but not <em>annualized</em> quarterly growth?</p>

CC BY-SA 4.0
2021-04-11T19:11:16.970Z
is this not more appropriately a comment than an answer?
Jesper Hybel
CC BY-SA 4.0
2021-04-11T19:37:21.000Z
@JesperHybel I felt like this answered the question in full, but if you disagree you can raise a flag to have this converted into a comment. And of course you are encouraged to post a better answer.
Giskard
CC BY-SA 4.0
2021-04-12T01:07:45.640Z
I dont really know so I dont disagree. I was just reacting to the use of »perhaps« and »?« thinking you perhaps misposted.
Jesper Hybel
CC BY-SA 4.0
2018-11-23T14:45:20.283Z
2018-11-23T14:45:20.283Z
Giskard
<p>I was using R to calculate the annualized quarterly growth rate of real GDP by 400*diff(log(rgdp)).</p>

<p>If I perform in this way some of the percentage change is big.</p>

<p>However, if I calculate as 100*diff(log(rgdp)) than results seems to be accurate as what shows up on the most of the website.</p>

<p>Why is this happening? follow by the growth formula it should be multiplied by 400, not 100.</p>

CC BY-SA 4.0
2019-04-22T17:25:03.910Z
Is the data you have in GDP annual or quarterly? if it is annual, then the 100 is appropriate.
Regio
<economic-growth>
annualized quarterly growth rate calculating
user20269
# annualized quarterly growth rate calculating

(Asked by: username_0 on 2018-11-23)

I was using R to calculate the annualized quarterly growth rate of real GDP by 400\*diff(log(rgdp)).

If I perform in this way some of the percentage change is big.

However, if I calculate as 100\*diff(log(rgdp)) than results seems to be accurate as what shows up on the most of the website.

Why is this happening? follow by the growth formula it should be multiplied by 400, not 100.

**Tags:** economic-growth

> **Comments:**
> **username_1**: Is the data you have in GDP annual or quarterly? if it is annual, then the 100 is appropriate.  

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## 2 answers

### Answer by username_2 on 2023-12-03. Score: 1

I usually take the 4th difference for annualized quarterly data.
x2 <- diff(log(x1), lag=4) * 100 

Indeed, you need to see the difference with the same quarter the past year, thus 4 periods before !
With your data, you would have
annualized_gdp = diff(log(rgdp), 4)*100

and it should give the good series ! In addition, it should withdraw any saisonnality in your data


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### Answer by username_3 on 2018-11-23. Score: 1

Perhaps quarterly growth should be multiplied by 400, but not *annualized* quarterly growth?

> **Comments:**
> **username_4**: is this not more appropriately a comment than an answer?  
> **username_3**: @JesperHybel I felt like this answered the question in full, but if you disagree you can raise a flag to have this converted into a comment. And of course you are encouraged to post a better answer.  
> **username_4**: I dont really know so I dont disagree. I was just reacting to the use of »perhaps« and »?« thinking you perhaps misposted.  

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