<p>Good question! </p>

<p>I've never seen standard errors reported alongside official figures (e.g. <a href="https://www.bea.gov/newsreleases/national/gdp/gdpnewsrelease.htm" rel="nofollow noreferrer">here</a> for US, <a href="https://www.ons.gov.uk/economy/grossdomesticproductgdp/bulletins/quarterlynationalaccounts/jantomar2017" rel="nofollow noreferrer">here</a> for UK). You would expect they could calculate/report them, since GDP is computed from samples (so randomness is explicitly involved in the design). It is more common to see standard errors reported for GDP forecasts though. For example, check Figure 2.1 of the latest <a href="http://www.bankofengland.co.uk/publications/Documents/inflationreport/2017/may.pdf" rel="nofollow noreferrer">Bank of England Inflation report</a> (data <a href="http://www.bankofengland.co.uk/publications/Documents/inflationreport/2017/may2.xlsx" rel="nofollow noreferrer">here</a>). </p>

<p>Regarding GDP, what is very common however is the publication of <strong>revised figures</strong>. That is something both the US and UK include in their quarterly reports (see links above), and also common in many (in not all) countries. Comparing actual and revised figures gives you an idea of the uncertainty involved on preliminary estimates. For example, in the release notes for quarterly GDP of the US economy (see link above), towards the end there is a section called "Updates to GDP", which contains:</p>

<blockquote>
  <p>BEA releases three vintages of the current quarterly estimate for GDP:  "Advance" estimates are
  released near the end of the first month following the end of the quarter and are based on source data
  that are incomplete or subject to further revision by the source agency; “second” and “third” estimates
  are released near the end of the second and third months, respectively, and are based on more detailed
  and more comprehensive data as they become available. [...]</p>
  
  <p>The table below shows the average revisions to the quarterly percent changes in real GDP between
  different estimate vintages, without regard to sign.</p>
  
  <p><a href="https://i.sstatic.net/7mGgE.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/7mGgE.png" alt="enter image description here"></a></p>
</blockquote>

<p>The Bank of England also provides its estimates of the past uncertainty (what they call "backcast", in opposition to "forecast"). This is available in the last sheet of <a href="http://www.bankofengland.co.uk/publications/Documents/inflationreport/2017/may2.xlsx" rel="nofollow noreferrer">this dataset</a>.</p>

<p>Another interesting example comes from the Euro Area. Eurostat produces quarterly "<a href="http://ec.europa.eu/eurostat/statistics-explained/index.php/Preliminary_GDP_flash_estimate_in_30_days_for_Europe" rel="nofollow noreferrer">Preliminary GDP flash estimates</a>" for the Euro Area for selection of periods: 30, 45, and 60 days after the end of the quarter. As the page states, there is "a trade-off between timeliness and accuracy". An example of subsequent revisions are:</p>

<p><a href="https://i.sstatic.net/dHopD.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/dHopD.png" alt="enter image description here"></a></p>

CC BY-SA 3.0
2017-08-24T06:57:09.433Z
2017-08-24T07:11:27.143Z
2017-08-24T07:11:27.143Z
luchonacho
<p>The government and media seem to judge whether it is in a good economy right now based on its quarterly GDP figure.</p>

<p>However, I wonder how its figure is trustworthy. Even if the quarterly GDP is +1.2%, the actual figure should be +0.3 to +1.9% in 95% CI. Or -0.8% to 3.0%. Or something like that. But the point is that it should never be at the exact point, especially given that the figure is frequently updated later.</p>

<p>So how much standard error is it considered to include?</p>

CC BY-SA 3.0
2017-10-23T07:31:03.780Z
For which country? Which decade? After which revision?
410 gone
CC BY-SA 3.0
2017-10-24T07:02:57.930Z
You can also take a look at this question to clarify a bit your point: https://economics.stackexchange.com/questions/12311/how-to-measure-gdp-in-practice/17812#17812
JoaoBotelho
<gdp><statistics>
What is the standard error on quarterly GDP figure?
Blaszard
# What is the standard error on quarterly GDP figure?

(Asked by: username_0 on 2017-08-24)

The government and media seem to judge whether it is in a good economy right now based on its quarterly GDP figure.

However, I wonder how its figure is trustworthy. Even if the quarterly GDP is +1.2%, the actual figure should be +0.3 to +1.9% in 95% CI. Or -0.8% to 3.0%. Or something like that. But the point is that it should never be at the exact point, especially given that the figure is frequently updated later.

So how much standard error is it considered to include?

**Tags:** gdp, statistics
> **Comments:**
> **username_1**: For which country? Which decade? After which revision?  
> **username_2**: You can also take a look at this question to clarify a bit your point: https://economics.stackexchange.com/questions/12311/how-to-measure-gdp-in-practice/17812#17812  

---

## 1 answers

### Answer by username_3 on 2017-08-24. Score: 1

Good question!

I've never seen standard errors reported alongside official figures (e.g. [here](https://www.bea.gov/newsreleases/national/gdp/gdpnewsrelease.htm) for US, [here](https://www.ons.gov.uk/economy/grossdomesticproductgdp/bulletins/quarterlynationalaccounts/jantomar2017) for UK). You would expect they could calculate/report them, since GDP is computed from samples (so randomness is explicitly involved in the design). It is more common to see standard errors reported for GDP forecasts though. For example, check Figure 2.1 of the latest [Bank of England Inflation report](http://www.bankofengland.co.uk/publications/Documents/inflationreport/2017/may.pdf) (data [here](http://www.bankofengland.co.uk/publications/Documents/inflationreport/2017/may2.xlsx)).

Regarding GDP, what is very common however is the publication of **revised figures**. That is something both the US and UK include in their quarterly reports (see links above), and also common in many (in not all) countries. Comparing actual and revised figures gives you an idea of the uncertainty involved on preliminary estimates. For example, in the release notes for quarterly GDP of the US economy (see link above), towards the end there is a section called "Updates to GDP", which contains:

> BEA releases three vintages of the current quarterly estimate for GDP: "Advance" estimates are
> released near the end of the first month following the end of the quarter and are based on source data
> that are incomplete or subject to further revision by the source agency; “second” and “third” estimates
> are released near the end of the second and third months, respectively, and are based on more detailed
> and more comprehensive data as they become available. [...]
>
> The table below shows the average revisions to the quarterly percent changes in real GDP between
> different estimate vintages, without regard to sign.
>
> [![enter image description here](https://i.sstatic.net/7mGgE.png)](https://i.sstatic.net/7mGgE.png)

The Bank of England also provides its estimates of the past uncertainty (what they call "backcast", in opposition to "forecast"). This is available in the last sheet of [this dataset](http://www.bankofengland.co.uk/publications/Documents/inflationreport/2017/may2.xlsx).

Another interesting example comes from the Euro Area. Eurostat produces quarterly "[Preliminary GDP flash estimates](http://ec.europa.eu/eurostat/statistics-explained/index.php/Preliminary_GDP_flash_estimate_in_30_days_for_Europe)" for the Euro Area for selection of periods: 30, 45, and 60 days after the end of the quarter. As the page states, there is "a trade-off between timeliness and accuracy". An example of subsequent revisions are:

[![enter image description here](https://i.sstatic.net/dHopD.png)](https://i.sstatic.net/dHopD.png)


---

