<p>I like this explanation from <a href="http://www.imf.org/external/pubs/ft/fandd/2007/03/basics.htm" rel="nofollow noreferrer">Callen (2007)</a>, published in the IMF's F&amp;D, their quarterly magazine.  For measuring consumption in a country, PPP is probably the way to go, but international economic and financial power is probably better measured with market rates.</p>
<blockquote>
<p><strong>PPP versus market rates</strong></p>
<p>So which method is better? The appropriate way to aggregate economic
data across countries depends on the issue being considered. Market
exchange rates are the logical choice when financial flows are
involved. For example, the current account balance represents a flow
of financial resources across countries. It is appropriate to use the
market exchange rate to convert these flows into dollars when
aggregating across regions or calculating the global current account
discrepancy. But for other variables, the decision is less clear cut.
Take real GDP growth. International organizations use different
approaches. The World Bank uses market-based rates to determine the
weights in its regional and global aggregations of real GDP, whereas
the IMF and the Organization for Economic Cooperation and Development
use weights based on PPP rates (although the IMF also publishes a
global growth aggregate based on market rates in the WEO). Each
methodology has its advantages and disadvantages.</p>
<p><strong>Advantages of PPP</strong><br />
A main one is that PPP exchange rates are relatively stable over time. By contrast, market rates are more
volatile, and using them could produce quite large swings in aggregate
measures of growth even when growth rates in individual countries are
stable. Another drawback of market-based rates is that they are
relevant only for internationally traded goods. Nontraded goods and
services tend to be cheaper in low-income than in high-income
countries. A haircut in New York is more expensive than in Lima; the
price of a taxi ride of the same distance is higher in Paris than in
Tunis; and a ticket to a cricket game costs more in London than in
Lahore. Indeed, because wages tend to be lower in poorer countries,
and services are often relatively labor intensive, the price of a
haircut in Lima is likely to be cheaper than in New York even when the
cost of making tradable goods, such as machinery, is the same in both
countries. Any analysis that fails to take into account these
differences in the prices of nontraded goods across countries will
underestimate the purchasing power of consumers in emerging market and
developing countries and, consequently, their overall welfare. For
this reason, PPP is generally regarded as a better measure of overall
well-being.</p>
<p><strong>Drawbacks of PPP</strong></p>
<p>The biggest one is that PPP is harder to measure than market-based rates. The ICP is a huge statistical undertaking,
and new price comparisons are available only at infrequent intervals.
Methodological questions have also been raised about earlier surveys.
In between survey dates, the PPP rates have to be estimated, which can
introduce inaccuracies into the measurement. Also, the ICP does not
cover all countries, which means that data for missing countries have
to be estimated.</p>
</blockquote>

CC BY-SA 4.0
2018-08-20T19:22:14.600Z
Thanks. So would you say the GDP at PPP quantifies the value (or _level_) of a country's material well-being (as proxied by consumption)?
StatsScared
CC BY-SA 4.0
2018-08-15T22:46:32.610Z
2018-08-15T22:46:32.610Z
2020-06-17T09:40:54.643Z
BKay
<p>I understand the implications of having a higher/lower GDP at market exchange rates. I also understand what PPP measures. </p>

<p>But, what does a difference in GDP, at PPP, indicate in terms of differences in <em>levels</em>?</p>

<macroeconomics><purchasing-power-partity>
What does it mean if country X has a higher GDP at Purchasing Power Parity (PPP) than country Y?
StatsScared
# What does it mean if country X has a higher GDP at Purchasing Power Parity (PPP) than country Y?

(Asked by: username_0 on 2018-08-15)

I understand the implications of having a higher/lower GDP at market exchange rates. I also understand what PPP measures.

But, what does a difference in GDP, at PPP, indicate in terms of differences in *levels*?

**Tags:** macroeconomics, purchasing-power-partity


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## 1 answers

### Answer by username_1 on 2018-08-15. Score: 1

I like this explanation from [Callen (2007)](http://www.imf.org/external/pubs/ft/fandd/2007/03/basics.htm), published in the IMF's F&D, their quarterly magazine. For measuring consumption in a country, PPP is probably the way to go, but international economic and financial power is probably better measured with market rates.

> **PPP versus market rates**
>
> So which method is better? The appropriate way to aggregate economic
> data across countries depends on the issue being considered. Market
> exchange rates are the logical choice when financial flows are
> involved. For example, the current account balance represents a flow
> of financial resources across countries. It is appropriate to use the
> market exchange rate to convert these flows into dollars when
> aggregating across regions or calculating the global current account
> discrepancy. But for other variables, the decision is less clear cut.
> Take real GDP growth. International organizations use different
> approaches. The World Bank uses market-based rates to determine the
> weights in its regional and global aggregations of real GDP, whereas
> the IMF and the Organization for Economic Cooperation and Development
> use weights based on PPP rates (although the IMF also publishes a
> global growth aggregate based on market rates in the WEO). Each
> methodology has its advantages and disadvantages.
>
> **Advantages of PPP**  
> A main one is that PPP exchange rates are relatively stable over time. By contrast, market rates are more
> volatile, and using them could produce quite large swings in aggregate
> measures of growth even when growth rates in individual countries are
> stable. Another drawback of market-based rates is that they are
> relevant only for internationally traded goods. Nontraded goods and
> services tend to be cheaper in low-income than in high-income
> countries. A haircut in New York is more expensive than in Lima; the
> price of a taxi ride of the same distance is higher in Paris than in
> Tunis; and a ticket to a cricket game costs more in London than in
> Lahore. Indeed, because wages tend to be lower in poorer countries,
> and services are often relatively labor intensive, the price of a
> haircut in Lima is likely to be cheaper than in New York even when the
> cost of making tradable goods, such as machinery, is the same in both
> countries. Any analysis that fails to take into account these
> differences in the prices of nontraded goods across countries will
> underestimate the purchasing power of consumers in emerging market and
> developing countries and, consequently, their overall welfare. For
> this reason, PPP is generally regarded as a better measure of overall
> well-being.
>
> **Drawbacks of PPP**
>
> The biggest one is that PPP is harder to measure than market-based rates. The ICP is a huge statistical undertaking,
> and new price comparisons are available only at infrequent intervals.
> Methodological questions have also been raised about earlier surveys.
> In between survey dates, the PPP rates have to be estimated, which can
> introduce inaccuracies into the measurement. Also, the ICP does not
> cover all countries, which means that data for missing countries have
> to be estimated.

> **Comments:**
> **username_0**: Thanks. So would you say the GDP at PPP quantifies the value (or _level_) of a country's material well-being (as proxied by consumption)?  

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