<p>I'm looking at the <a href="https://www.rug.nl/ggdc/docs/pwt90.dta" rel="nofollow noreferrer">Penn World Table 9.0 data</a>, and find that the "Share of merchandise imports at current PPPs" (<code>csh_m</code>) can be negative. For example,</p>

<pre><code>   country  year  csh_m
   &lt;chr&gt;   &lt;dbl&gt;  &lt;dbl&gt;
 1 Aruba   1970. -0.485
 2 Aruba   1971. -0.459
 3 Aruba   1972. -0.436
 4 Aruba   1973. -0.441
</code></pre>

<p>My initial thought is that the share of import (<code>csh_m</code>) here actually means "net import as share of GDP." However, this is not correct, because share of import (<code>csh_m</code>) and share of export (<code>csh_x</code>) don't have the same magnitude.</p>

<pre><code>   country  year  csh_m csh_x
   &lt;chr&gt;   &lt;dbl&gt;  &lt;dbl&gt; &lt;dbl&gt;
 1 Aruba   1970. -0.485 0.427
 2 Aruba   1971. -0.459 0.435
 3 Aruba   1972. -0.436 0.441
 4 Aruba   1973. -0.441 0.477
</code></pre>

<ol>
<li><p>Where can I find documentation explaining the construction of <code>csh_m</code> and <code>csh_x</code> from the Penn World Table?</p></li>
<li><p>If a want to construct a variable of trade openness, should I add the absolute values of <code>csh_m</code> and <code>csh_x</code>?</p></li>
</ol>

CC BY-SA 3.0
2018-03-15T17:39:53.600Z
Have you looked at p3 of http://www.rug.nl/ggdc/docs/national_accounts_in_pwt80.pdf ?  If it's only very small countries, could it be that statistical discrepancies are larger than imports?
Dan
CC BY-SA 4.0
2019-08-05T22:28:50.960Z
All the `csh_m` (Share of merchandise imports at current PPPs) numbers in that table for all years and all countries are negative  (apart from some years for Bermuda) while all `csh_x` (Share of merchandise exports at current PPPs) are positive (again except for a few years for Bermuda).  These shares look like $Y=C+I+G+X-M+R$ all divided by $Y$. Places with big absolute values seem to include Hong Kong, Singapore, BVI, Malta, Turks & Caicos, where trade is indeed open.  So you could add the absolute numbers together
Henry
CC BY-SA 4.0
2019-08-05T22:30:14.707Z
See https://www.rug.nl/ggdc/productivity/pwt/ and the legend tab of the Excel spreadsheet for more explanation about the data
Henry
<macroeconomics><gdp><international-trade>
How can the "Share of merchandise imports at current PPPs" be negative?
Heisenberg
# How can the "Share of merchandise imports at current PPPs" be negative?

(Asked by: username_0 on 2018-03-14)

I'm looking at the Penn World Table 9.0 data, and find that the "Share of merchandise imports at current PPPs" (csh_m) can be negative. For example,
   country  year  csh_m
        
 1 Aruba   1970. -0.485
 2 Aruba   1971. -0.459
 3 Aruba   1972. -0.436
 4 Aruba   1973. -0.441

My initial thought is that the share of import (csh_m) here actually means "net import as share of GDP." However, this is not correct, because share of import (csh_m) and share of export (csh_x) don't have the same magnitude.
   country  year  csh_m csh_x
         
 1 Aruba   1970. -0.485 0.427
 2 Aruba   1971. -0.459 0.435
 3 Aruba   1972. -0.436 0.441
 4 Aruba   1973. -0.441 0.477


Where can I find documentation explaining the construction of csh_m and csh_x from the Penn World Table?
If a want to construct a variable of trade openness, should I add the absolute values of csh_m and csh_x?

**Tags:** macroeconomics, gdp, international-trade
> **Comments:**
> **username_1**: Have you looked at p3 of http://www.rug.nl/ggdc/docs/national_accounts_in_pwt80.pdf ?  If it's only very small countries, could it be that statistical discrepancies are larger than imports?  
> **username_2**: All the `csh_m` (Share of merchandise imports at current PPPs) numbers in that table for all years and all countries are negative  (apart from some years for Bermuda) while all `csh_x` (Share of merchandise exports at current PPPs) are positive (again except for a few years for Bermuda).  These shares look like $Y=C+I+G+X-M+R$ all divided by $Y$. Places with big absolute values seem to include Hong Kong, Singapore, BVI, Malta, Turks & Caicos, where trade is indeed open.  So you could add the absolute numbers together  
> **username_2**: See https://www.rug.nl/ggdc/productivity/pwt/ and the legend tab of the Excel spreadsheet for more explanation about the data  

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## 0 answers

