Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>It seems you only want to compare consecutive years (by firm) which can be done like this:</p> <pre><code>clear all set more off input firm_id year total_workers 1 1975 614 1 1976 68 1 1977 708 1 1978 18 1 1979 536 3 1975 154 3 1976 59 3 1977 115 3 1978 40 3 1979 380 4 1975 49 4 1976 42 4 1977 53 4 1978 54 4 1979 34 5 1975 254 5 1976 1115 end sort firm_id year // important list, sepby(firm_id) by firm_id: gen flag = (total_workers[_n] &gt; 10*total_workers[_n-1]) list if flag == 1 </code></pre> <p>The important points are the <code>sort</code> and the use of <a href="http://www.stata.com/help.cgi?subscripting" rel="nofollow">subscripting</a>.</p> <p>To make it one line shorter, you can incorporate the <code>sort</code> into the main instruction like this:</p> <pre><code>bysort firm_id (year): gen flag = (total_workers[_n] &gt; 10*total_workers[_n-1]) </code></pre> <p>The reason your code doesn't work is that Stata evaluates it on the dataset line by line (i.e. observation by observation from top to bottom) - I appreciate any correction if there's an error here -. You are asking Stata to tabulate only if one observed instance of the variable is larger than itself multiplied by 10 which is impossible (i.e. always false). See the output of the following:</p> <pre><code>bysort firm_id (year): gen flag = 1 if total_workers &gt; 10*total_workers </code></pre> <p>Using subscripts explicitly, the previous line is equivalent to</p> <pre><code>bysort firm_id (year): gen flag = 1 if total_workers[_n] &gt; 10*total_workers[_n] </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POif condition depending on existence
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USRoberto Ferrer
    1. USRoberto Ferrer
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POif condition depending on existence
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThank you very much for your answer! This is what I wanted. How do I have to change the code if I also want to cover the case when **total_workers[_n-1] > 10*total_workers[_n]**?
      singulars
      1. PO
      1. USthe_economist
    2. COYou're welcome. You can be even more explicit and describe "exactly" what you seek. This can take more time in terms of posting/editing your question, but in the long-run, it is more efficient for everyone.
      singulars
      1. PO
      1. USRoberto Ferrer
    3. COI'm sorry for having been vague.
      singulars
      1. PO
      1. USthe_economist
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload