title: Show Akaike Criteria in Stargazer
body: <p>I have two linear models created with <code>lm</code> that I would like to compare with a table in the <code>stargazer</code> package. For the most part, I like the results I'm getting. But the Akaike Information Criterion is not showing. <a href="https://cran.r-project.org/web/packages/stargazer/stargazer.pdf" rel="noreferrer">The docs</a> say I can pass <code>"aic"</code> in the <code>keep.stat</code> argument to include it. But it's not there. No error messages.</p>
  
  <pre><code>stargazer(model1, model2, type="text", report="vc", header=FALSE,
            title="Linear Models Predicting Forest Land",
            keep.stat=c("aic", "rsq", "n"), omit.table.layout="n")
  
  Linear Models Predicting Forest Land
  ==========================================
                        Dependent variable: 
                        --------------------
                               forest       
                           (1)        (2)   
  ------------------------------------------
  log.MS.MIL.XPND.GD.ZS  -11.948    -12.557 
  
  log.TX.VAL.AGRI.ZS.UN   2.310      2.299  
  
  log.NY.GDP.MKTP.CD                 0.505  
  
  Constant                40.857    28.365  
  
  ------------------------------------------
  Observations             183        183   
  R2                      0.142      0.146  
  ==========================================
  </code></pre>
  
  <p>I don't see any reason why it wouldn't be able to include it. Calling the global <code>AIC</code> function on these models works fine.</p>
  
  <pre><code>&gt; AIC(model1)
  [1] 1586.17
  &gt; AIC(model2)
  [1] 1587.208
  </code></pre>