title: Panel data fixed effect issue with R, I don't see my all dummy variables in the summary
body: <p>I'm running a data panel regression with R.
  I use those <a href="https://docs.google.com/spreadsheets/d/1fXzrKS0ABn-ygKWnGhKskmoCLNikZCsY_u1yu08uSq4/edit?usp=sharing" rel="nofollow noreferrer">data</a>(sheet 2).</p>
  
  <p>I want to use a fixed effect for my panel data. Please, find below the code for my fixed effect</p>
  
  <pre><code>FE_1 &lt;- plm(GDP_per_capita_growth ~ 
             log(GDP_per_capita) + GF_GDP + MA_GDP + 
             start_business + Invest_GDP +
             second_schooling + Pop_growth + 
             log(Inflation_CPI) + Trade + 
             GF_GDP * start_business +
             factor(as.character(time_fixed_effect)) + 
             factor(as.character(regional)) +
             factor(as.character(oil_exporting_countries)),
             data = Temp_1,
             index = c("country",
                       "year"),
             na.action = na.omit,
             model = "within") 
  </code></pre>
  
  <p>When I run the summary for my panel data fixed effect, some variables are missing, such as time_fixed_effect, regional and oil_exporting_countries.
  Below, the result I got.</p>
  
  <pre><code>Coefficients:
                                              Estimate  Std. Error t-value  Pr(&gt;|t|)    
  log(GDP_per_capita)                      -1.9676e+01  5.0218e+00 -3.9181 0.0001386 ***
  GF_GDP                                    1.2637e+00  1.9705e+00  0.6413 0.5223695    
  MA_GDP                                    1.9337e+01  8.3736e+00  2.3093 0.0223807 *  
  start_business                           -1.3378e-07  1.0077e-07 -1.3276 0.1864403    
  Invest_GDP                                1.5166e-08  1.1173e-08  1.3574 0.1768341    
  second_schooling                         -4.9808e-01  5.4186e+00 -0.0919 0.9268910    
  Pop_growth                               -1.6174e+00  5.9779e-01 -2.7055 0.0076606 ** 
  log(Inflation_CPI)                        1.3861e-01  3.2403e-01  0.4278 0.6694806    
  Trade                                     1.8669e-02  1.8617e-02  1.0028 0.3176852    
  factor(as.character(time_fixed_effect))1  3.8295e-01  4.4318e-01  0.8641 0.3890017    
  GF_GDP:start_business                     5.0494e-07  3.4416e-07  1.4672 0.1445566    
  ---
  </code></pre>
  
  <p>I would like to know, what should I need to do to display all my dummy variables. Is there an error somewhere in my code?</p>
  
  <p>Instead of having <code>index = c("country", "year"),</code>, I wrote <code>index = c("year", "country"),</code>, and I got this following result: </p>
  
  <pre><code>Coefficients:
                                                    Estimate  Std. Error t-value Pr(&gt;|t|)   
  log(GDP_per_capita)                            -3.3627e+00  2.0642e+00 -1.6291 0.105013   
  GF_GDP                                          1.2334e+00  1.8129e+00  0.6804 0.497127   
  MA_GDP                                          5.2312e-01  6.4419e+00  0.0812 0.935366   
  start_business                                  1.4314e-08  3.0105e-08  0.4755 0.635022   
  Invest_GDP                                     -9.8744e-10  1.5174e-09 -0.6507 0.516025   
  second_schooling                                1.0860e+00  1.0806e+00  1.0050 0.316205   
  Pop_growth                                     -6.3753e-01  2.2690e-01 -2.8097 0.005494 **
  log(Inflation_CPI)                              1.4547e-01  2.5011e-01  0.5816 0.561550   
  Trade                                           9.2730e-04  3.8306e-03  0.2421 0.808991   
  factor(as.character(regional))2                -1.0668e+00  8.3584e-01 -1.2763 0.203441   
  factor(as.character(regional))3                -2.6186e-01  6.6220e-01 -0.3954 0.692972   
  factor(as.character(regional))4                 1.4760e-01  7.9347e-01  0.1860 0.852639   
  factor(as.character(regional))5                 1.3558e+00  7.2400e-01  1.8727 0.062696 . 
  factor(as.character(oil_exporting_countries))1 -1.8890e-01  4.4884e-01 -0.4209 0.674344   
  GF_GDP:start_business                          -2.9751e-08  1.3526e-07 -0.2199 0.826157   
  ---
  </code></pre>
  
  <p>I don't know why I got this result! Can you help me to find out why, please? And also help me to display my "time_fixed-effect" variable, please.</p>
  
  <p>Thank you in advance for your precious help.</p>
  
  <p>PS: This is complete code</p>
  
  <pre><code># Rename column names
  colnames(my_data)[4] &lt;- "Invest_GDP" # percentage
  colnames(my_data)[9] &lt;- "Pr_sector_GDP" # percentage
  colnames(my_data)[12] &lt;- "start_business"
  colnames(my_data)[16] &lt;- "second_schooling"
  colnames(my_data)[18] &lt;- "GDP_per_capita_growth"
  
  # Transform column "inflation" as numeric
  my_data$Inflation_CPI &lt;- as.numeric(my_data$Inflation_CPI)
  my_data$second_schooling &lt;- as.numeric(my_data$second_schooling)
  
  Temp_1 &lt;-  my_data %&gt;%
    select( 
           -region, 
           -Pr_sector_GDP,
           -Prop_rights,
           -T_freedom,
           -current_invest
    )
  </code></pre>