# st: F-statistics missing from simple OLS regression with robust s.e.

 From "Ngo,PT (pgr)" To Subject st: F-statistics missing from simple OLS regression with robust s.e. Date Mon, 23 Aug 2004 11:41:45 +0100

```Dear Statalisters,

This is a very basic question and may be the answer is blindingly obvious!

I am running simple OLS regression with dummies for communes, to control for unobserved characteristics that may make some of my variables endogenous.

xi: reg riyielA2 primary counting ianulandsha2 anugood2  anubad2 i.fsize extenworker2  marketdis2 roadimpassmonth2  electmost2 i.comm92, rob

However, the F statistics is missing. There are 2832 observation and 120 communes.

Would someone have an idea as to why this is the case? I paste the output below.

I wish you all a very nice (and productive) summer.

Thi Minh

. xi: reg riyielA2 primary counting ianulandsha2 anugood2  anubad2 i.fsize extenworker2  marketdis2 roadimpa
> ssmonth2  electmost2 i.comm92 if north==0, rob
i.fsize           _Ifsize_1-7         (naturally coded; _Ifsize_1 omitted)
i.comm92          _Icomm92a1-150      (naturally coded; _Icomm92a1 omitted)

Regression with robust standard errors                 Number of obs =    1060
F( 59,   999) =       .
Prob > F      =       .
R-squared     =  0.3650
Root MSE      =  1.1907

------------------------------------------------------------------------------
|               Robust
riyielA2 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
primary2 |    .238943   .0814221     2.93   0.003      .079165    .3987211
counting8 |   .1574271   .0824014     1.91   0.056    -.0042727    .3191268
ianulandsha2 |  -.1169965   .1206858    -0.97   0.333    -.3538232    .1198302
anugood2 |    .517437   .1500027     3.45   0.001     .2230805    .8117935
anubad2 |  -.2888542   .1266844    -2.28   0.023    -.5374523   -.0402562
_Ifsize_2 |   .0892729   .1100055     0.81   0.417    -.1265954    .3051413
_Ifsize_3 |   .0219927   .1371509     0.16   0.873    -.2471441    .2911295
_Ifsize_5 |   .1902934   .1482042     1.28   0.199    -.1005338    .4811207
_Ifsize_6 |   .1390849    .179857     0.77   0.440    -.2138559    .4920258
_Ifsize_7 |   .1529401   .2521221     0.61   0.544    -.3418095    .6476897
extenworker2 |  -1.281163   .2489915    -5.15   0.000    -1.769769   -.7925564
marketdis2 |  -.0484737   .0278609    -1.74   0.082    -.1031463    .0061989
roadimpass~2 |  -.0644231   .0211566    -3.05   0.002    -.1059395   -.0229066
electmost2 |  -.8403821   .2567902    -3.27   0.001    -1.344292   -.3364721
_Icomm92a2 |  (dropped)
_Icomm92a3 |  (dropped)
_Icomm92a4 |  (dropped)
_Icomm92a5 |  (dropped)
_Icomm92a6 |  (dropped)
_Icomm92a7 |  (dropped)
_Icomm92a8 |  (dropped)
_Icomm92a9 |  (dropped)
_Icomm92a10 |  (dropped)
_Icomm92a11 |  (dropped)
_Icomm92a12 |  (dropped)
_Icomm92a13 |  (dropped)
_Icomm92a14 |  (dropped)
_Icomm92a15 |  (dropped)
_Icomm92a16 |  (dropped)
_Icomm92a17 |  (dropped)
_Icomm92a18 |  (dropped)
_Icomm92a19 |  (dropped)
_Icomm92a20 |  (dropped)
_Icomm92a21 |  (dropped)
_Icomm92a22 |  (dropped)
_Icomm92a23 |  (dropped)
_Icomm92a24 |  (dropped)
_Icomm92a25 |  (dropped)
_Icomm92a26 |  (dropped)
_Icomm92a27 |  (dropped)
_Icomm92a28 |  (dropped)
_Icomm92a29 |  (dropped)
_Icomm92a30 |  (dropped)
_Icomm92a31 |  (dropped)
_Icomm92a32 |  (dropped)
_Icomm92a33 |  (dropped)
_Icomm92a34 |  (dropped)
_Icomm92a35 |  (dropped)
_Icomm92a36 |  (dropped)
_Icomm92a37 |  (dropped)
_Icomm92a38 |  (dropped)
_Icomm92a39 |  (dropped)
_Icomm92a40 |  (dropped)
_Icomm92a41 |  (dropped)
_Icomm92a42 |  (dropped)
_Icomm92a43 |  (dropped)
_Icomm92a44 |  (dropped)
_Icomm92a45 |  (dropped)
_Icomm92a46 |  (dropped)
_Icomm92a47 |  (dropped)
_Icomm92a48 |  (dropped)
_Icomm92a49 |  (dropped)
_Icomm92a50 |  (dropped)
_Icomm92a51 |  (dropped)
_Icomm92a52 |  (dropped)
_Icomm92a53 |  (dropped)
_Icomm92a54 |  (dropped)
_Icomm92a55 |  (dropped)
_Icomm92a56 |  (dropped)
_Icomm92a57 |  (dropped)
_Icomm92a58 |  (dropped)
_Icomm92a59 |  (dropped)
_Icomm92a60 |  (dropped)
_Icomm92a61 |  (dropped)
_Icomm92a62 |  (dropped)
_Icomm92a63 |  (dropped)
_Icomm92a64 |  (dropped)
_Icomm92a65 |  (dropped)
_Icomm92a66 |  (dropped)
_Icomm92a67 |  (dropped)
_Icomm92a68 |  (dropped)
_Icomm92a69 |  (dropped)
_Icomm92a70 |  -1.460631   .3615067    -4.04   0.000    -2.170031   -.7512314
_Icomm92a71 |   -.484527   .3498048    -1.39   0.166    -1.170963    .2019093
_Icomm92a72 |  -2.007965   .3601075    -5.58   0.000    -2.714619   -1.301312
_Icomm92a73 |  -1.497574   .3387886    -4.42   0.000    -2.162393   -.8327549
_Icomm92a74 |  -1.298576   .4921146    -2.64   0.008    -2.264273   -.3328793
_Icomm92a75 |  -.6078374   .3354461    -1.81   0.070    -1.266097    .0504223
_Icomm92a76 |  -1.328069    .297436    -4.47   0.000     -1.91174   -.7443978
_Icomm92a77 |  -2.324027   .3811031    -6.10   0.000    -3.071882   -1.576173
_Icomm92a78 |   .6342039   .3523299     1.80   0.072    -.0571876    1.325596
_Icomm92a79 |    .122647   .3098287     0.40   0.692    -.4853426    .7306366
_Icomm92a80 |  -1.826955    .502033    -3.64   0.000    -2.812115   -.8417947
_Icomm92a81 |    2.24553   .6112722     3.67   0.000     1.046006    3.445055
_Icomm92a82 |  -.3124623     .32691    -0.96   0.339    -.9539714    .3290468
_Icomm92a83 |  (dropped)
_Icomm92a84 |  -3.001611   .3966383    -7.57   0.000    -3.779951   -2.223272
_Icomm92a85 |   .6530298   .3644332     1.79   0.073    -.0621126    1.368172
_Icomm92a86 |   .9237367   1.173775     0.79   0.431     -1.37961    3.227084
_Icomm92a87 |  -2.307616   .3622094    -6.37   0.000    -3.018395   -1.596838
_Icomm92a88 |  -2.315165   .4097308    -5.65   0.000    -3.119197   -1.511134
_Icomm92a89 |  -.6401403   .5937521    -1.08   0.281    -1.805285     .525004
_Icomm92a90 |  -1.120234    .216255    -5.18   0.000      -1.5446   -.6958677
_Icomm92a91 |   1.148787   .3368922     3.41   0.001     .4876894    1.809884
_Icomm92a92 |  -2.681174   .3758231    -7.13   0.000    -3.418667   -1.943681
_Icomm92a93 |  -1.213704   .2861376    -4.24   0.000    -1.775204   -.6522045
_Icomm92a94 |  (dropped)
_Icomm92a95 |   -.402001   .4638297    -0.87   0.386    -1.312193    .5081912
_Icomm92a96 |  -1.396075   .3154201    -4.43   0.000    -2.015037   -.7771133
_Icomm92a97 |  -1.831305   .5208524    -3.52   0.000    -2.853396    -.809215
_Icomm92a98 |  -.8859774   .3371676    -2.63   0.009    -1.547615   -.2243394
_Icomm92a99 |      .0226   .3492935     0.06   0.948    -.6628331     .708033
_Icomm92a100 |  -1.727526   .3907112    -4.42   0.000    -2.494235   -.9608175
_Icomm92a101 |  -2.867931   .4041884    -7.10   0.000    -3.661086   -2.074775
_Icomm92a102 |   1.014971   .1786803     5.68   0.000     .6643393    1.365603
_Icomm92a103 |  -.9122642   .3705058    -2.46   0.014    -1.639323   -.1852055
_Icomm92a104 |  -.6095209   .3285144    -1.86   0.064    -1.254178    .0351366
_Icomm92a105 |  (dropped)
_Icomm92a106 |  -1.981655    .916783    -2.16   0.031    -3.780696   -.1826133
_Icomm92a107 |  -.8182702   .4652834    -1.76   0.079    -1.731315    .0947746
_Icomm92a108 |   .2701954   .2620661     1.03   0.303    -.2440678    .7844586
_Icomm92a109 |  (dropped)
_Icomm92a110 |  -2.315845    .368142    -6.29   0.000    -3.038265   -1.593424
_Icomm92a111 |   -1.08883   .4851615    -2.24   0.025    -2.040883   -.1367774
_Icomm92a112 |  -.4807054   .2603527    -1.85   0.065    -.9916062    .0301954
_Icomm92a113 |   .2966488   .2331108     1.27   0.203    -.1607941    .7540918
_Icomm92a114 |   -.668567   .3286473    -2.03   0.042    -1.313485   -.0236489
_Icomm92a115 |  -1.695834   .3529889    -4.80   0.000    -2.388518   -1.003149
_Icomm92a116 |   .0644237   .2550064     0.25   0.801     -.435986    .5648333
_Icomm92a117 |   -1.23573   .2507658    -4.93   0.000    -1.727818   -.7436422
_Icomm92a118 |  (dropped)
_Icomm92a119 |  -.9733886   .4326162    -2.25   0.025    -1.822329   -.1244478
_Icomm92a120 |  -2.048157    .271183    -7.55   0.000    -2.580311   -1.516004
_Icomm92a121 |  (dropped)
_Icomm92a122 |  (dropped)
_Icomm92a123 |  (dropped)
_Icomm92a124 |  (dropped)
_Icomm92a125 |  (dropped)
_Icomm92a126 |  (dropped)
_Icomm92a127 |  (dropped)
_Icomm92a128 |  (dropped)
_Icomm92a129 |  (dropped)
_Icomm92a130 |  (dropped)
_Icomm92a131 |  (dropped)
_Icomm92a132 |  (dropped)
_Icomm92a133 |  (dropped)
_Icomm92a134 |  (dropped)
_Icomm92a135 |  (dropped)
_Icomm92a136 |  (dropped)
_Icomm92a137 |  (dropped)
_Icomm92a138 |  (dropped)
_Icomm92a139 |  (dropped)
_Icomm92a140 |  (dropped)
_Icomm92a141 |  (dropped)
_Icomm92a142 |  (dropped)
_Icomm92a143 |  (dropped)
_Icomm92a144 |  (dropped)
_Icomm92a145 |  (dropped)
_Icomm92a146 |  (dropped)
_Icomm92a147 |  (dropped)
_Icomm92a148 |  (dropped)
_Icomm92a149 |  (dropped)
_Icomm92a150 |  (dropped)
_cons |   5.834788   .5632886    10.36   0.000     4.729423    6.940152
---------------------------------------------------------------------------

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```