Stata中的时间序列:var与回归

时间:2014-12-21 05:13:37

标签: time-series stata var

我正在寻找您对Stata中var和regress命令之间差异的见解。鉴于相同的变量和相同的滞后数,是什么使这些模型不同(根据其输出的差异来判断)?

var y x1 x2, lags(1/7)

regress L(1/7).y L(1/7).x1 L(1/7).x2 

该系列事先被转变为静止。

var y x1 x2, lags(1/7)

 Vector autoregression

 Sample:  9 - 159                                   No. of obs      =       151
 Log likelihood = -2461.622                         AIC             =  33.47844
 FPE            =  7.00e+10                         HQIC            =  34.01421
 Det(Sigma_ml)  =  2.90e+10                         SBIC            =  34.79725

 Equation           Parms      RMSE     R-sq      chi2     P>chi2
 ---------------------------------------------------------------
         y           22     627.086   0.4632   130.3037   0.0000
         x1           22     16.4642   0.4150   107.1156   0.0000
         x2           22     34.8932   0.3821   93.37647   0.0000
 ----------------------------------------------------------------

 ---------------------------------------------------------------------------------
                 |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
 ----------------+----------------------------------------------------------------
            y    |
               y |
             L1. |  -.8034219   .0870606    -9.23   0.000    -.9740576   -.6327862
             L2. |   -.829339   .1112633    -7.45   0.000    -1.047411    -.611267
             L3. |  -.6881525   .1268751    -5.42   0.000    -.9368231   -.4394818
             L4. |  -.5958702   .1316349    -4.53   0.000    -.8538699   -.3378706
             L5. |  -.4941909   .1285658    -3.84   0.000    -.7461752   -.2422066
             L6. |  -.3478784   .1130961    -3.08   0.002    -.5695426   -.1262142
             L7. |  -.1273106   .0892459    -1.43   0.154    -.3022294    .0476083
                 |
              x1 |
             L1. |   2.814694   4.697886     0.60   0.549    -6.392995    12.02238
             L2. |   13.40258   5.712821     2.35   0.019     2.205654     24.5995
             L3. |   13.41822   6.119334     2.19   0.028     1.424542    25.41189
             L4. |   7.634082   6.373183     1.20   0.231    -4.857128    20.12529
             L5. |   2.001271   5.898859     0.34   0.734     -9.56028    13.56282
             L6. |   3.421364   5.569404     0.61   0.539    -7.494468     14.3372
             L7. |   4.068799    4.46953     0.91   0.363    -4.691319    12.82892
                 |
              x2 |
             L1. |  -.5105249   2.210646    -0.23   0.817    -4.843312    3.822262
             L2. |  -2.108354   2.495037    -0.85   0.398    -6.998537     2.78183
             L3. |  -1.442043   2.592775    -0.56   0.578    -6.523789    3.639704
             L4. |  -.9065004   2.620667    -0.35   0.729    -6.042914    4.229913
             L5. |  -.0001391    2.53355    -0.00   1.000    -4.965806    4.965528
             L6. |   2.146481   2.427015     0.88   0.376    -2.610381    6.903343
             L7. |  -1.118613   2.118762    -0.53   0.598    -5.271309    3.034084
                 |
           _cons |   22.43668   48.04635     0.47   0.641    -71.73243    116.6058
 ----------------+----------------------------------------------------------------
         x1      |
               y |
             L1. |   .0036968   .0022858     1.62   0.106    -.0007833    .0081768
             L2. |   .0012158   .0029212     0.42   0.677    -.0045097    .0069413
             L3. |   .0035081   .0033311     1.05   0.292    -.0030208     .010037
             L4. |   .0032596   .0034561     0.94   0.346    -.0035142    .0100334
             L5. |   .0005852   .0033755     0.17   0.862    -.0060307     .007201
             L6. |  -.0018743   .0029693    -0.63   0.528    -.0076941    .0039455
             L7. |  -.0040389   .0023432    -1.72   0.085    -.0086314    .0005537
                 |
              x1 |
             L1. |  -.5753736   .1233434    -4.66   0.000    -.8171223   -.3336249
             L2. |  -.3020477   .1499906    -2.01   0.044    -.5960239   -.0080714
             L3. |  -.3313213   .1606637    -2.06   0.039    -.6462164   -.0164263
             L4. |  -.1718872   .1673285    -1.03   0.304    -.4998451    .1560707
             L5. |  -.1834757   .1548751    -1.18   0.236    -.4870253    .1200739
             L6. |   .0489376   .1462252     0.33   0.738    -.2376586    .3355337
             L7. |   .1766427   .1173479     1.51   0.132     -.053355    .4066404
                 |
              x2 |
             L1. |  -.1051509   .0580407    -1.81   0.070    -.2189086    .0086069
             L2. |  -.1006968   .0655074    -1.54   0.124     -.229089    .0276954
             L3. |  -.0906552   .0680736    -1.33   0.183    -.2240769    .0427665
             L4. |  -.1436015   .0688059    -2.09   0.037    -.2784585   -.0087445
             L5. |  -.0930764   .0665186    -1.40   0.162    -.2234505    .0372976
             L6. |  -.1018913   .0637215    -1.60   0.110    -.2267832    .0230006
             L7. |  -.1194924   .0556283    -2.15   0.032    -.2285218   -.0104629
                 |
           _cons |   1.918878   1.261461     1.52   0.128     -.553541    4.391296
 ----------------+----------------------------------------------------------------
              x2 |
               y |
             L1. |   .0010281   .0048444     0.21   0.832    -.0084667    .0105228
             L2. |  -.0038838   .0061911    -0.63   0.530    -.0160181    .0082505
             L3. |   .0035605   .0070598     0.50   0.614    -.0102764    .0173974
             L4. |   .0041767   .0073246     0.57   0.569    -.0101793    .0185327
             L5. |   .0007593   .0071538     0.11   0.915     -.013262    .0147806
             L6. |  -.0027897   .0062931    -0.44   0.658    -.0151239    .0095445
             L7. |   .0018272    .004966     0.37   0.713    -.0079059    .0115603
                 |
              x1 |
             L1. |   .3332696   .2614066     1.27   0.202     -.179078    .8456172
             L2. |   .6160613   .3178811     1.94   0.053    -.0069742    1.239097
             L3. |   .4139762   .3405009     1.22   0.224    -.2533934    1.081346
             L4. |   .2837896   .3546259     0.80   0.424    -.4112645    .9788436
             L5. |   .4448436   .3282329     1.36   0.175    -.1984811    1.088168
             L6. |   .6417029   .3099009     2.07   0.038     .0343084    1.249098
             L7. |   .4719593   .2487001     1.90   0.058    -.0154839    .9594025
                 |
              x2 |
             L1. |  -.7465681    .123008    -6.07   0.000    -.9876594   -.5054769
             L2. |  -.6760273   .1388325    -4.87   0.000     -.948134   -.4039206
             L3. |  -.4367948    .144271    -3.03   0.002    -.7195607   -.1540289
             L4. |  -.4889316    .145823    -3.35   0.001    -.7747393   -.2031238
             L5. |  -.5310379   .1409755    -3.77   0.000    -.8073447    -.254731
             L6. |  -.4416263   .1350475    -3.27   0.001    -.7063146   -.1769381
             L7. |  -.3265204   .1178952    -2.77   0.006    -.5575907     -.09545
                 |
           _cons |   3.568261   2.673465     1.33   0.182    -1.671634    8.808155
---------------------------------------------------------------------------------



regress L(1/7).y L(1/7).x1 L(1/7).x2

          Source |       SS       df       MS              Number of obs =     151
    -------------+------------------------------           F( 20,   130) =    7.23
           Model |  49291082.3    20  2464554.11           Prob > F      =  0.0000
        Residual |  44322342.8   130  340941.099           R-squared     =  0.5265
    -------------+------------------------------           Adj R-squared =  0.4537
           Total |  93613425.1   150  624089.501           Root MSE      =   583.9

    ---------------------------------------------------------------------------------
            L.y |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
    ----------------+----------------------------------------------------------------
               y |
             L2. |  -.8074369   .0868829    -9.29   0.000    -.9793244   -.6355494
             L3. |  -.7857941   .1076428    -7.30   0.000    -.9987525   -.5728357
             L4. |  -.6747462   .1186733    -5.69   0.000    -.9095271   -.4399654
             L5. |  -.5758927   .1192639    -4.83   0.000     -.811842   -.3399433
             L6. |  -.4199846   .1078154    -3.90   0.000    -.6332845   -.2066846
             L7. |  -.2444889   .0873128    -2.80   0.006    -.4172267    -.071751
                 |
              x1 |
             L1. |   9.174249   4.663798     1.97   0.051    -.0525176    18.40102
             L2. |   6.026435   5.730833     1.05   0.295    -5.311334     17.3642
             L3. |   13.03098   6.057813     2.15   0.033     1.046324    25.01564
             L4. |   13.01178   6.318175     2.06   0.041     .5120225    25.51153
             L5. |   6.146548    5.91807     1.04   0.301    -5.561646    17.85474
             L6. |   .8687361   5.610159     0.15   0.877    -10.23029    11.96776
             L7. |  -.6015264   4.502342    -0.13   0.894    -9.508873     8.30582
                 |
              x2 |
             L1. |   2.709283   2.214315     1.22   0.223    -1.671474    7.090041
             L2. |   2.947753   2.500195     1.18   0.241    -1.998585     7.89409
             L3. |   .7449778   2.611172     0.29   0.776    -4.420914    5.910869
             L4. |   .8159876   2.639117     0.31   0.758    -4.405191    6.037166
             L5. |   1.839693    2.54722     0.72   0.471    -3.199677    6.879062
             L6. |   2.267241   2.436901     0.93   0.354    -2.553876    7.088358
             L7. |   4.198018   2.102467     2.00   0.048     .0385389    8.357497
                 |
           _cons |  -3.078699   48.40164    -0.06   0.949    -98.83556    92.67816
 ---------------------------------------------------------------------------------

1 个答案:

答案 0 :(得分:0)

对我来说,他们有两种不同的规格。

第一个(VAR)正在估计三个自变量滞后对因变量(y,x1,x2)的影响。第二个是估计Lag从2:7的y + Lags对x1 + Lags(1:7)的x2 + Lags对因变量L(y)的影响。所以他们在y方面有两个不同的因变量和自变量。请参阅下面的等式(前三个用于var代码,最后一个用于regress代码):

enter image description here

OLS规范未考虑模型中变量之间存在的反馈效果。虽然你可能对X1对y的影响感兴趣,但X1也会受到y及其滞后值 - 反馈效应的影响。因此,使用OLS将导致虚假回归。