------------------------------------------------------------------------------- log: d:\bill\fall2008\econ30331\phillips_curve.log log type: text opened on: 29 Oct 2008, 10:50:21 . . * there are three variables in the data set . * year . * unemp (annual unemployment rate in %) . * inflation (annual inflation rate in %) . . . * The order of the time series . * data must be specified by an . * index. Here, we use year as the . * index . tsset year time variable: year, 1947 to 2007 delta: 1 unit . . * run classical phillips curve . . reg inflation unemp Source | SS df MS Number of obs = 60 -------------+------------------------------ F( 1, 58) = 4.06 Model | 33.5634573 1 33.5634573 Prob > F = 0.0486 Residual | 479.480783 58 8.26691005 R-squared = 0.0654 -------------+------------------------------ Adj R-squared = 0.0493 Total | 513.04424 59 8.69566509 Root MSE = 2.8752 ------------------------------------------------------------------------------ inflation | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- unemp | .5138821 .2550362 2.01 0.049 .0033718 1.024392 _cons | .9519491 1.474108 0.65 0.521 -1.998798 3.902696 ------------------------------------------------------------------------------ . . * get durbin watson statistic . estat dwatson Durbin-Watson d-statistic( 2, 60) = .8076584 . . * output residual . predict resid_a, residual (1 missing value generated) . . * lag the variable 1 period . gen resid_a1=resid_a[_n-1] (2 missing values generated) . . * estimate ar(1) term . reg resid_a resid_a1, noconst Source | SS df MS Number of obs = 59 -------------+------------------------------ F( 1, 58) = 30.13 Model | 154.739524 1 154.739524 Prob > F = 0.0000 Residual | 297.909892 58 5.13637744 R-squared = 0.3419 -------------+------------------------------ Adj R-squared = 0.3305 Total | 452.649415 59 7.67202399 Root MSE = 2.2664 ------------------------------------------------------------------------------ resid_a | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- resid_a1 | .568224 .1035255 5.49 0.000 .3609952 .7754529 ------------------------------------------------------------------------------ . . . *now estimate augmented Phillips Curve . * construct difference in inflation . gen inflation_1=inflation[_n-1] (1 missing value generated) . gen d_inf=inflation-inflation_1 (1 missing value generated) . . reg d_inf unemp Source | SS df MS Number of obs = 60 -------------+------------------------------ F( 1, 58) = 3.76 Model | 21.645692 1 21.645692 Prob > F = 0.0573 Residual | 333.612884 58 5.75194628 R-squared = 0.0609 -------------+------------------------------ Adj R-squared = 0.0447 Total | 355.258576 59 6.0213318 Root MSE = 2.3983 ------------------------------------------------------------------------------ d_inf | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- unemp | -.4126824 .2127343 -1.94 0.057 -.8385164 .0131517 _cons | 2.116596 1.229603 1.72 0.091 -.3447227 4.577914 ------------------------------------------------------------------------------ . estat dwatson Durbin-Watson d-statistic( 2, 60) = 1.546911 . . prais d_inf unemp, corc twostep Iteration 0: rho = 0.0000 Iteration 1: rho = 0.1559 Cochrane-Orcutt AR(1) regression -- twostep estimates Source | SS df MS Number of obs = 59 -------------+------------------------------ F( 1, 57) = 7.13 Model | 34.338162 1 34.338162 Prob > F = 0.0099 Residual | 274.681638 57 4.8189761 R-squared = 0.1111 -------------+------------------------------ Adj R-squared = 0.0955 Total | 309.0198 58 5.32792758 Root MSE = 2.1952 ------------------------------------------------------------------------------ d_inf | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- unemp | -.5934445 .2223151 -2.67 0.010 -1.038623 -.1482662 _cons | 3.269425 1.296032 2.52 0.014 .6741659 5.864685 -------------+---------------------------------------------------------------- rho | .1559494 ------------------------------------------------------------------------------ Durbin-Watson statistic (original) 1.546911 Durbin-Watson statistic (transformed) 1.978150 . . . end of do-file . log close log: d:\bill\fall2008\econ30331\phillips_curve.log log type: text closed on: 29 Oct 2008, 10:51:16 -------------------------------------------------------------------------------