ARE 106 HW 7

ARE 106 HW 7 - Jeff Phang ARE 106 HW 7 #1 Use an X-Y...

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Jeff Phang ARE 106 HW 7 #1 Use an X-Y scatter plot to plot TIME! on the X axis and GT4 on the vertical axis. Print this plot and paste it into your homework. Examine the plot: what do you see? -10 -8 -6 -4 -2  0  2  4  0  50000  100000  150000  200000  250000  300000  350000  400000 GT4 TIME There are systematic fluctuations of positive and negative trends with a spike in GT4 followed by a drop in GT4 every 100000 time units around the mean of approx -5. This is an example of auto correlation. Most of the observations are negative. 2. Run an Ordinary Least Squares (OLS) regression relating GT4 as the dependent variable to a constant and TIME as the independent variables, and report the results in standard format. a. Plot the Fitted and Actual against TIME. Briefly, does the model do a good or bad job in fitting the data? Model 1: OLS estimates using the 3311 observations 2001-5311 Dependent variable: GT4 coefficient std. error t-ratio p-value ---------------------------------------------------------
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const -4.63101 0.0846234 -54.72 0.000 *** TIME 7.84995E-07 4.98672E-07 1.574 0.1155 Mean of dependent variable = -4.52391 Standard deviation of dep. var. = 2.89627 Sum of squared residuals = 27744.8 Standard error of the regression = 2.89563 Unadjusted R-squared = 0.00075 Adjusted R-squared = 0.00045 Degrees of freedom = 3309 Durbin-Watson statistic = 0.0179302 First-order autocorrelation coeff. = 0.991011 Log-likelihood = -8217.36 Akaike information criterion (AIC) = 16438.7 Schwarz Bayesian criterion (BIC) = 16450.9 Hannan-Quinn criterion (HQC) = 16443.1 -10 -8 -6 -4 -2  0  2  4  0  50000  100000  150000  200000  250000  300000  350000  400000 GT4 TIME Actual and fitted GT4 versus TIME actual fitted GT4 hat = -4.63101 + 7.84995E-07 (TIME) R 2 = 0.00075 ( -54.72) (1.574)
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The Model does not do a good job estimating the data. The R 2 of 0.00075 indicates that the
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This note was uploaded on 04/11/2009 for the course ARE 106 taught by Professor Havenner during the Winter '09 term at UC Davis.

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ARE 106 HW 7 - Jeff Phang ARE 106 HW 7 #1 Use an X-Y...

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