Econometrics
Individual Assignment for J results
i)
What is the part of the variation in sales which is not explained by the regression line?
ii)
Estimate the price elasticity of sales.
2. The following table includes the GNP(X) and the demand for food (Y) for a country over ten years
period.
year 1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
Y
6
7
8
10
8
9
10
9
11
10
X
50
52
55
59
57
58
62
65
68
70
a. Estimate the food function
b. Compute the coefficient of determination and find the explained and unexplained variation in
the food expenditure.
c. Compute the standard error of the regression coefficients and conduct test of significance at
the 5% level of significance.
3. A sample of 20 observation corresponding to the regression model Yi     X i  U i gave the
following data.
 Y  21.9
 X  186.2
  X  X Y  Y   106.4
i
i
i
 Y  Y   86.9
  X  X   215.4
2
i
2
i
i
a. Estimate  and 
b. Calculate the variance of our estimates
c. Estimate the conditional mean of Y corresponding to a value of X fixed at X=10.
4. Suppose that a researcher estimates a consumptions function and obtains the following results:
C  15  0.81Yd
(3.1)
(18.7)
n  19
R 2  0.99
The number in parenthesis is t _value
where C=Consumption, Yd=disposable income, and numbers in the parenthesis are the ‘t-ratios’
a. Test the significant of Yd statistically using t-ratios
b. Determine the estimated standard deviations of the parameter estimates