In studying the farm demand for tractors, Griliches used the following model*:
T * t = α X1,t-1β1 X2,t-1 β2
where T* = desired stock of tractors
X1 = relative price of tractors
X2 = interest rate
Using the stock adjustment model, he obtained the following results for the period 1921-1957:
l---og Tt = constant - 0.218 log X1,t-1 - 0.855 log X2,t-1 + 0.864 log Tt-1
(0.051) (0.170) (0.035)
R2 = 0.987
where the ?gures in the parentheses are the estimated standard errors.
a. What is the estimated coef?cient of adjustment?
b. What are the short- and long-run price elasticities?
c. What are the corresponding interest elasticities?
d. What are the reasons for high or low rate of adjustment in the present model?