48 Methodology of Empirical Econometric Modeling
1920 1940 1960 1980–12.5–12.0 a ef^e1920 1940 1960 1980–0.250.00b pf−p1920 1940 1960 1980–11.5–11.0–10.5–10.0 c1920 1940 1960 19800.00.10.20.3
d s1920 1940 1960 1980–0.10.00.1 e Δef1920 1940 1960 19801.01.21.41.6 f
log family sizeFigure 1.6 Food expenditure and related time series
ona, and was selected by Autometrics at 1% for all candidate variables, including
impulse saturation. All diagnostic tests were insignificant, and the PcGive unit root
test strongly rejected the null of no cointegration (tur=−11.37∗∗: (see Banerjee
and Hendry, 1992; Ericsson and MacKinnon, 2002) with the long-run solution:
c 0 =ef+7.99−0.4e+0.36(pf−p). (1.39)Transforming to differences and the equilibrium-correction term from (1.39),
Autometrics selected over 1931–89 (at 2.5%, again including impulse saturation):
ef,t= 0.34
(0.02)st− 1 − 0.32
(0.02)c0,t− 1 + 0.67
(0.04)et+ 0.13
(0.03)et− 1− 0.64
(0.03)(pf−p)t− 0.09
(0.01)I 31 − 0.10
(0.01)I 32 + 0.04
(0.01)I 34+ 0.03
(0.01)I 41 + 0.05
(0.01)I 42 + 0.03
(0.01)I 51 + 0.02
(0.01)I 52 + 0.03
(0.01)I 70(
R∗) 2
=0.96FM(13, 45)=94.9∗∗̂σ=0.0078Far(2, 44)=1.34χ^2 (^2 )=1.04Farch(1, 44)=2.25Freset(1, 45)=0.35
Fhet(18, 27)=0.48FChow(9, 37)=0.99. (1.40)