(7)
y
=
β
0
+
β
1
C
h
o
i
c
e
+
β
2
S
V
s
p
e
n
d
+
β
3
S
V
s
a
v
e
+
β
4
S
e
q
S
V
+
β
5
S
e
q
L
e
n
g
t
h
+
β
6
C
u
e
p
o
s
i
t
i
o
n
+
β
7
L
e
f
t
/
r
i
g
h
t
+
β
8
S
e
q
u
e
n
c
e
p
r
o
g
r
e
s
s
+
ϵ
,