demand for net monetary base with moment ratio-based standard errors j. huston mcculloch
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Demand for Net Monetary Base With Moment Ratio-based Standard Errors J. Huston McCulloch Ohio State University. US Monetary Base and Net Base = Base – interest-bearing XS Reserves. - PowerPoint PPT PresentationTRANSCRIPT
Demand for Net Monetary Base
With Moment Ratio-based
Standard Errors
J. Huston McCulloch
Ohio State University
US Monetary Base and Net Base = Base – interest-bearing XS Reserves
If XS reserves pay market interest rate, they represent financial intermediation and have no inflationary wealth effect.
log mt = c + a log yt + b Rt + t.
mt = Real Net Base yt = Real GDPRt = 3-mo T-Bill rate
Data via St. Louis Fed FRED data base
Nominal net base deflated with GDP deflator
All variables normalized to 0 in last quarter so that c measures excess D for m in last quarter (2011Q1).
A simple net base demand function
Data: Real GDP
Data: 3-Mo T-Bill Rate
Near 0 since 2009.Markets distorted 1980Q1 by Carter Credit Controls – T-bill rates shot down to 8%, Prime rate up to 20%+.
OLS regression results 1959Q1 – 2011Q1 (n = 209)
coef. OLS est. Standard errors(t-statistics)
OLS
c -0.0632 0.0120(-5.26)
a 0.8598 0.0111(77.30)
b -0.0391 0.0018(-21.37)
Standard errors small, t-stats huge!
OLS regression results 1959Q1 – 2011Q1 (n = 209)
coef. OLS est. Standard errors(t-statistics)
OLS
c -0.0632 0.0120(-5.26)
a 0.8598 0.0111(77.30)
b -0.0391 0.0018(-21.37)
Standard errors small, t-stats huge! But – DW = 0.154, p = 9.4e-92!
So OLS standard errors invalid
OLS regression results 1959Q1 – 2011Q1 (n = 209)
coef. OLS est. Standard errors(t-statistics)
OLS
c -0.0632 0.0120(-5.26)
a 0.8598 0.0111(77.30)
b -0.0391 0.0018(-21.37)
Standard errors small, t-stats huge!
Low-Tech solution: ignore problem
OLS regression results 1959Q1 – 2011Q1 (n = 209)
coef. OLS est. Standard errors(t-statistics)
OLS HAC(5)
c -0.0632 0.0120(-5.26)
0.0209(-3.03)
a 0.8598 0.0111(77.30)
0.0215(39.93)
b -0.0391 0.0018(-21.37)
0.0040(-9.78)
HAC se’s bigger, but t-stats still plenty big! Now “standard” correction for serial correlation.Easy radio button in EViews etc.
High-Tech solution: Use Newey-West HAC standard errors
Actual vs Predicted real Net Base
Long runs of +, - errors indicate positive serial correlation
Residuals persistent but appear to be stationary
But regression residuals typically less persistent, have smaller variance than true errors.
εXβy
||)'E( ji εεΓ
εXXXβyXXXβ ')'(')'(ˆ 11
11
11
)'(')'(
)'('')'(E
)ˆ(
XXΓXXXX
XXXεεXXX
βCovC
0|| / ΓR ji
OLS Regression with non-spherical stationary errors
X exogenous, includes const.
C depends on all autocovariances j
12 )'(ˆ XXC sOLS IΓ 0unbiased only if
MεεXXXXIβXye )')'((ˆ 1
1,,0)(tr1
njees j
jn
ijiij ee'
)),((
)(tr1
,
jdiagsum
ajn
ijiij
A
A
1,,0,/ 0 njssr jj
,)'E(E MΓMMεεMee'
)(tr)(trE 0 MRMMΓM jjjs
Residuals and Sample Autocorrelations
j-th order trace:
Newey-West HAC standard errors HAC = Heteroskedasticity and Autocorrelation Consistent Now routinely used as “correction” for serial corr.
11 )'(')'(ˆ XXFXXXXCHAC
choicebandwidth automatic 1)100/(4
function kernelBartlett )0,/)max(()k(
|)(|
9/2
nm
mlml
jikee jiF
,
Consistent because m, n/m as n .
But biased downwards with n < for 3 reasons:• Uses only first m-1 autocovariances• Downweights those by Bartlett factor• Uses e’s as if they were ’s -- MM in place of
,1 ttt u Eg AR(1) process = .9
• Higher order autocovariances just noise, so ignore• Lower order autocovariances reflect AR(1) process
• but start off too small,• decay too fast.
• NW is a step in wrong direction (m = 5 illustrated)
AR(p) Standard Errors AR(1) may be too restrictive. Instead, assume errors AR(p):
2
1
~, iiduu t
p
jtjtjt
Yule-Walker eqn’s determine R, G = /2 as a fn. of 1, ... p
and vice-versa.Standard Method of Moments estimates i by ri.
1 - mbandwidth NW )100/(4Set 9/2 np
so as to use same lags as NW without truncation or down-weighting.
OLS regression results 1959Q1 – 2011Q1 (n = 209)
coef. OLS est. Standard errors(t-statistics)
OLS HAC(5) AR(4)
c -0.0632 0.0120(-5.26)
0.0209(-3.03)
0.0375(-1.69)
a 0.8598 0.0111(77.30)
0.0215(39.93)
0.0361(23.82)
b -0.0391 0.0018(-21.37)
0.0040(-9.78)
0.0051(-7.40)
AR(4) SEs bigger, t-stats smaller But AR(4) SE’s still downward biased
jjttt u ,1
MM vs. in AR(1) model
0 20 40 60 80 100
0
50
1000.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Cov(), = 0.98, n = 100, var(t) = 1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 20 40 60 80 100
0
50
100-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Cov(demeaned residuals), = 0.98, n = 100, var(t) = 1
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 20 40 60 80 100
0
50
100-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
Cov(detrended residuals), = 0.98, n = 100, var(t) = 1
-0.1
0
0.1
0.2
0.3
0.4
True
MM (constant only) MM (trendline)
Residuals much less persistentthan errors themselves.
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-0.2
0
0.2
0.4
0.6
0.8
1
Moment Ratio function with distribution of r1 (trend line, n = 100)
Mon
te C
arlo
dis
tribu
tion
of r
1 = s
1/s0,
(,X
)=E
s1/E
s0
95%75%(,X)median
mean
25%5%
Monte Carlo Distribution of r1 in AR(1) model
Bias becomes acute as approaches 1!Bias similar for total persistence in AR(p) model
0 0.2 0.4 0.6 0.8 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Moment Ratio Bias in r1 (trend line model, n = 100)
true
(
,X)
= E
s 1/Es 0
(,X)
45 deg
Moment Ratio Estimator in AR(1) case r1 = s1/s0 is ratio of 2 sample moments
Moment Ratio Function:
is ratio of population moments consistently est. by s1, s0.
)(/tr)(tr);(ψ 011 MRMMRMX
Moment Ratio Estimator -- AR(1) case
)(/tr)(tr);ψ( 011 MRMMRMXr );(ψˆ1
1 XrMR
0 0.2 0.4 0.6 0.8 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1Moment Ratio estimator of (trend line model, n = 100)
r1 = s
1/s
0
hat MR
-1(r1,X)
45 deg
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-0.2
0
0.2
0.4
0.6
0.8
1
Moment Ratio function with distribution of r1 (trend line, n = 100)
Mon
te C
arlo
dis
tribu
tion
of r
1 = s
1/s0,
(,X
)=E
s1/E
s0
95%75%(,X)median
mean
25%5%
Moment Ratio function Monte Carlo median
MR Estimator approximately median unbiased without costly simulation of Andrews (1993).
pp
pMM
s
s
ss
ss
1
1
01
10
φ
.
tr
tr
trtr
trtr
E
E
EE
EE
;1
1
01
101
1
01
10
MGM
MGM
MGMMGM
MGMMGM
Xφψ
pp
p
pp
p
s
s
ss
ss
Xφψφφφ
,ˆminargˆ
MMMR
MR(p) Estimator
so define
then numerically solve
Constrained Nelder-Mead sol’n of MR eq’ns:
N = 100, p = 4, tol = .001: 107 iterations, 0.4 sec on ordinary laptop.Circles = AR(p) starting point, boxes = MR(p) sol’n.
Unit Root does not imply spurious regression! but requires reformulating problem. ADF / Andrews & Chen (94) persistence form w/ = 1:
p
jhhj
p
jjt
p
jjtjtjtt u
11
1
111 .,
2211 /,Cov ttttHYule-Walker gives
matrix integrator is ,)|Cov( 20 ji NNHN'ε
MNHNMee 20 Cov|Cov
pjs jj ,1),(trE 2 MNHNM
Monte Carlo bias, size distortion of MR(p) trendline regression, n = 100, p = 4, AR(1) DGP, 10,000 reps
Median squared SE of slope coefficient / true variance:
MR(p) dominates AR(p), HAC, OLS i.t.o. median biasUnless very near 0
Coverage of 95% CI for slope (full graph)
Coverage of 95% CI for slope (detail of previous slide)
MR(p) outperforms others.Use Student t with reduced DOF?
MMj
MRjlag j ri
1 0.913 1.117 1.159
2 0.808 -0.393 -0.433
3 0.735 0.405 0.453
4 0.639 -0.235 -0.251
0.895 0.927
MR vs MM AR(4) coefficient estimates:
MR raises persistence, but still short of unit root.
OLS regression results 1959Q1 – 2011Q1 (n = 209)
coef. OLS est. Standard errors(t-statistics)
OLS HAC(5) AR(4) MR(4)
c -0.0632 0.0120(-5.26)
0.0209(-3.03)
0.0375(-1.69)
0.0517(-1.22)
a 0.8598 0.0111(77.30)
0.0215(39.93)
0.0361(23.82)
0.0503(17.08)
b -0.0391 0.0018(-21.37)
0.0040(-9.78)
0.0051(-7.40)
0.0071(-5.54)
MR(4) se’s bigger than AR(4), but a, b still significant! However, c, although large, is insignificant.
Issues for future work:
• Implement Unit Root test,• Find rule for when to impose unit root
• Properties with Long Memory errors?
• Regressor-Conditional Heteroskedasticity • White / NW-type modification?
0 20 40 60 80 100
0
50
100-10
-5
0
5
10
15
Cov(detrended residuals), = 1, n = 100, var(ut) = 1
-4
-2
0
2
4
6
8
10
12
Thank you! Questions?
The AR(1) Unit Root case = 1
02
00 )|'E( WεεΓ u
),max(0 jiW
MWMeeee 02
0 )|'E('E u
)(trE 02 MWMjujs
)(/tr)(tr);1ψ( 0001 MWMMWMX
)(tr/ˆ 0002 MWMsu
0 20 40 60 80 100
0
50
1000
20
40
60
80
100
Cov(|0 = 0), = 1, n = 100, var(u
t) = 1
10
20
30
40
50
60
70
80
90
100
0 20 40 60 80 100
0
50
100-20
-10
0
10
20
30
40
Cov(demeaned residuals), = 1, n = 100, var(ut) = 1
-15
-10
-5
0
5
10
15
20
25
30
0 20 40 60 80 100
0
50
100-10
-5
0
5
10
15
Cov(detrended residuals), = 1, n = 100, var(ut) = 1
-4
-2
0
2
4
6
8
10
12