Title: Spatial Econometric Models of Interdependence Theory
1Spatial Econometric Modelsof InterdependenceThe
ory Substance Empirical Specification,
Estimation, Evaluation Substantive
Interpretation Presentation
- Talk prepared for Blalock Lecture on
- 7 August 2008 at the ICPSR Summer School
- based on the joint work of
- Robert J. Franzese, Jr., The University of
Michigan - Jude C. Hays, The University of Illinois
2Overview
- Motivation Integration Domestic
Policy-Autonomy - Does economic integration constrain govts from
redistributing income, risk, opportunity
through tax spending policies? - In answering this related questions, scholars
have overlooked spatial interdependence of
domestic policies as important evidence. - Economic integration generates externalities
across political jurisdictions, which implies
strategic policy interdependence, so policy of
one govt will be influenced by policies of its
neighbors. - Interdependence Substance, Theory, Empirics
Use contexts econ integration ( related) to
explore explain - Substance is actions depend on js. Examples.
- Theory
- General externalities?strategic policy
complements/substitutes?race-to-bottom/top/else?ea
rly/late-mover advantages?strategic
delay/rush-for-1st - Specific a model of inter-jurisdictional
tax-competition (PT ch. 12) - Empirics Galtons Problem Estimation,
Inference, Interpretation, Presentation
3A Motivating ContextGlobalization
Domestic-Policy Autonomy
- Standard Argument
- ? capital mobility trade integration sharpen
capitals threat vs. domestic govts to flee
excessive/inefficient tax public policy forces
welfare-state retrench tax shift from more-mob.
cap. (esp. finance) to less-mob. lab. (esp.
skilled-man.) - Recent counter-arguments findings
- Some empirical Q whether constrained or
constraint from trade/capital integ. - Counter-arguments (e.g.)
- Rodrik (Cameron) Demand (contra supply) SocPol
may ? w/ integ ? indeterminate - Garrett 98/Boix 98 Left/active govt more/as
efficient ? capital not flee - Hall-Soskice 01/Franzese-Mosher 02 comparative
institutional advantage ? trade-integ foster
divergence (liquid) cap-integ may foster race to
bottom (not necly) zero - Swank 02 ( many others) political economic
barriers /or advantages ? considerable
maneuvering room - Standard all counter arguments ? spatial
interdependence b/c whatever pressures may arise
from globalization depend on what neighbors,
competitors, partners, substitutes, complements
do - Accordingly, appropriate model places others
policies on right-hand side - Basinger-Hallerberg 04 maybe 1st in CIPE to
notice incorporate explicitly - Interdependence (def) yif(yj?i) note not
merely that yi yj?i corr
4The Broad Range of Spatial Interdependence
- Theoretical Contexts (ubiquitous)
- ANY Strategic Decision-making si?sj
- Externalities Spillovers
- Learning/Emulation, Demonstration
- Networks/Epistemic Communities
- Literal Diffusion, Contagion, Migration
- (Simmons et al.s 06) Mechanisms
- Competition
- Coercion
- Learning
- Emulation
- Migration/Contagion (FH Add)
- Substantive Contexts (ubiquitous)
- Security Policy (e.g., alliances, wars)
- Environmental (e.g., air-pollution reg)
- Regulatory (e.g., telecomm stds)
- Legis reps votes depend on others
- Elects., cand. qualities or strategies
- p()outs coups (LiThompson 75), riots
(GoveaWest 81), revolts (BrinksCopp 06) - Contextual effects in micro-behavior
- BraybeckHuckfeldt 02ab, Cho 03, Huckfeldt et al.
05, ChoGimpel 07, ChoRudolph 07, Lin et al 06
- Policy, instits, regimes diffusion
- Policy SchneiderIngram88, Rose 93, Meseguer
04,05, Gilardi 05 - Institutional or regime Implicit/Informal
Dahls Polyarchy, Starrs Democratic Dominoes,
Huntingtons 3rd Wave. Explicit/Formal
OLoughlin et al. 98, Brinks Coppedge 06,
Gleditsch Ward 06, 07 - Intl diffusion of liberalization
- SimmonsElkins 04, 06a, 06b, Eising 02, Brune et
al. 04, Brooks 05 - Globalization interdependence
- Genschel 02, BasingerHallerberg 04, Knill 05,
Jahn 06, Swank 06, FH 06,07, Kayser 07
- Toblers Law I invoke the first law of
geography everything is related to everything
else, but near things are more related than
distant things (1970). - Plus Space More Than Geography (Beck,
Gleditsch, Beardsley 2006)
5Substantive Theoretical Ubiquity Centrality
(1)
- US State Policy-innovation diffusion deep roots
much contemporary interest, sustained
attention between - Crain 1966 Walker 1969, 1973 Gray 1973 Knoke
1982 Caldiera 1985 Lutz 1987 Berry Berry
1990 Case et al. 1993 Berry 1994 Rogers 1995
Mintrom 1997ab Brueckner 1998 Mintrom Vergari
1998 Mossberger 1999 Berry Berry 1999 Godwin
Schroedel 2000 Balla 2001 Mooney 2001
Wejnert 2002 Coughlin et al. 2003 Bailey Rom
2004 Boehmke Witmer 2004 Daley Garand 2004
Grossback et al. 2004 Mencken 2004 Berry
Baybeck 2005 Garrett et al. 2005 Costa-Font
Ons-Novell 2006 Karch 2006 Rincke 2006 Shipan
Volden 2006 Volden 2006 Werck et al. 2006
Woods 2006 Volden et al. 2007. - Similar policy-learning mechanisms underlie some
comparative studies of policy diffusion - Schneider Ingram 1988 Rose 1993 Bennett 1997
Dolowitz Marsh 2000 True Mintrom 2001 Tews
et al. 2003 Jensen 2004 Meseguer 2004, 2005
Brooks 2005, 2007 Gilardi 2005 Gilardi et al.
2005 Murillo Schrank 2005 Weyland 2005 Braun
Gilardi 2006 Linos 2006 Parys 2006 Ermini
Santolini 2007 Moscone et al. 2007. - Institutional or regime diffusion likewise
long-standing recently much reinvigorated - Dahls 1971 Polyarchy (1 of 8 causes dem listed)
center-stage Starrs 1991 Democratic Dominoes
Huntingtons 1991 Third Wave Beissinger 2007
Bunce Wolchik 2006, 2007 et al. in E. Eur.
Transitions Hagopian Mainwaring 2005 et al. in
LA OLoughlin et al. 1998, Brinks Coppedge
2006, Gleditsch Ward 2006, 2007 estimated
empirically extent, paths, /or patterns dem
diffuse. Kelejian et al. 2007 give institutional
diffusion general theoretical empirical
treatment. - CIPE, e.g. globalizationinterdependence
- Diffusion of Liberalization Related Simmons
Elkins 2004, Simmons et al. 2006, Eising 2002
Brune et al. 2004 Brooks 2005, 2007 Jordana
Levi-Faur 2005 Way 2005 Lazer 2006 Prakash
Potoski 2006 Brune Guisinger 2007 and many
others. - Glob/Interdep/TaxComp Dom Policy Auton
Genschel 2002 Guler et al. 2002 Franzese Hays
2003, 2004b, 2005a, 2007abc, 2008c Badinger et
al. 2004 Basinger Hallerberg 2004 Heichel et
al. 2005 Henisz et al. 2005 Holzinger Knill
2005 Knill 2005 Polillo Guillén 2005 Elkins
et al. 2006 Jahn 2006 Lee Strang 2006 Manger
2006 Swank 2006 Baturo Grey 2007 Cao 2007
Cao et al. 2007 Coughlin et al. 2007 Garretsen
Peeters 2007 Mosley Uno 2007 Mukherjee
Singer 2007.
6Substantive Theoretical Ubiquity Centrality
(2)
- Representatives votes (Lacombe Shaughnessy
2005), citizens votes (Huckfeldt Sprague 1991
OLaughlin et al. 1994 Pattie Johnston 2000
Beck et al. 2003 Calvo Escolar 2003 Kim et
al. 2003 Schofield et al. 2003 Lacombe
Shaughnessy 2007), election outcomes (Shin
Agnew 2002, 2007 Hiskey Canache 2005 Wing
Walker 2006 Kayser 2007), candidate qualities,
contributions, or strategies (Goldenberg et al.
1986 Mizruchi 1989 Krasno et al. 1994 Cho
2003 Gimpel et al. 2006) - Probabilities outcomes of coups (Li Thompson
1975), riots (Govea West 1981), civil wars
(Murdoch Sandler 2004, Buhaug Rød 2006) /or
revolutions (Brinks Coppedge 2006) - IR interdepdefinition of subject
- States entry into wars, alliances, treaties
(Murdoch et al. 2003), or organizations. - Empirical attention to inherent spat-dep IR
greatest in Shin Ward 1999 Gleditsch Ward
2000 Gleditsch 2002 Ward Gleditsch 2002 Hoff
Ward 2004 Gartzke Gleditsch 2006 Salehyan
Gleditsch 2006 Gleditsch 2007, and, in different
way, Signorino 1999, 2002, 2003 Signorino
Yilmaz 2003 Signorino Tarar 2006 - In micro-behavioral work, too, long-standing
surging interest contextual or neighborhood
effects - Huckfeldt Sprague 1993 review, some of which
stress interdep Straits 1990 OLoughlin et al.
1994 Knack Kropf 1998 Liu et al. 1998
Braybeck Huckfeldt 2002ab Beck et al. 2002
McClurg 2003 Huckfeldt et al. 2005 Cho Gimpel
2007 Cho Rudolph 2007. Sampson et al. 2002 and
Dietz 2002 review the parallel large literature
on neighborhood effects in sociology - At beyond other disciplinary borders, subjects
include - Social-movements McAdam Rucht 1993 Conell
Cohn 1995 Giugni 1998 Strang Soule 1998
Biggs 2003 Browning et al. 2004 Andrews Biggs
2006 Holmes 2006 Swaroop Morenoff 2006. - Microeconomic preferences Akerloff 1997
Postlewaite 1998 Glaeser Scheinkman 2000
Manski 2000 Brock Durlauf 2001 Durlauf 2001
Glaeser et al. 2003 Yang Allenby 2003 Sobel
2005 Ioannides 2006 Soetevent 2006 - Macroeconomic performance Fingleton 2003 Novo
2003 Kosfeld Lauridsen 2004 Maza Villaverde
2004 Kelejian et al. 2006 Mencken et al. 2006 - Technology, marketing, and other firm strategies
Abramson Rosenkopf 1993 Geroski 2000 Strang
Macy 2001 Holloway 2002 Bradlow 2005
Autant-Berard 2006 Mizruchi et al. 2006 - Violence and crime Grattet et al. 1998 Myers
2000 Baller et al. 2001 Morenoff et al. 2001
Villareal 2002 Baker Faulkner 2003
Oberwittler 2004 Bhati 2005 Mears Bhati 2006
Brathwaite Li 2008 - Fertility, birthweight, child development,
child poverty Tolnay 1995 and Montgomery
Casterline 1996 Morenoff 2003 Sampson et al.
1999 Voss et al. 2006 - Not to mention public health and epidemiology
(contagion!). - More exotic topics ordainment of women (Chaves
1996), right-wing extremism (Rydgren 2005),
marriage (Yabiku 2006), national identity (Lin et
al. 2006), faculty (Weinstein 2007).
7Policy InterdependenceA General Theoretical
Model (Brueckner 03)
- is utility depends pi pj b/c interdep ( vv)
- Accordingly, is optimal policy, pi, depends js
action, pj - So slope best-response function depends on effect
of pj on marginal utility of pi - Therefore Diminishing returns and
- negative externalities gtstrategic complements
- Positive slope positive feedback/same-signed
reactions - positive externalities gt strategic substitutes
- Negative slope neg. feedback/opposite-signed
reactions
8Policy InterdependenceGeneral Theory
Substantive Implications
- Dimin returns neg externalities ? Strategic
Complements - ? Race-to-Bottom (RTB) (or -Top). Examples
- Tax Competition
- Labor Regulation
- Trade Barriers (politically)
- ? Early-mover advantage ? race to go first
- E.g. Exch.Deprec., tech.stds. ( other focal
pts. in coord. or battle sexes) - Dimin returns pos externalities ? Strategic
Substitutes - ? Free-Riding Incentives
- E.g., Alliance Security
- E.g., ALMP
- ? Late-mover advantage ? strategic delay Wars
of Attrition - DimRet both externs
- Environmental Regs ( CHIPs?)
9Figure 2. Best Response Functions Strategic
Substitutes
10An International Tax-Competition Model as a
Specific Substantive Example of Interdependence
- Stylized Theoretical Model Cap-Tax Comp. (PT
00, ch.12) - 2 jurisdicts, dom for cap-tax, tk tk to fund
fixed spend. For-invest mobility costs, M. - Inds lab-cap endow, ei, choose lab-leisure, l
x, save-invest, skf to max ?U(c1)c2V(x),
over l, c1, c2, s.t. time-c., 1eilx,
b.c.s, 1eic1kfc1s c2(1tk)k(1tk)fM(
f)(1tl)l. - ? equilibrium economic choices of citizens
- ? indirect utility, W, defined over policy
variables, tl, tk, tk - Besley-Coate (97) citizen-candidate(s) face(s)
electorate w/ these prefs. - Stages 1) elects, 2) cit-cand winners set taxes,
3) all private econ decisions made. - Ebm win cand has endow eP such that desires
implement this Modified Ramsey Rule - ? Best-Response Functions tkT(eP,tk)
tkT(eP,tk) for dom for pm. - Slopes ?T/?tk ?T/?tk, pos or neg b/c ?tk ?
cap-inflow can use ?tax-base to ?tk or to ?tk
(seizing upon ?elasticity base). - Background of this slide plots case both
positively sloped illustrated comparative static
is of leftward shift of domestic government.
11Empirical Models of InterdependenceGaltons
Problem in CIPE
- Interdependence ? yif(yj)
- Generic (linear) dynamic spatial-lag model of
CIPE - Galtons Problem Extremely difficult disting why
C(yi,yj) b/c... - 1. Correlated domestic/unit-level conditions, d
(CPE) - 2. Common/corrd exposure exog-external
shocks/conditions, s (open-CPE) - 3. Responses to these 2 may be context-conditional
, s?d (CC-CPE) - 40. Correlated stochastic component (Beck-Katz),
nuisance CIPE - 4. Interdependence/diffusion/contagion
yif(yj,CC-CPE), substance CIPE - Upshot Empirically (Franzese Hays
03,04,06ab,07abcd,08ab) - omit or mis-specify CPE, tend over-estimate IPE
(interdependence) v.v. - yi?yj gt textbook endogeneity/simultaneity
problem w/ spatial lag analogous - fail redress endog sufficiently ? mis-est (usu.
over-est.) ? ? (under)mis-est. ß - Most Important Conclusion Model It!TM Insofar as
omit or relly mis-spec spatial interdep, tend
over-est impact domestic exog-ext factors
v.v. ? most crucial, regardless of CPE/IPE
emphasis well-spec model measure both. - S-OLS may suffice. OVB gtgt simultaneity bias in
any of practical examples weve considered,
S-OLS did OK our MCs provided interdep remained
modest (?lt.3).
12The Terms of Galtons ProblemOmitted-Variable
vs. Simultaneity Biases inSpatial- and
Spatio-Temporal-Lag Models
- OVB (rel. mis-spec.) v. simultaneity
- OVB (OLS)
- SimB (S-OLS)
- In S-T, little more complicated, but
With all positive S-T dep, ? space-dep over-estd
? time-dep ß under-estd
13Estimating Spatial/Spatio-Temporal-Lag Models
- Inconsistent Estimators
- Omit spatial-dep (e.g., OLS) bad idea if ?
non-negligible - Ignore simultaneity (e.g., S-OLS) could be OK
(in MSE) if ? not too large sample-dims
benevolent - Simplest Option, if Available
- Time-Lagged Spatial-Lag OLS easy unbiased iff
- No contemporaneous (i.e., w/in obs period)
interdependence. - Model of temporal dynamics sufficiently accurate
(see Achen) - 1st obs pre-determined if not, spatial-Hurwicz
bias (order 1/T) - Consistent Estimators
- S-IV/2SLS/GMM Use WX to instrument Wy, etc.
- S-ML Specify system for Max-Likelihood estimation
14Estimating Spatial- Spatio-Temporal-Dynamic
Models by S-ML
- S-ML for Spatial-Lag Model
- Std, but e ? y by A not 1 ? computational
issues, plus - Conditional S-ML S-T (ie., given 1stobs, Nx1
form) (unconditional is messy but exists wont
show) - Stationarity (if row-stdzd, ?,?gt0) ??lt1
- Spatial Probit complicated but doable (show if
time) - m-STAR Estd W endog W doable (show if)
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21APPLICATIONS
- Globalization, Tax Competition, Domestic Policy
- Replicates SwankSteinmo 02, Hays 03,
BasingerHallerberg 04 - ALMP Active-Labor-Market Policy in EU (FH 06)
- DepVar LMT spend per unemployed worker
- Hypoth Positive spillovers (_at_ borders) effective
member-state ALMP ? free-riding underinvest.
Appreciable? - IndVars rGDPpc, UE, UDen, Deindustrialization
(Iversen-Soskice), Trade, FDI, Pop65, LCab,
CDemCab, LLibVote, GCons - MIDs Trade Beck, Gleditsch, Beardsley 06
- DepVar Directed trade data
- Hypoth MIDs affect trade in beyond dyad
- IndVars GDPab, POPab, Distance, tau-b,
MutualDem, MID, Bi/MultiPoleSys - AFDC CHIPs in U.S. States (Volden 06)
- AFDC Hypothstates as laboratoriesdiffusion
by learning - DepVar max monthly AFDC benefit
- Ind Vars states poverty rate, avg monthly wage
in retail, govt ideology (0-100, R-L), º
interparty competition (.5-1.0, comp-non), tax
effort (rev as tax capacity), AFDC bens
paid by fed govt. - CHIPs Hypothstates as laboratoriesdiffusion
by learning - DepVar 1 if states CHIP includes monthly
premium IndVars same.
22Practical Model Specification Estimation
- Most convenient to work in (Nx1) vector form
- WNan NxN of (time-invariant) spatial wts, wij,
WN?IT gives W. - E.g., 15x15 binary-contiguity from ALM paper
- N.b., row-stdz typ., convenient, but not necly
substly neutral - Ideally, substance, which not necly ? geography,
in W. - Beware of extant software critical bug in
LeSages MatLab code likelihood in some
third-party Stata SAR code seems flat wrong.
23Swank Steinmo APSR 02 Replication
24Hays IO 03 Replication
25Basinger Hallerberg APSR 04 Replication
26Beck, Gleditsch, Beardsley ISQ 06 Replication
27Franzese Hays EUP 06
28Volden AJPS 06 AFDC Replication
29Volden AJPS 06 CHIPs Replication
30Interpreting Spatial/Spatio-Temporal Effects
- The Model
- Model may look linear, but is not as in all
beyond purely linear-additive, coefficients
effects very different things! - Convenient, for interpretation, to write model
this way too - Coefficients, ßx are just pre-spatial,
pre-temporaland wholly unobservable!impulse
from some x to y. - Spatio-Temporal Effects
- Post-spatial, pre-temporal instantaneous effect
of x - Spatio-Temporal Response Paths
- LR Multiplier/LR-SS
31Presenting Spatial/Spatio-Temporal Effects
- Standard Errors (Confidence Intervals
Hypothesis Tests) of Effects - Delta Method
- or Simulate!
- Upshot Cannot see substance clearly from only
the estimated coefficients their standard
errors - Effective Presentational Options
- SR/LR-Response Grids
- Spatio-Temporal Response-Paths
- Maps
32Swank Steinmo APSR 02 Replication
33Swank Steinmo APSR 02 Replication
34Swank Steinmo APSR 02 Replication
35Basinger Hallerberg APSR 04 Replication
36Basinger Hallerberg APSR 04 Replication
37Beck, Gleditsch, Beardsley ISQ 06 Replication
38Beck, Gleditsch, Beardsley ISQ 06 Replication
39Beck, Gleditsch, Beardsley ISQ 06 Replication
40Franzese Hays EUP 06
41Franzese Hays EUP 06
42Some Other Presentations (3)
43Volden AJPS 06 AFDC Replication
44Volden AJPS 06 AFDC Replication
45Volden AJPS 06 AFDC Replication
46Conclusion
- Spatial Spatio-Temporal Interdependence
- Important Appreciable Substance (e.g.,
globalization intl cap-tax compete seems quite
real does constrain), not Nuisance. - Therefore Model them. Interpret them.
- How specify estimate models?
- If space-lag is time-lagged, not problem but if
thry substance says immediate (w/in an
observational period), can handle that too - S-OLS not a bad strategy even then, if ? not too
big smpl-dims right S-ML, in some regards
IV-based strategies, seem effective - Spatio-Temporal Effects not directly read from
coefficients use graphs maps grids - Information-demands of Galtons Problem severe ?
- Standard errors of effects tend big. Suspect
delta-method lin-approx. maybe part problem plan
explore performance bootstrap. - Max effort care theory, measure, specification,
to both CIPE
47Spatial QualDep The Econometric Problem (1)
- Spatial Qualitative/Categorical/Lmtd-Dep-Var
Models in the Lit - Spatial probit McMillen 1992,1995 Bolduc et.
al. 1997 Pinkse Slade 1998 LeSage 1999, 2000
Beron et al. 2003 Beron Vijverberg 2004 - Spatial logit Dubin 1997 Lin 2003
Autant-Bernard 2006 - Spatial sample-selection (i.e., s-Tobit/Heckit)
McMillen 1995, Smith LeSage 2004,
Flores-Lagunes Schnier 2006 - Spatial multinomial-probit McMillen 1995, Bolduc
et al. 1997 - Spatial discrete-duration Phaneuf Palmquist
2003 - Survival w/ spatial frailty Banerjee et al.
2004, Darmofal 2007 - Spatial count Bhati 2005, including ZIP Rathbun
Fei 2006 - The Challenge
- Not n indep., unidimensional CDF std normals, so
(log-)likelihoodproduct (sum) thereof, but 1
n-dimensional CDF of non-std (heterosked.)
normals - Spatial Latent-Variable Models Estimation
Strategies - McMillen 1992 EM algorithm, rendered spatial
probit estimable, but no std-errs arb.
parameterization of induced heteroscedasticity. - McMillen 1995, Bolduc et. al. 1997
simulated-likelihood strategies to estimate
spatial-MNP - Beron et al. 03, Beron Vijverberg 04
recursive-importance-sampling (RIS) estimator - LeSage 1999, 2000 Bayesian strategy of
Markov-Chain-Monte-Carlo (MCMC) by
Metropolis-Hastings-within-Gibbs sampling. - Fleming 2004 simpler, if approximate, strategies
allowing interdep. in (non)linear probability
models, estimable by NLS, GLM, or GLMM - Pinkse Slades 1998 two-step GMM estimator
(for spatial-error probit).
48The Econometric Problem (2)
- Structural Model
- Reduced Form
- Measurement Equation
- Probability
- Or
- For Spatial-Error-Probit
49The Econometric Problem (3)
- Comments
- Notice that, when we come to interpret
, we face the same MVN integration - We havent seen such substantive interpretation
yet attempted fully in the literature, but we
suggest an easier way to do it. - If can order dependence pattern ensure only
antecedent y appear on RHS, then std probit ML
w/ a spatial-lag works - We think usu. indefensible substly/thryly, but
cf. Swank on capital-tax competition, e.g., where
argues US exclusively leads omits US. - Having y, not y, on RHS may seem substly or
thryly desirable in some cases, but genly not
logically possible - Problem would be that outcome, yi, would
indirectly (via spatial feedback) determine yi,
but then yi would directly determine yi. The
stochastic difference b/w them will thus ? a
logical inconsistency. - Notice similar MVN issue w/ time lags suggests
similar strategies (but simpler b/c ordered) may
allow model temp dynamics directly rather than
nuisance (e.g., BKT splines)
50The Estimators Bayesian Gibbs-MH Sampler (1)
- Basic Idea (See Gills intro Bayesian textbook,
e.g.) - Monte Carlo (MC) Given likelihood/posterior, can
sample to estimate any quantity of interest,
including density, e.g. - Markov Chain (MC)MC
- Each draw depends on previous, so need only
conditional like./post. - Some theorems indicate, under fairly genl
conditions, distribution parameter draws
converges to distribution under true like./post. - Gibbs Sampler simplest of MCMC family
- Express each parameter like./post. conditional on
others. - Cycle to draw each conditional on others starts
or previous draw - After some sufficient burn-in, all subsequent
param-vector draws follow true multivariate
likelihood/posterior. - Metropolis-Hastings useful when condl
param-dist non-std - Draws from a seed or jump distribution are
accepted or rejected as the next sampled
parameters, depending on how they compare to a
suitably transformed expression of the target
distribution
51The Estimators Bayesian Gibbs-MH Sampler (2)
- Bayesian Gibbs-MH (MCMC) Sampler for Spatial
Probit - Likelihood
- Diffuse Priors gt Joint Posterior
- Conditional Priors
-
-
-
-
-
52The Estimators Freq. Recursive Import. Smplr
(RIS) (1)
- Basic Idea
- To approx. n-dim. cumulative std-norm.,
- Re-express as a mean by mult divide by std
dist. truncated to support of desired integral,
(the Importance dist.) -
- This gives probability, p, sought as
- We want
- So, Imp. dist. is n-dim. MVN truncated at v.
(uh-oh! but) - V-Cov u being pos-def gt Cholesky decomposition
exists s.t.
53The Estimators Freq. Recursive Import. Smplr
(RIS) (2)
- So we want to calc. this set of indep. cum.
std.norms - Can do so recursively, beginning w/ last obs.
- First, calculate upper bound for truncated-normal
dist. of nth - Draw from this dist use it to calc upper bound
for (n-1)th - Since indep., probability of sample observed
(0,1) is product of n univariate cumulative std.
norms at these bounds, (!) - Repeat R times avg gt RIS est. of the
log-likelihood to max
54Evaluating the Estimators (One Quick MC)
- DGF (n.b., same W, diff. coeffs. For x y)
- Conditions
- Row-stdzd contig. wts U.S. 48 ?0.5, ?1.0,
n48,144,?0.0, 0.5 - You cant see this, but
- Relly poor bias perf. BG
- In fact, std ML w/ Wy
- seems dominate, but this
- b/c 2 biases, meas./spec.
- err simult. Simult incr
- in ?, meas-err decr or flat
- in n, so over- to under-est.
- (Checked its true) BV 04
- do MC like 2 for RIS find
- ?-18, ?10, so better.
55Calculating Presenting Effects (1)
- If confine discussion to y, then as prev. FH
- And s.e.s/c.i.s by delta method as
56Calculating Presenting Effects (2)
- But we (should) want to discuss
- Note given probit, must know xi given spatial
interdependence, must know X (!). - Given interdep, calc these will req. MVN cdf!
- Or better idea?
57An Example Application US State CHIP Premia
Notes 1. Informative U(0,1) prior on ? helps.
Weve qualms. 2. Difference in Bayesian vs.
frequentist significance also. 3. Note
measurement/specification-error seem to have
domd here for ML.
58Example Estimated Spatial Effect, with Certainty
Estimate, in Binary-Outcome Model
59In lieu of conclusions
- S-QualDep (latent-y) models hard, doable
- We have a lot of work yet to do
- Illustrate calculation of effects s.e.s
- Explore estimator properties systematically
- Compare non-spatial probit spatial-lag
ML-probit approximate specifications - Next Crucial Extensions
- Extend to other QualDep models
- Estimated-W models (see next for a start)
- System-of-Equations in Space
60The m-STAR Model as an Approach to Modeled,
Dynamic, Endogenous Interdependence
- Spatial Econometrics and (Political) Economy
Network Analysis and (Political) Sociology - Co-Evolution Models in Network Analysis
- (Node) Behaviors/Attributes Network (Edges)
- Spatial-Statistical Approaches to Estd-W
- A Simple Spatial-Econometric Proposal
- Estimated W Multiple W (m-STAR)
- Endogenize W means W(y)gtS-IV in m-STAR
61Spatial Econometrics
Network Analysis
- Economists Political Economists
- Core Question
- How alters actions affect egos via network
v.v.? - Contagion v. Common Exposure (Galtons Problem)
- Core Tools
- SAR, STAR, S-QualDep
- S-GMM, S-ML
- Sociologists Political Sociologists
- Core Questions
- How do nets form?
- What expl. net struct.?
- How egos position in net net struct affect?
- Core Tools
- Net stats (measures), graphics, ERGMs,
- INTERDEPENDENCE
- Definition yif(yj?i) is actions depend on
js. - Seems subset of Network Effects, which also
- Effects of structure network per se (e.g.,
transitive triplets) - Effects of position i in network per se. (e.g.,
betweenness i)
62Where Spatial Econometrics Needs to Go ( Network
Analysis is or Needs to Go also)
- Two Things Always Asked Do Next
- Qualitative Limited Dependent Variables
- Bigger estimation challenges because
- Cannot place y itself on RHS, can only place y.
- N-dimensional integration to get probabilities
- Considerable progress S-Probit/Tobit etc.,
S-MNP, S- - Estimate/Parameterize , ideally, Endogenize W
- This essence of network analysis
- However, challenges in many contexts (e.g.,
CIPE) differ - W not always (or usually) binary or categorical
- W not always (or usually) observed.
- T not always (or usually) very long.
- Temporal precedence not always (or usually)
sufficegtcausal prec.
63Leenders (1997) Co-evolution Model
- Selection
- Arc forms or not in continuous time Markov
process - Contagion
- STAR model
- gt Co-Evolution Model
- Identification strategy time lag
- Findings of MCs
- Coarse obs periodicity gt big biases
- If selection model contagion gt big biases
- If contagion model selection gt biases, less big
64Snijders (97-07) Co-evolution Model
- Steglich et al. (07) two threefold empirical
challenges - contagion, selection, context (1st3rdGaltons
Problem 2ndcoevolution gt similar implications) - In gen., any omissions or inadequacies in
modeling one tends against that favor others
looks most like it - coarse periodicity, alternative mechs paths,
net dependence precludes assume independence. - Observed Data
- N actors connected by observed, binary,
endogenous, time-variant connectivity matrix - Vector of N observed, ordinal behaviors
- Further exogenous explanators may exist at unit
or dyadic level - Model Components
- Exponential (constant hazard-rate) model of opp
to act - One change (or not) by one person _at_ one time Can
parameterize the rate Conditionally independent - When opp act, multinomial w/ N network
optionschange tie or none - Compares objective with current behaves net to
current behaves net w/ 1 switch his row
non-strategic - Can parameterize, including as function of
actions Conditionally independent - When opp act, could instead change
behavior/attribute - Compares object w/ current net behaves to his
alternative behave, w/ switch of 1,0-1 only
non-strategic - Can parameterize, including as function network
/or of others actions Conditionally
independent - Parameters to Estimate
- Coefficients of hazard-rate model and of the two
multinomial logits (n.b., IIA)
65Issues from CIPE Perspective
- Many behaviors or attributes of interest as
dependent variables, relative connectivity
between units less likely binary or ordinal. - Strengths of relative connectivity not always
observed, or even observable, directly. - Under these conditions, for estimation purposes,
the left-hand side of the selection component of
the model would have no data. Could only estimate
them off implications for behavior. - Temporal precedence often not suffice assure
causal precedence - Strategic interdep often operates literally
simultaneously or even E(future) - In estimation, simultaneous generally means
within an observational period many contexts
high frequency behavior relative to obs
periodicity. - Time lagging suffices only if insofar as
spatiotemporal dynamics fully properly
specified in model (1st non-stoch, not w/in
period simult). - Condition on 1st obs needs T large for efficiency
for small-sample bias.
66Multi-Parametric Spatio-Temporal (AR) Lag Model
67Co-Evolution Models in m-STAR Format
- Wr covariates expected explain network
- Co-evolution modelsmodels with Wf(y) larger
challenges. - Our first cut same poor mans exogeneity,
time-lag the y in Wf(y) - Our plan two-step estimation-procedure.
- First, apply spatial-GMM (see, e.g., Anselin
2006, Franzese Hays 2008b) to obtain by spatial
instrumentation consistent estimates of
endogenous wij and their estimated
variance-covariance. - Then draw from that estimated multivariate
distribution of instrumented W estimates to
insert in the conditional or unconditional m-STAR
likelihood. - Maximize likelihood under each of q draws from
that first-stage S-GMM instrumented estimated
distribution of W estimates. - Point estimates of parameters then just average
of q 2nd stage S-ML estimates - Estimated variance-covariance of
parameter-estimates is average of estimated
variance-covariance matrices from each iteration
plus (1q) times sample variance-covariance in
the point estimates across iterations (King et
al. 2001). - First stage consistent, asymptotically
efficient, so estimator should inherent nice
properties of S-ML and S-GMM, but no proof yet. - Monte Carlo assessment will follow so will
direct comparison to Snijders et al. approach
(near as two models can approx each other).
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76Conclusion
- Spatial Spatiotemporal Interdependence
- Important Appreciable Substance (e.g.,
globalization intl cap-tax compete seems quite
real does constrain), not Nuisance. - Therefore Model them. Interpret them.
- How specify estimate models?
- If space-lag is time-lagged, maybe not problem
but if thry substance says immediate (w/in an
observational period), can/should handle that
too - S-OLS not a bad strategy even then, if ? not too
big smpl-dims right S-ML, , in some regards,
IV-based strategies seem effective - Spatiotemporal Effects not directly read from
coefficients use graphs response-plots maps
grids - Info-demands Galtons Problem big, Coevolution
? REALLY big - Standard errors of effects tend big. Suspect
delta-method lin-approx. maybe part problem plan
explore performance sim/boot/jack. - Max effort care theory, measure, specification,
to both CIPE
77Thank You!