Economics Letters 195 (2020) 109402
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Economics Letters
journal homepage: www.elsevier.com/locate/ecolet
Quantile selection in non-linear GMM quantile models
Luciano de Castro
a,d
, Antonio F. Galvao
b,∗
, Gabriel Montes-Rojas
c
a
University of Iowa, Iowa City, USA
b
University of Arizona, Tucson, USA
c
Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
d
IMPA, Rio de Janeiro, Brazil
article info
Article history:
Received 31 March 2020
Received in revised form 2 June 2020
Accepted 7 July 2020
Available online 16 July 2020
JEL classification:
C31
C32
C36
E21
Keywords:
Quantile regression
Instrumental variables
Quantile preferences
Elasticity of intertemporal substitution
Risk attitude
abstract
This note proposes a non-linear GMM quantile regression model to estimate the quantile as an
additional parameter. The limiting distribution is studied. An empirical application to an intertemporal
consumption model built on a structural dynamic quantile utility model illustrates the estimator. Using
US data, it separately estimates the elasticity of intertemporal substitution and the risk attitude, which
is captured by the estimated quantile.
© 2020 Elsevier B.V. All rights reserved.
1. Introduction
Since the seminal work of Koenker and Bassett (1978), quan-
tile regression (QR) has attracted considerable interest in statis-
tics and econometrics. QR estimates conditional quantile func-
tions that provide insight into heterogeneous effects of variables
of interest, indexed by the quantiles, τ ∈ (0, 1). Chernozhukov
and Hansen (2005, 2006, 2008) extend QR methods and present
results on identification, estimation, and inference for an instru-
mental variables QR (IVQR) model that allows for endogenous
regressors; see Chernozhukov et al. (2017) for an overview of
IVQR. Kaplan and Sun (2017) and de Castro et al. (2019) de-
velop estimators for QR models with instruments in a generalized
method of moments (GMM) framework. In general, investigating
the entire quantile process is of interest because one may be in-
terested in either testing global hypotheses about conditional dis-
tributions or making comparisons across different quantiles (for
a discussion about inference in QR models see Koenker and Xiao,
2002). Nevertheless, in an attempt to provide the ‘most repre-
sentative quantile’, Bera et al. (2016) consider a QR model within
∗
Corresponding author.
E-mail addresses: luciano@impa.br (L. de Castro),
agalvao@email.arizona.edu (A.F. Galvao), gabriel.montes@fce.uba.ar
(G. Montes-Rojas).
a quasi-maximum likelihood asymmetric Laplace framework and
propose methods to estimate the quantile together with the pa-
rameters of interest.
1
The estimated quantile captures a measure
of asymmetry of the distribution of innovations, and it does not
necessarily lead to the mode, but to a point estimate that is most
probable, in the sense it maximizes the entropy.
Recently, quantile preferences (QP) have attracted attention
in modeling economic behavior in dynamic frameworks.
2
QP
are an alternative to expected utility models with useful ad-
vantages, such as, in dynamic models, allowing the separation
between risk aversion and elasticity of intertemporal substitution
(EIS), the ability to capture heterogeneity by offering a family
of preferences indexed by the quantile index, τ ∈ (0, 1), dy-
namic consistency and monotonicity. Giovannetti (2013) presents
a two-period standard economy with one risky and one risk-free
asset, where the agent has QP instead of the standard expected
utility. de Castro and Galvao (2019a) develop a dynamic model
of rational behavior under uncertainty, in which the agent max-
imizes the stream of the future quantile utilities, and derive the
1
See also Machado (1993) and Koenker and Machado (1999) where the
quantile appears naturally as a location parameter and the pioneering work
of Yu and Moyeed (2001) and Yu and Zhang (2005).
2
Manski (1988) introduced QP, which have been subsequently axiomatized
by Chambers (2009), Rostek (2010), and de Castro and Galvao (2019b).
https://doi.org/10.1016/j.econlet.2020.109402
0165-1765/© 2020 Elsevier B.V. All rights reserved.