
of registered imports that determines which of the two rates applies to each import incident. To determine
the timing of the cumulative volume exceeding the annually scheduled quotas, we utilize monthly data on
import incidents in all cases. Under a GPS, tariffs are levied to hold the post-tariff price at a constant level
for all import incidents with pretax prices lower than the gate price. From another perspective, the applied
tariff duties under TRQ and GPS depend on volumes and pretax prices of import incidents, and hence, they
must be correlated with import demand and hence with import demand shocks. We must therefore rule
tariffs out as a potential instrument.
Consequently, we utilize exchange rates to instrument for the endogenous explanatory variable, i.e., the
post-tariff price, in the first-stage regression under the assumption that exchange rates and meat import
demand shocks are independent. Our instrument is sufficiently relevant in all cases. The first-stage regression
is based on a multi-input CES function where the elasticity of substitution (microelasticity) can be estimated
via fixed effects (FE) estimation based on our country-level import observations in time series. Additionally,
by using time dummy variables, we are able to retrieve the first-stage aggregates from the dummy coefficients
and the microelasticity. Since the estimates of the first-stage aggregates do not contain (the estimates of) the
demand shocks, we are able to apply them as an instrument to address the endogeneity in the second-stage
regression, where the error term may contain the first-stage demand shocks. In this way, the second-stage
elasticity of substitution (macroelasticity) is estimated.
The remainder of this paper proceeds as follows. In the following section, we introduce the two-stage
CES aggregation model, deriving two (first- and second-stage) regression equations for estimating the mi-
croelasticity and the macroelasticity. While the microelasticity and first-stage aggregates are estimated by
the first-stage regression, the second-stage regression utilizes the first-stage aggregates and estimates the
macroelasticity. In Section 3, we present how we prepare the data for the abovementioned regression analy-
ses. All applied tariff rates are calculated according to the tariff scheme applied for meat imports to Japan,
which we summarize in the Appendix. Our main results are presented in Section 4, where we show the
final estimates of microelasticities and macroelasticities for beef, chicken, and pork. Section 5 concludes the
paper.
2. Model
2.1. Two-stage CES aggregation
Consider, for some commodity m(index suppressed), a two-stage Armington aggregator as follows:
u=β1
ρzρ−1
ρ+ (1 −β)1
ρyρ−1
ρρ
ρ−1y=
N
X
i=1
(αi)
1
σ(xi)σ−1
σ
σ
σ−1
where xidenotes the quantity (of commodity m) imported from country i,ydenotes the utility of ag-
gregated imports, zdenotes the quantity produced and consumed in the home country, and udenotes the
representative utility in the home country. Regarding the parameters, σdenotes the elasticity of substitution
among imports from different countries (or microelasticity), ρdenotes the elasticity of substitution between
domestic and aggregate imports (or macroelasticity), and αi≥0and β≥0are the preference parameters
with PN
i=1 αi= 1 and β≤1. The first function (on the right) is called the first-stage aggregator, and the
second (on the left) is called the second-stage aggregator.
The dual function of this two-stage Armington aggregator can be written as follows:
v=βr1−ρ+ (1 −β)q1−ρ
1
1−ρq=
N
X
i=1
αi(pi)1−σ
1
1−σ
(1)
where pidenotes the (tariff-inclusive) import commodity price from country iin the home country. Note that
the price of the commodity from the ith country pi(JPY/kg) in terms of Japan’s currency unit, domestic
2