Transcript Econ 102 หลักเศรษฐศาสตร์ II
Estimation and Decomposition of Agricultural Productivity Growth in Asia
Supawat Rungsuriyawiboon Faculty of Economics Thammasat University
Introduction
“
When all people at all times have both physical and economic access to sufficient food to meet their dietary needs for a productive and healthy life
” (USAID)
F
ood crisis and food security
are back on policy agendas
Food Price Energy Price
Introduction
Some food price examples from the FAO
Type
White Thailand rice (second grade)
2003
$/ton 198
2007
$/ton 323 Yellow corn 105 160 Wheat 144 207 Powdered milk Soy oil 1,835 521 3,288 714
2008
$/ton 854 (+77%), (+62%) 250 (+58%), (+36%) 401 (+64%), (+48%) 4,750 (+61%), (+30%) 1,400 (+63%), (+49%)
Introduction
Food commodity price indices have increased across the board
52% Oil&Fat 48% Cereals 32% Dairy
Introduction
Numerous factors are influencing this price rise
Supply side:
difficult seasonal conditions in the major production regions and increased input costs.
Demand side:
increasing food demand, rising demand for grain for biofuels Given the current world food situation, it is clear from the global perspectives that each world region must have a sufficient supply in agricultural products to meet the growing food demand
Asia has the potential to supply a substantial share of the expected growth in food demand Many countries undergone from CPE to a free market economy
Introduction
Asia
has experienced impressive growth in rice and wheat production
Production of Wheat, Corn and Rice
The Green Revolution
was achieved through the application of the high-yielding varieties of major cereals and irrigation system Increased input use cannot guarantee a long-run sustainable growth rate of yields and output
Given the potential sources of factor inputs are being exhausted
, future growth in agriculture will not only rely on mobilizing inputs but will also require rising productivity Understanding the state of productivity improvements in Asia is important
Literature Review
A number of studies examine intercountry differences in productivity growth: - The availability of new panel data sets - The development of frontier analysis
Two types of frontier analysis:
Stochastic Frontier Analysis (SFA): A parametric approach - Data Envelopment Analysis (DEA): A nonparametric approach This frontier analysis allows to not only calculate productivity, but also decompose productivity growth Both SFA and DEA models conducted in many studies
investigate intercountry productivity growth in Asia differences in agricultural
using the panel data from the FAO
to
Literature Review
A nonparametric DEA model:
- Bureau, Färe, and Grosskopf (1995) - Fulginiti and Perrin (1997) - Arnade (1998) - Suhariyanto and Thirtle (2001) - Trueblood and Coggins (2003) - Coelli and Rao (2005)
A parametric SFA model:
- Fulginiti and Perrin (1993) - Craig, Pardey and Roseboom (1997) - Wiebe et al (2000) - Liu and Wang (2005) Because of data problems of transition countries in Central Asia,
previous studies just ignored these countries
Objectives
First, this study formulates a general model using a parametric technique to measure productivity growth
This approach allows to uncover what sources attributing to productivity growth.
Second, this study measures productivity growth in Asian countries
This study includes 27 countries for 25 years. The size of this sample allows us to examine productivity for almost all major nations in Asia over time.
Theoretical Framework
Performance of a firm A study about an ability of a firm to convert inputs into outputs given a technology in the production process Performance measurement is a relative concept A simple measure of performance is a
productivity ratio
Productivity
is defined as the ratio of outputs to inputs
Productivity
=
outputs inputs
The greater value implies the better performance
Productivity Measurement
If a production technology consists of
multiple inputs and outputs
, a measure of productivity becomes more complex Productivity measured from the multi-input and multi-output production technology is called
total factor productivity (TFP)
TFP can be measured using a concept of
index number
TFP index
=
output index input index
Other Method to Measure Firm’s Performance
Another method to measure the performance of a firm is to use a concept of firm’s
efficiency
In practice, the terms,
productivity and efficiency have been used interchangeably
. However, they are not precisely the same things.
Efficiency of a firm
is measured using
a production frontier.
A Measure of Technical Efficiency
Consider a simple production process in which a single input (x) is used to produce a single output (y) Line OF’ represents the maximum output attainable from each input level.
The line OF’ is called a production frontier
Consider three firms, that is A, B and C, are operating as follows • Firm A is operating beneath the frontier OF’ whereas firm B and C are operating on the frontier OF’ • Firm B and C are
efficient technically
• Firm A is
technically inefficient
•
Technical efficiency (TE)
measured by the distance. TE is equal to
0A/0B
or
0C/0A
can be
Distinction between Technical Efficiency and Productivity
From the figure, firm A is
technically inefficient
whereas firm B and C are
technically efficient
Productivity of these firms are measured by the slope of the rays from origin
Firm C has higher productivity than firm A and B.
Firm C has the highest productivity
Point C is the point technically optimal scale.
Operation at any other point on the production frontier results in lower productivity. Point C indicates an operation at
of scale economies
Distance function
Consider a production technology when used to produce
multiple outputs multiple inputs
are
Production frontier
technology can not use to describe this production Shephard (1953, 1970) proposes
a distance function
describe the structure of production technology with inputs and outputs to multiple
Two types of distance function
1. Input distance function, D I 2. Output distance function, D o
Output Distance Function (D
o
)
The minimum amount by which an output vector can be deflated and still remain producible with a given input vector.
Output distance function D o (x,y)
D o min : is defined as y P
where P(x) = {y: (y,x) Є T}
Consider M = 2
This figure shows that the output vector y is producible with input x, but so is the radially expanded output vector (y/μ*)
B So, D 0 (x,y) = μ * = OA/OB ≤ 1 A D 0 (x,y) = TE 0
Properties of Output Distance Function
(i) D o (x, 0) = 0 and D o (0, y) = ∞ (ii) D o (x, λy) = λD o (x, y) for λ > 0
(HOD+1 in y)
(iii) D o (λx, y) ≤ D o (x, y) for λ ≥ 1
(non-increasing in x)
(iv) D o (x, λy) ≤ D o (x, y) for 0 ≤ λ ≤ 1
(non-decreasing in y)
(v) D o (x, y) is convex function in y
Methodology
Total Factor Productivity (TFP) growth:
not explained by growth in input uses Residual growth in outputs
Färe et al. (1989)
proposed a
Malmquist TFP index
productivity growth using the
output distance function
to measure The
output distance function
D o t
X t
,
Y t
min at period t :
X t
,
Y t
T t
represents the minimum amount by which y t remain producible with x t can be deflated and still
Methodology
The
Malmquist TFP index
M o t ( x t 1 , in period
t
y t 1 , x t , y t ) D o t ( x t 1 , y t 1 ) D o t ( x t , y t ) The
Malmquist TFP growth index
between
t
and
t
+ 1 M o ( x t 1 , y t 1 , x t , y t ) D o t D t ( o x t 1 ( x t , , y t 1 ) y t ) t 1 D ( o D o t 1 x t ( x 1 t , , y t 1 ) y t ) 1 / 2
Period t Period t+1 Malmquist TFP growth (MTC) Technical Efficiency Change (TEC) Technical Change (TC) Scale Efficiency Change (SEC)
TFP growth decomposition
Methodology
Orea (2002) employs a parametric technique to derive a generalized MPC decomposition.
The
output distance function
taking the Translog functional form ln
D o it
( ) 0
m M
1
y m
ln
Y mit
1 2
m M M
1 1
y m y m
ln
Y mit
ln
Y mit
k K
1
x k
ln
X kit
1 2
k K K
1 1
x k x l
ln
X kit
ln
X lit
k K M
1 1
x k y m
ln
X kit
ln
Y mit
t t
1 2
tt t
2
k K
1
x k t
ln
X kit
t
m M
1
y m t
ln
Y mit
t
Young’s theorem requires
linear homogeneity in outputs
M m 1 y m 1 , n M 1 y m y n 0 , M m 1 x k y m 0 , M m 1 y m t 0 ln
Y Mit
0
M
m
1 1
y m k K M
1 1
m
1
x k y m
ln
Y
*
mit
ln 1 2
M m
1
M
1
X kit
ln
Y
*
mit n
1 1
z t
y m y m
ln
Y
*
mit
1 2
tt t
2 ln
Y
*
mit k K
1
x k t
ln
k K
1
x k X kit
t
ln
X kit M
m
1 1
y m t
1 2
k K K
ln
Y
*
mit
t
x k
ln
x l
ln
D o it X kit
ln
X lit
Methodology
The decomposition of MTC can be calculated as
Technical Efficiency Change (TEC) Technical Change (TC) Scale Efficiency Change (SEC)
ln ln
D t o
1
D t o
1 2 ln
D t o
1
t
( ) ln
D t o
t
( ) 1 2
k K
1
K k
1
e kt
1 1
s kt
1
k K
1
e kt
1
s kt
ln ln
X kt
1
X kt
Data
The empirical analysis in this study focuses on agricultural production of
27 Asian countries
over the period from
1980-2004
The primary source of data is obtained from the website of the
and Agricultural Organization (FAO)
AGROSTAT system
Food
acquired from the Production technology consists of
input variables two output variables
and
five
Data
Output Variables:
The output series are derived by aggregating detailed output quantity data on
115 cropping commodities and 12 livestock commodities
expressed in terms of the international average prices (in US dollars)
Input Variables:
Land: Arable land in hectare includes both land under permanent crops as well as the area under permanent pasture Tractor: the total number of wheeled- and crawler tractors used in agriculture Labor: the number of economically active people in agriculture Fertilizer: the commercial use of nitrogen, potassium and phosphate fertilizers in nutrient-equivalent terms expressed in thousands of metric tons Livestock: the sheep-equivalent of the six categories of animals (buffaloes, cattle, pigs, sheep, goats and poultry)
Country Profile
Region Central Asia (CA) East Asia (EA) West Asia (WA) Southeast Asia (SEA) South Asia (SA) Country Kazakhstan (KAZ) Kyrgyzstan (KGZ) Tajikistan (TKM) Turkmenistan (TJK) Uzbekistan (UZB) China (CHN) Japan (JPN) Republic of Korea (PRK) Mongolia (MNG) Iraq (IRQ) Israel (ISR) Saudi Arabia (SAU) Syrian Arab Republi (SYR) Cambodia (KHM) Indonesia (IDN) Lao PDR (LAO) Malaysia (MYS) Myanmar (MMR) Philippines (PHL) Thailand (THA) Vietnam (VNM) Bangladesh (BGD) India (IND) Islamic Rep of Iran (IRN) Nepal (NPL) Pakistan (PAK) Sri Lanka (LKA)
Estimated Parameters of the Output Distance Model Parameter a
β
0
β
y1 (crop)
β
x1 (land)
β
x2 (tractor)
β
x3
β
x4 (labor) (fertilizer)
β
x5 (livestock)
β y
1
y
1
β x
1
x
1
β x
2
x
2
β x
3
x
3
β x
4
x
4
β x
5
x
5
β x
1
x
2
β x
1
x
3
β x
1
x
4
β x
1
x
5
β x
2
x
3
β x
2
x
4
β x
2
x
5
β x
3
x
4
β x
3
x
5
β x
4
x
5
β x
1
y
1
β x
4
y
1
β x
5
y
1
β t β tt β x
1
t β x
5
t β y
1
t
Estimates
0.277
0.490
-0.099
-0.184
-0.192
-0.224
-0.334
0.331
-0.101
0.033
0.151
-0.022
-0.228
0.043
-0.103
0.048
0.035
0.195
-0.060
-0.128
-0.214
-0.008
0.296
-0.051
0.189
0.114
-0.008
-0.001
-0.008
-0.006
-0.001
t-Statistic
8.781**
20.114
**
-7.126
**
-15.228
**
-8.222
**
-16.310
**
-11.067
** 5.253** -7.517** 3.321* 2.455* -3.161** -2.034
5.147** -4.426
5.470** 1.179
8.454** -7.818** -4.866** -10.331** -0.103
12.564** -2.115* 10.061** 2.067* -6.887** -2.590* -6.996** -2.564* -0.410
MTC and Decomposition for All Asian Countries Region Asia Period
1980-1985 1985-1990 1990-1995 1995-2000 2000-2004
1980-2004 TEC
-0.598
0.371
-0.218
-0.885
0.835
-0.138
TC
1.422
1.897
2.376
2.847
3.245
2.321
SEC
-0.481
-0.494
-0.300
0.061
-0.165
-0.280
MTC
0.343
1.775
1.857
2.023
3.916
1.902
TFP growth across all of Asia was positive and nearly 2% The high TFP growth has relied on TC.
The high TFP growth for Asia is largely driven by rises in TFP during the past 5 years.
TFP growth has been pulled down due to declining TEC and SEC. This decline may be due to the continued rise in off-farm employment. Asian TFP growth was relatively robust and rising. This is good news for those concerned about keeping balance in Asia and world food markets.
MTC and Decomposition for Each Region (in %) Region A) SA B) SEA C) WA D) EA E) CA Period 1980-2004 1980-2004 1980-2004 1980-2004 1992-2004 TEC -0.176
0.292
-0.402
-0.218
-0.087
TC 2.456
0.825
0.081
2.739
1.940
SEC -0.064
-0.050
-0.056
-0.495
-0.509
MTC 2.216
1.066
-0.376
2.026
1.344
SA and EA exhibited high TFP growth. TC was a major factor driving TFP growth. TFP growth would have been higher had efficiency levels not fallen TFP growth rate in SEA was only 1.1%. Both TEC and TC contributed to TFP growth in SEA. WA was the only region exhibiting TFP regress. However, average TFP growth is small. Both TEC and SEC dragged down TFP growth.
Without including transition countries in CA,
TFP growth rate in CA reached 1.4%. Asian TFP growth would have been lower.
MTC and Decomposition by Transition Countries (in %) Transition Country A) China B) Mongolia C) Vietnam D) Laos E) Myanmar F) Kazakhstan G) Kyrgyzstan H) Tajikistan I) Turkmenistan J) Uzbekistan Periods 1980-2004 1991-2004 1986-2004 1986-2004 1989-2004 1992-2004 1992-2004 1992-2004 1992-2004 1992-2004 TEC -0.250
0.078
-0.062
-1.320
0.008
0.225
-0.219
0.517
0.069
-0.950
TC 3.209
3.983
0.052
0.542
1.704
3.412
0.587
0.232
1.529
1.215
SEC -0.358
-0.347
-0.734
0.544
0.545
-1.689
-1.020
0.268
0.687
0.122
MTC 2.600
3.714
-0.744
-0.234
2.256
1.948
-0.653
1.018
2.285
0.387
Conclusion
With nearly half of the potential agricultural resources, Asia has the potential to supply an increase in world food demand By including more member countries into the analysis especially the transition economies,
Asian countries exhibited a healthy TFP growth with a growth rate of 1.9 per annum.
Investments in R&D was a major contribution to TFP growth in Asian agriculture
The healthy TFP growth in Asian agriculture
enhanced by countries in EA and SA.
is greatly
Focusing on transition countries,
terms of the magnitude and direction of agricultural TFP growth during the past two decades. large differences exist in Some transition countries such as
Turkmenistan China, Mongolia and
exhibited above average growth. Others, such as,
Kyrgyzstan, Uzbekistan, Laos, and Vietnam
did not do so well