Estimating Technical Efficiency of Crude Palm Oil in Malaysia
Mariah Binti Sabar
1
and Anton Abdulbasah Kamil
2
1
School of Mathematical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia
2
Faculty of Economics, Administrative and Social Sciences, Istanbul Gelisim University, Istanbul, Turkey
Keywords:
SFA, TE, Cobb-Douglas Functional Form, Translog Functional Form, CPO.
Abstract:
The main purpose of this study is to apply parametric techniques in evaluating the technical efficiency (TE) of
crude palm oil (CPO) production by the states in Malaysia. To achieve this, the parametric stochastic frontier
analysis (SFA) approach was applied. This study involves a panel data consisting of 12 CPO producing states
in Malaysia, over a 18 year time period from year 1999 to 2016. The output variable chosen was the annual
CPO production and the input variables considered were plantation area, fruit mill capacity, labour and time
variable. We found fruit mill capacity, labour and time as input variables that significantly affect the level of
CPO output. Plantation area was proven to be statistically insignificant. Technical efficiency was found to be
increasing over time. It was also found that the inefficiencies in the industry were mainly caused by ‘pure’
technical inefficiency rather than scale inefficiency. The overall mean TE of SFA is 0.79. Selangor is the top
efficient state according to SFA. We concluded that the state of Malacca is overall the least efficient state due
to their low ranking.
1 INTRODUCTION
Malaysia is one of the biggest palm oil producers
in the world (Basiron, 2007). The country accounts
for 44% of the world’s exports of palm oil making
the industry the fourth major revenue for the nation
(M.P.C., 2014). The industry plays a huge role in the
development of the country by reducing poverty rate
from 50% in the 1960s, to less than 5% today. The
success of the Malaysian palm oil industry, however,
did not come without a price. From health campaign
claiming the oil increased risk of heart diseases, al-
leged land grabs, deforestation and the extinction of
the orang utan to the recent resolution by the Euro-
pean Parliament calling for the EU to phase out the
use of palm oil in biodiesel that are allegedly pro-
duced in an unsustainable way, leading to deforesta-
tion.
With the continuous pressure and controversies
surrounding the manufacturing of palm oil, it is only
ideal that the Malaysian palm oil industry demon-
strate sustainability by being more efficient in the us-
age of resources. Measuring efficiency is important
not only to have a reliable record of the industry’s
progress, but also to be able to investigate the im-
pact of any new and already existing implemented
policies. Methods for estimating efficiency can be
categorized into two, parametric approach and non-
parametric approach. These approaches can either
be deterministic or stochastic (Bogetoft et al., 2011).
Among the various methods developed, parametric
stochastic frontier analysis (SFA) is the most com-
monly used technique for estimating technical effi-
ciency (Baten et al., 2009), (Hassan et al., 2012). The
SFA technique involve mathematical programming
and econometric methods, respectively (Coelli et al.,
2005). To our knowledge, no study has yet used the
most applied parametric SFA technique to find the ef-
ficiency of producing CPO by the states in Malaysia.
The result could be an indicator to where each state
stands in terms of producing CPO efficiently among
the states in Malaysia. This can serve as a planning
aid for management and policy makers to draw con-
clusion on existing and new regulations.
2 METHODOLOGY
Efficiency Measurement According to (Farrell, 1957),
the efficiency of a firm could be looked at from two
components; technical efficiency and allocative effi-
ciency. Technical efficiency is the ability of a firm to
produce the maximum amount of output from a given
set of inputs. Meanwhile, allocative efficiency repre-
198
Sabar, M. and Kamil, A.
Estimating Technical Efficiency of Crude Palm Oil in Malaysia.
DOI: 10.5220/0012446800003848
Paper published under CC license (CC BY-NC-ND 4.0)
In Proceedings of the 3rd International Conference on Advanced Information Scientific Development (ICAISD 2023), pages 198-203
ISBN: 978-989-758-678-1
Proceedings Copyright © 2024 by SCITEPRESS – Science and Technology Publications, Lda.
sents the firm’s ability to use the optimal proportions
of inputs given their respective prices and the produc-
tion technology. This study focuses on technical effi-
ciency (TE).
The following notations are used: i, j = 1,...,N
the collection of decision making units (DMU), t =
1,...,T study period, k,l = 1, ...,K number of inputs.
2.1 Theoretical Stochastic Frontier
Model
The model used was the production model for panel
data proposed by (Battese and Coelli, 1992) ex-
pressed as:
lnyit = X
it
β + (v
it
u
it
, (1)
u
it
= u
i
exp η[(t T ],i = 1,..., N,t = 1, ...,T (2)
where y
it
is the output of the i-th unit in the t th
time period, x
it
is a (K x 1) vector of transformation
of the input quantities of the i th unit in the t th
time period, β is a vector of unknown parameters to
be estimated, v
it
are random variables assumed to be
independent and identically distributed N(0,σ
2
v
) and
are independent of u
it
, η is a unknown parameter to
be estimated and u
i
are non-negative random variables
which are assumed to be independent and identically
distributed as truncations at zero of the N(0,σ
2
v
) dis-
tribution and are assumed to represent the technical
inefficiency in production.
The inefficiency model (2) can be in the form of a
truncated normal distribution, half normal distribution
or an exponential distribution (Hossain, 2013). How-
ever, in this study only the truncated normal or half-
normal distributions were considered. (Battese and
Corra, 1977) parameterized σv
2
and σ
2
u
by replacing
them with:
σ
2
= σ
2
v
+ σ
2
u
(3)
γ = σ
2
u
/σ
2
(4)
Gamma (γ) is an unknown parameter that lies be-
tween zero and one. It explains the presence of the
inefficiency component in the total error term (Coelli
et al., 2005). The technical efficiency (TE) of the
i th unit at the t th time period can be measured
by:
T E
it
= y
it
/y
it
= exp(x
it
β + v
it
u
it
)/exp(x
it
β + v
it
)
= exp(u
it
)
(5)
where y
it
is the observed output and yit is the cor-
responding stochastic frontier output.
The measurement of technical efficiency is the ob-
served output of a unit relative to the output that po-
tentially could be produced by a fully-efficient unit
using the same amount of input (Coelli et al., 2005).
The value can range between zero and one.
2.1.1 Application
Empirical Stochastic Frontier Model After the out-
put and input variables involved were made clear, the
functional form of translog production model (Battese
and Coelli, 1992) was applied that can be defined as:
lnCPO
it
= β
0
+ β
1
lnArea
it
+ β
2
lnMC
it
+β
3
lnLabour
it
+ β
4
t + 1/2[β
11
(lnArea
it
)
2
+
β
22
(lnMC
it
)
2
+ β
33
(lnLabour
it
)
2
+ β
44
t
2
+β
12
lnArea
it
lnMC
it
+ β
13
lnArea
it
lnLabour
it
+ β
14
lnArea
it
t +β
23
lnMC
it
lnLabour
it
+ β
24
lnMC
it
t
+β
3
4lnLabour
it
t +v
it
u
it
(6)
where i = 1, 2, ..., 12 and t = 1, 2, ..., 18,
ln refers to the natural logarithm, CPO
it
is the
amount of crude palm oil production by the ith state
at t th period,
Area
it
is the area under oil palm plantation in the ith
state at t th period,
MC
it
denotes the total fruit mill capacity available in
the i th state at t th period,
Labour
it
is the number of plantation employee work-
ing in the i th state at the t th period, t is the study
period from the value of 1 to 18 (year 1999 to 2016),
β, v
it
and uit are as defined in the previous section.
The most used functional forms are the Cobb-
Douglas model and the transcendental logarithmic
(trans-log) model. According to (Ferdushi, 2013),
choosing the most appropriate model for our analysis
is crucial as the functional form would significantly
affect our results. Hence, to test whether the trans-log
model above is the appropriate functional form for our
model, the likelihood ratio test was conducted which
would be explained in the next section. The time vari-
able in the stochastic frontier model (6) was included
to allow for Hicksian neutral technological change
(Baten et al., 2009), while in the inefficiency model
(2) the time variable is associated with the change
in inefficiency as the time period increases (Coelli
and Battese, 1996a). In model (6), the time-squared
and the time interaction with each (log) input variable
Estimating Technical Efficiency of Crude Palm Oil in Malaysia
199
were considered to allow for non-monotonic technical
change and non-neutral technical change respectively
(See and Coelli, 2012). Hypothesis Test Several hy-
potheses would be tested to verify the validity of the
results, to find the most appropriate functional form
for the model and to select the distribution of the ran-
dom variables assumed to represent the technical in-
efficiency (Ferdushi et al., 2011), (Mustapha, 2011).
There are many different combinations and alterna-
tive models types to choose from. For the stochastic
frontier model, the most common used are the Cobb-
Douglas model or the trans-log model. For the ineffi-
ciency model, one can assume whether the inefficien-
cies follow a half-normal distribution or a truncated
normal distribution. Since our data is a panel data, we
also had to decide whether to assume time-varying or
time invariant efficiencies. To solve this problem, a
number of alternative models were estimated and then
the likelihood ratio tests were carried out to select the
most appropriate model (Coelli and Battese, 1996a).
We would be testing 4 hypotheses:
1. H
0
: γ = 0, testing the significance of the γ param-
eter is basically testing whether it is necessary to
apply the stochastic frontier production function.
From equation (4), we could see that if the null
hypothesis is true, then the value of σ
2
u
would also
be equal to zero meaning there is no technical in-
efficiency present. Thus, the uit term should be
removed, turning the model into an ordinary lin-
ear regression model that could be solved using
the ordinary least squares (OLS) method.
2. H
0
: β
k
l = 0(k l = 1,2,3,4), the null hypothesis
specifies that the coefficients of the squared
input and the interaction between input variables
of the stochastic frontier function are simulta-
neously zero. This means that the parameters
β
11
,β
22
,β
33
,β
44
,β
12
,β
13
,β
14
,β
23
,β
24
,andβ
34
are restricted to the value of zero. If this is
accepted, then the Cobb-Douglas functional form
is more appropriate than the translog functional
form.
3. H
0
: µ = 0, this particular hypothesis is to test
whether the distribution for the inefficiency is a
half-normal distribution or a truncated normal dis-
tribution. The null hypothesis implies that the
mean of the inefficiency distribution is equal to
zero, making it a half-normal distribution which
is a special case of the truncated normal distribu-
tion.
4. H
0
: η = 0, implies that the technical inefficiencies
are time invariant.
As we can see from equation (2), if the null hy-
pothesis η = 0 is accepted then it would mean that
the technical inefficiencies are not affected by time.
All of these hypotheses were tested using the like-
lihood ratio test. The generalized likelihood ratio
(LR) test statistic is defined by:
LR = 2ln [L(H
0
)/L(H
1
)]
= 2ln [L(H
0
)] ln [/L(H
1
)]
(7)
where ln[L(H
0
)] and ln [L(H
1
)] are the values of
the log-likelihood function of the production frontier
model under the null and the alternative hypotheses
respectively. Under the null hypothesis, the LR statis-
tic is assumed to be a Chi-square (or a mixed Chi-
square) distribution with the degree of freedom equal
to the number of restrictions involved (Coelli and Bat-
tese, 1996b). If the value of the LR test statistic ex-
ceeds the critical value, then the null hypothesis is re-
jected (Taymaz and Saatci, 1997).
3 RESULTS AND DISCUSSION
3.1 Maximum Likelihood Estimates of
the Translog Stochastic Frontier
Production Function
The maximum likelihood estimates for the parame-
ters of the translog crude palm oil production model
is shown in Table 1.
Table 1: Maximum likelihood estimates for the parameters
of the translog production function.
Variable Parameter Coefficient Standard Error t-ratio
Constant β
0
19.21489*** 3.11286 6.17274
Area β
1
-0.00817 1.23538 -0.00661
MC β
2
-2.83437*** 1.02815 -2.75677
Labour β
3
1.49079** 0.59092 2.52283
t β
3
0.18653*** 0.04569 4.08262
... ... ... ... ...
Variance Pa-
rameter
Sigma-
Squared
σ
2
0.05309** 0.02437 2.17910
Gamma γ 0.71642*** 0.12953 5.53094
Eta η 0.04956*** 0.01445 3.42982
Looking at the maximum likelihood estimates of
the coefficient of the first order variables, it is clear
that all the variables except plantation area signifi-
cantly affect the level of crude palm oil production.
Fruit mill capacity and time both yield coefficient that
are highly statistically significant at 1% level of sig-
nificance. The coefficient of time is estimated to be
0.187 meaning that as time increases by a year, then
crude palm oil production would increase by 0.187
tonnes if the effects of all other predictors are held
ICAISD 2023 - International Conference on Advanced Information Scientific Development
200
constant. It also implies that technical progress in-
creases on average of 18.7% per year. Meanwhile,
the coefficient of fruit mill capacity is - 48 2.834. The
negative sign of the coefficient could possibly indi-
cate that the current existing mills are not fully uti-
lized to their full capacity. This could also suggest
that smaller size fruit mills are more productive com-
pared to the larger fruit mills because they are easier
to manage and monitor. Labour yield a significant
coefficient at 1.491 implying that the labour variable
influences crude palm oil output positively. The value
of the coefficient for plantation area is approximated
at -0.008.
However, this value is proven to be statistically in-
significant implying that plantation area does not af-
fect the output level significantly. All of the second
order variables are found to be insignificant. The co-
efficients of the product variables between plantation
area with fruit mill capacity, fruit mill capacity with
time and labour with time appear to be significant at
the 10% level of significance. The other interactions
between input variables were found to be insignificant
to production.
The parameter of error σ
2
is estimated to be 0.053
with significance level at 5%. Since σ
2
is statistically
significantly different from zero, we can say that the
model is a good fit to our data set. The parameters γ
and η are found to be significant at 1% level of signif-
icance. γ is estimated at 0.716, implying that 71.6%
of the variation in deviation is caused by technical in-
efficiency whereas 28.4% is caused by the stochastic
random error. This result shows that technical ineffi-
ciency is important in explaining the total variability
within the production of crude palm oil. The param-
eter η is approximated to be 0.05. The positive value
of η suggests that the technical inefficiency tends to
decline over time. Thus, the technical efficiency in-
creases over time.
3.2 Estimated Technical Efficiency of
Production
Table 2 displays the readings of the estimated tech-
nical efficiency for the production of crude palm oil
of each state for each year generated. The overall
mean technical efficiency in the production of crude
palm oil for the states in Malaysia from the year 1999
to 2016 is 0.792. This means that 79.2% of the po-
tential output is achieved by the palm oil industry in
Malaysia. However, this also shows that there exists
technical inefficiency of around 20.8% that can be im-
proved using the same amount of existing resources.
The lowest reading of technical efficiency is 0.4 by the
state of Malacca during 1999. On the other hand, the
highest reading is 0.986 by Selangor in 2016. None
of the states got 100% level in efficiency at any given
year.
Table 2: Estimated technical efficiency of producing crude
palm oil for the states in Malaysia from 1999 to 2016 by
stochastic frontier analysis.
State 1999 2000 2001 ... 2016 Mean
Selangor 0.968 0.970 0.971 ... 0.986 0.978
Sarawak 0.931 0.934 0.937 ... 0.969 0.952
Perak 0.892 0.897 0.902 ... 0.952 0.926
N. Sembilan 0.891 0.896 0.901 ... 0.951 0.925
Penang 0.759 0.770 0.779 ... 0.888 0.831
Terengganu 0.726 0.737 0.748 ... 0.871 0.806
Kedah 0.712 0.724 0.735 ... 0.864 0.795
Sabah 0.590 0.606 0.620 ... 0.797 0.702
Johor 0.581 0.596 0.612 ... 0.791 0.695
Kelantan 0.554 0.570 0.586 ... 0.775 0.674
Pahang 0.554 0.570 0.586 ... 0.775 0.673
Malacca 0.400 0.418 0.436 ... 0.674 0.544
It was found that out of the 12 states, 7 states
yielded mean technical efficiency above the overall
average of 0.792. The most efficient state is the state
of Selangor with a mean efficiency at 0.978. This im-
plies that among all the states, Selangor is the most
efficient in managing its resources to maximize pro-
duction. It is clear that the least efficient state is
the state of Malacca with mean efficiency reading of
0.544. The difference in score of the mean techni-
cal efficiency of Selangor and Malacca is a staggering
0.434. Meanwhile, the largest state in Malaysia, the
state of Sarawak rank second with a yield mean ef-
ficiency score of 0.952. This is followed by Perak,
Negeri Sembilan, Penang, Terengganu and Kedah
with scores of 0.926, 0.925, 0.831, 0.806 and 0.795
respectively. The state of Sabah, which is the largest
producer of crude palm oil between the states, ranked
eighth following a mean efficiency score of 0.702.
This indicates that Sabah can improve their output
level by around 29.8% by fully utilizing their current
available resources. After Sabah, the state of Johor,
Kelantan and Pahang follow closely at 0.695, 0.674
and 0.673 respectively.
3.3 Selection of the Production
Function and Hypotheses Testing
To determine the form of the production function,
several hypothesis tests were carried out. The results
are shown in Table 3:
According to (Coelli, 1995), if the null hypoth-
esis involves γ = 0, then the asymptotic distribution
requires a mixed Chi-square distribution. Thus, the
critical value for the first null hypothesis is obtained
from Table 1 of (Kodde and Palm, 1986). The null
hypothesis is rejected since the value of the test statis-
Estimating Technical Efficiency of Crude Palm Oil in Malaysia
201
Table 3: Generalized likelihood ratio test of hypothesis for
the stochastic frontier production model.
Null L-
likelihood
L-
likelihood
LR
test
Critical Decision
Hypothesis Function
(H
0
)
Function
(H
1
)
Statistic Value
H
0
: γ =
0
87.1588 120.3780 66.4383 2.706* Reject
H
0
:
β
kl
= 0
70.7475 125.4358 109.3765 18.307 Reject
H
0
: µ =
0
125.3437 125.4358 0.1842 3.841 Accept
H
0
: η =
0
120.3780 125.3437 9.9314 3.841 Accept
tic exceeds the critical value. This result confirms that
technical inefficiencies exist and are significant in ex-
plaining the performance in the production of crude
palm oil by the states. The second null hypothesis
H0 : βkl = 0 which specifies that the Cobb-Douglas
production function is statistically more preferable
than the translog production function is rejected. This
indicates that the usage of translog production func-
tion is more appropriate for the data set. The third null
hypothesis H
0
: µ = 0 is accepted since the test statistic
value did not exceed the critical value. We can con-
clude that the most suitable distribution for the ineffi-
ciency is the half-normal distribution. Finally, the null
hypothesis H
0
: η = 0 implies that the technical inef-
ficiencies are time invariant. This is rejected showing
that time does significantly influence the technical in-
efficiencies in the production model. From the results
of these hypothesis tests, we can conclude that the
most preferable form of the production function for
the data set is the translog stochastic frontier produc-
tion function with the inefficiency assumed to follow
a half-normal distribution and are time-variant.
4 CONCLUSION
This study set out to estimate the technical efficiency
(TE) of producing crude palm oil (CPO) in Malaysia
by applying the parametric stochastic frontier analy-
sis (SFA) technique. The overall mean TE is 0.79.
We found that fruit mill capacity, labour and time as
input variables significantly affect the level of CPO
output. Labour and time variables have positive rela-
tionship with the output level. On the other hand, fruit
mill capacity was shown to have a negative relation-
ship with the CPO production which could possibly
indicate that the mills are not utilized to their full ca-
pacity. Plantation area was proven to be statistically
insignificant in affecting output level. 71.6% of the
variation in deviations were due to technical ineffi-
ciencies whereas 28.4% were cause by the stochastic
random error. SFA estimated the state of Selangor to
be the most efficient CPO producing state among our
population and the state of Malacca to be the least
efficient. Even though the average efficiency of the
Malaysian CPO industry seems to be increasing grad-
ually each year, there is still room for improvement.
Inefficiencies could be reduced by managing existing
resources better, utilization of idle capacity, operat-
ing at optimal scale and applying the ways of efficient
states. The status of fruit mills in Malaysia needs to
be looked at as it was discovered to have a negative re-
lationship with output level. The existing mills possi-
bly are not fully utilized. Future study should be done
on the productivity of CPO production based on the
size of fruit mills and whether smaller fruit mills are
easier to manage and monitor. The productivity of the
whole industry decreases each year due to technologi-
cal change. Thus, investing in new technology is what
needs to be done to encourage productivity growth in
the industry. It is recommended that further study be
done on identifying the factors influencing the TE of
producing CPO in Malaysia preferably using the SFA
(Coelli, 1995) model specification. The inclusion of
environmental variables is highly suggested such as
rainfall and temperature.
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