Abstract production has increased because of the


Rice is one of the most important sources of
calorie and energy in human body. It plays an essential role in agrarian
economy sectors of Bangladesh .This study is an attempt to
measure the growth and instability in area, production and yield of rice in
Bangladesh based on secondary data during the period 1972 to 2016 collected
from Bangladesh Bureau of Statistics.
Different statistical tools have been used to perform the analysis. The analysis
reveals that the area, production and yield of rice have increased
significantly. Though the production of rice has increased but it is not
sufficient to meet the demand of the country. The analysis also reveals that
the area, production and yield of rice are not stable during the study period.
Therefore, researchers, policy makers and academicians should give proper
attention to develop new idea to increase the production of rice that fulfills
the demand of the country.

Instability, Production, Area, Rice and Growth Rate


population of Bangladesh is increasing rapidly. Rapid population growth, along
with unplanned urbanization, causes the cultivable land area to be used for
non-agricultural purpose. As a result, the cultivable area is reduced
significantly (Akther et al., 2016). Rice is the main food
for most of the people in Asia, almost half of world’s population live on rice
(Bhuiyan, 1992). Al most 2.4 billion people depends on rice and provides more
than 20% of their daily calorie intake (Lampe, 1995). The annual growth rate for rice
consumption in the Asia-Pacific Region over a period of 45 years (1950 to 1995)
has kept pace with the demand, more through yield increase rather than area
expansion (Papademetriou, 2000). Within 2030 our world population will
increased 8.27 billion and  we can ensure
enough rice for the increasing population (Kubo and Purevdorj, 2004).With an
increasing population leading to an increase in demand, the main drivers which
determine rice production need to be identified (Milovanovic and Smutka, 2017).
Rice production has increased because of the use of modern technology and the
price of rice is increasing due to rising agriculture wage rates and decline
availability of cultivable land (Ahmed, 2004). In
recent years the production of rice has increased in South Asian Countries but
in other countries of the region yields have stagnated (Mutert and Fairhurst, 2002). Bangladesh has huge population as
compared to many others country and it occupies 8th position over
the world because of over population. With the increase of population our
cultivated land in decreasing day by day. About 75% country’s
population is engaged in agricultural sector (BSGDMA, 2007). Rice is one
of the dominant crops of the agrarian economy of Bangladesh and it reflected in
the high per capita rice consumption in this country (Shelley et al, 2016). In Bangladesh rice production most rain fed rice is
faced problem because of drought and Diurnal temperature
range (Rahman et
al., 2017). Average yields per hectare and total
rice production increased significantly, leading to a substantial increase in
the supply of rice in the domestic market which resulted in significant
reductions in rice prices and the average production cost of rice per acre in
terms of input use varied across the three rice crops as well as across the
various stages of rice cultivation (Talukder and Chile,
2014). Despite pressure
from overpopulation, the country has reached self-sufficiency in rice
production (Shelley et al., 2016). Production of rice has increased because of
the development of high-yielding varieties and use of high level of fertilizer
in last four decades (Prasad
et al., 2016).

achieve better economy and fulfill the demand of increased population, it is
needed to increase the production of rice. Rice production and area should be
increased and yield rate should be stable. A good number of researches are done
in this sector. However, these research works are not sufficient to improve the
sector. Therefore, this study is investigated to know the change and
instability of rice production in Bangladesh.

and Methods:

Secondary sample data on area,
production and yield of rice for the last 45 years from 1972 to 2016 have been
collected from different issues of Statistical Yearbook of Bangladesh Bureau of
Statistics (BBS). The whole period was divided into two periods to compare in
area, production and yield of rice. Period I starts from 1972 to 1993 and
Period II from 1993 to 2016. To examine the nature of change, instability and
degree of relationship in area, production and yields of rice in Bangladesh,
various descriptive statistical tools, such as mean, correlation co-efficient
and coefficient of variation have been used. The t-test, simple linear
regression technique and semi log growth model have been used to analyze the
data. The data analyses have been performed by using SPSS software.


To estimate the parameters, simple
linear regression models has been fitted to examine the change of production by
the change of area. The model can be expressed as:


where, e ~N(0,), y is the production (in ton), x
is the area (in acre),  is the intercept and  is the regression coefficient of the model.

of Growth Rate

The growth rates of area, production and
yield of rice were workout by fitting a semi-log function of the type: ,where, y is the area (in acre) or production (in ton) or
yield (ton/acre) and t is the time period (in year).

of Instability

An index of instability in area
instability was computed for examining the nature and degree of instability in
area, production and yield of total rice in Bangladesh. The co-efficient of
Variation (CV) of rice was worked out for area, production and yield to measure
of variability. However, simple CV does not explain properly the trend
component inherent in the time series data. Alternatively, the coefficient  of variation around the mean (C) rather than co-efficient of
variation around the mean(CV) was suggested by Cuddy and Della(1978) as a
better measure of variability.

linear trend  was fitted to the
indices of area, production and yield for the study period and trend
co-efficient ‘ was tested for significance. Whenever the
trend co-efficient was found significant, the index of instability was
constructed as follows:

where ,
where  and s are the mean and standard deviation of
the sample period.

the index of instability ( is the multiplication coefficient of
variation to the square root of unexplained variation by the trend equation y=.

Result and Discussion

Change in Area, Production and Yield of Rice

As the number of people increased agricultural area of rice has
been increased. As a result the production of rice has been increased. The
cultivable area, production and yield of rice have increased 1.06, 1.78 and
1.89 times respectively during the last 45 years. The average production of
rice is 26561.10 metric tons in period II, while it was 14034 metric tons in
period I. The change between these two periods is highly significant (P< 0.01). Though, the production has increased significantly but it cannot meet the current demand of the country. From the analysis it is evident that there is a significant changed in area, production and yield of rice in Bangladesh (Table 1). Table 1: Change in area, production and yield of rice in Bangladesh   Mean Value t-value p-value Field of measurement Period-I Period-II     Area 25170.84 26598.23 -4.261 0.00 Production 14034.45 26561.10 -8.786 0.00 Yield 0.55560 0.9902 -9.84 0.00   Correlation Analysis From the correlation analysis it is observed that the production of rice is strongly positively correlated (r =.884) with its area for whole period. The relationship between production and area of rice is also highly significant which implies that the increment of area strongly affects the production of rice to increase. Similarly the area and production of rice for the period I and period II are also significantly correlated (Table 2). Table 2.Relationship between area and production of Rice in Bangladesh Criteria              Value of Correlation co-efficient (r) p-value   Area V Production   Whole-Period  0.884 0.01 Period-I  0.673 0.01 Period-II  0.953 0.01   Regression Analysis The simple linear regression models were fitted for estimating the response of production of rice due to the change of their respective area. The Results show that the estimated coefficients of production on area are significant during the whole period, Period I, and Period II. It implies that the production of rice has increased by 5.28, 2.15 and 4.33 times during the whole period, Period I and Period II due one unit increase in area respectively. So an increasing trend is found in rice production with the increase in its area (Table 3). Table 3.Testing dependency of production on area of Rice   Measurement Period Constant value Regression coefficient t-value p-value whole period -116244.49 5.28 12.43 0.00 Period I -40068.837 2.15 4.07 0.01 Period II -88671.335 4.33 14.37 0.00   Growth rate of area, production and yield of Rice Growth rate provides acceptable good measures of variation in past and it future change. The exponential model is used to measure growth rate. Since the cultivable area of rice is increased, the production is also increased. It is found that the growth rate of area, production and yield of rice are positive and significant during the whole period, period I and period II respectively. It is observed that the production of rice is increased 2.7%, 3.5% and 2.6% during the period I, period II and Whole period respectively. The growth rate of production is higher in period II than any other period. Similarly growth rate of yield is higher in period II than the whole period. So, a remarkable growth rate of area, production and yield of rice have been observed during the study period (Table 4).  Table 4: Growth rate of area, production and yield of Rice Field of Measurement Measurement  period Growth Rate (%) p-value   Whole period 0.3 0.00 Area Period I 0.3 0.001   Period II 0.7 0.00   Whole period 2.9 0.00 Production Period I 2.7 0.00   Period II 3.5 0.00   Whole period 2.6 0.00 Yield Period I 2.4 0.00   Period II 2.8 0.00   Instability in area, production and yield of Rice Fluctuation in area and production are correlated as larger area gives higher production if all other inputs remain constant. But instability of yield may be due to weather condition, natural calamities like floods, droughts, cyclone etc. and technical changes. So variation of agricultural production always exists in Bangladesh. Our analysis supports this claim. The production and yield of rice showed highest degree of instability during whole period. The area of rice also showed remarkable variation during the whole period. The area, production and yield of rice showed the significant fluctuation during study period (Table 5). Table 5: Instability in area, production and yield of rice in Bangladesh Field of Measurements Measurement  Statistics Whole period Period I Period II     Area     CV 5.1% 3.2% 5.1% R-Square 0.649 0.436 0.814 p-value 0.00 0.00 0.00 D-W 0.57 1.031 0.993 CV around trend line 3% 2.4% 2.2%     Production     CV 38.7% 18.1% 23.4% R-Square 0.936 0.953 0.968 p-value 0.00 0.00 0.00 D-W 0.218 1.95 0.898 CV around trend line 9.8% 3.9% 4.1%     Yield     CV 33.9% 16.4% 18.9% R-Square 0.96 0.937 0.975 p-value 0.00 0.00 0.00 D-W 0.25 1.156 0.886 CV around trend line 6.8% 4.1% 2.9%   Conclusion: Rice is the most important food in Bangladesh. The findings reveal that overall production of rice in Bangladesh is satisfactory as the average area, production and yield have increased. It is observed that the production and yield has increased for period I and period II.  The growth rate of area and production are also increased. Therefore, it is concluded that cultivable area is important factor to increase the production of rice. If we fail to increase cultivate land, the production will suffer most. But area is limited. So, it is better to consider other factors which affect the production. The production may be depends on quality of seeds, new technology, quality of fertilizer etc. So this research may be helpful for the stakeholders and policy makers to overcome food problems in Bangladesh. Acknowledgement We like to thanks the Bangladesh Bureau of Statistics to provide us their collected data.