ACCURATION OF INDONESIAN RICE SUPPLY AND DEMAND FORECASTING FOR FOOD AVAILABILITY

Abstract

Accuration of forecasting is very usefull as a base for policy making in the future. This
study aimed to test accuration of Indonesian rice supply and demand forecasting in 2015
which was made in 2006. Study was done on national scale used secondary data between
1970-2004 which was obtain from legitimate institution publication. Forecasting was done
through these steps : (a) model equation arranging, (b) model identifying, (c) model
estimating and parameter testing by two stage least square methode using SAS program
analysis software, (d) model validation test, and (e) exogenous variable forecasting using
exponential smoothing methode. Forecasting result was compared with official data in 2015
published by Center for Agriculture Data and Information System, Ministry of Agriculture
Republik of Indonesia (2016). Accuration was based on % deviation between official source
and forecasting result, the more deviation the more non accurate. The results were: (a) There
was a big deviation (109.16%) between official source and forecasting calculation on
Indonesian food avaiability in 2015. Based on official source, Indonesian rice supply was
44,710,528 tonnes, demand was 32,388,271 tonnes and availability was surplus 12,322,257
tonnes. The main cause of surplus was over estimate of harvested area. On the contrary
according to forecasting, supply was 40,894,521 tonnes, demand 42,023,699 tonnes, and
Indonesian food availability was deficit 1,129,178 tonnes. The main cause of deficit was using
of previous estimate of consumption/capita/year which was larger than official source so
demand became larger too. None of these calculation was matching with actual condition;
(b) Simulation using forecasting data which was calculated by official source way found out
that food availability which more close to real condition, that domestic production plus
861,630 tonnes amount of imported rice could fulfil demand and without calculating
national stock Indonesian food availability still surplus 1,164,574 tonnes in 2015.