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โครงการหนังสืออิเล็กทรอนิกส์ด้านการเกษตร เฉลิมพระเกียรติพระบาทสมเด็จพระเจ้าอยู่หัว

ECM). This examined the possibility that a natural disaster in a foreign country can affect the world crop

price and indirectly affect Thailand’s domestic crop prices through the price transmission process.
For Case 1 or the effects of natural disasters in Thailand on the quantity of each of the crops using

the Interruptible Time-series Analysis, the natural disaster data used in this part of the study are natural

disasters that happened in the provinces with the highest production quantity of each crop. Therefore, in
the cases of rubber and oil palm, the province with the highest production is Surat Thani and, thus, the

natural disasters that occur are mostly flood. When the flood does not last too long, the flood may damage

the palm fruits. However, for both rubber and oil palm tree, the damage on the trunks and roots can be

recovered. Nevertheless, a long period of rainfall and flood can impede the harvesting process. Empirically,
flood had no significant effect on the rubber production except for the great flood in 2010, which had a

significant negative effect on the production quantity. The results were different for Palm. Flood had a

significant positive effect on the palm production in the period when the flood started. However, the

quantity dropped afterward. This may be due to the more flexible harvesting period of oil palm. For cassava,
the province with the highest production is Nakorn Rajsima and the most common natural disaster is

draught. Effects of draught on the cassava production are diverse. In contrast to the case of rubber or oil

palm where the product can be harvest throughout the year, cassava requires 10-12 months to grow before
they can be harvested. Therefore, effects of draught on the production depend on the timing of the draught

in the production cycle of cassava. It should be noted that, this study did not perform this part of analysis

on paddy production as Jasmine is in-season rice and monthly data are complex to analyze.
For Case 2 or the short-run and long-run relationships between domestic crop prices in Thailand

and commodity futures prices in foreign countries using the MS-ECM, with the data limitation, this study

only examined the case of rubber prices. In particular, this study examined the relationships between the
farm gate price of unsmoked rubber sheet No.3 and the Ribbed Smoked Sheet (RSS) No.3 from the Tokyo

Commodity Exchange or TOCOM market. The results show price transmission from the TOCOM price to

Thailand’s farm gate price. This implies that external shocks such as natural disasters in other countries can
indirectly affect farmers’ prices in Thailand both in the short-run and long-run. The MS-ECM models

suggest that these short-run and long-run relationships differ across two states of the market. State 1 is the

time period from January 1986 to September 1997 and State 2 is from October 1997 to December 2016.

The results show no significant long-run relationship between the Thai and TOCOM prices in State 1.
However, the results show a significant long-run relationship in State 2 or after October 1997. For the short-

run, the results show significant relationships in both states.

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