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Sains Malaysiana 54(6)(2025): 1617-1628

http://doi.org/10.17576/jsm-2025-5406-16

 

Detection Procedure of Structural Changes in State-Space Models: Impulse and Steps Indicator Saturation Technique

(Prosedur Pengesanan Perubahan Struktur dalam Model Ruang-Keadaan: Teknik Ketepuan Penunjuk Impuls dan Langkah)

 

FARID ZAMANI CHE ROSE1,*, MOHD TAHIR ISMAIL2, MUHAMMAD ASLAM SAFARI1, NUR AQILAH KHADIJAH ROSILI3 & MUHAMMAD FADHIL MARSANI2

 

1Department of Mathematics and Statistics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

2School of Mathematical Sciences, Universiti Sains Malaysia, USM Minden, 11800 Pulau Pinang, Malaysia

3Faculty of Computing and Engineering, Quest International University, 30250 Ipoh, Perak, Malaysia

 

Received: 18 July 2024/Accepted: 13 March 2025

 

Abstract

The presence of extreme structural change in a sequence of data points over time may have a detrimental impact on the estimation of economic and financial indicators. Anomalies caused by these extreme values can distort the estimated parameters, diminish the accuracy of the time series model, and potentially lead to inaccurate forecasts. In this research, a general-to-specific modeling approach is utilized to identify the structural changes through indicator saturation within the framework of a state-space models as an alternative to current method. By focusing on impulse and steps indicator saturation, this study evaluates their effectiveness through Monte Carlo simulations that are replicated 1000 times. The Monte Carlo experiments demonstrate that the efficiency of indicator saturation is heavily dependent on factors such as the magnitude of the structural change, the level of statistical significance, and the position of an extreme value within the series. Subsequently, this study employs the combined impulse and steps indicator saturation to detect structural breaks in the FTSE 100 daily closed stock price index. The most important findings relate to the coefficients for the structural breaks at  and  are estimated at  and , respectively. The findings show that the characteristics, position, and direction of the extreme values detected by impulse indicator saturation coincide with the occurrence of the COVID-19 pandemic, which has had a global impact on economic activities. This finding may lead to better understanding of how the stock markets in UK reacts to government policy due to the COVID-19 pandemic.

Keywords: General-to-specific; indicator saturation; model selection; Monte Carlo; structural changes

 

Abstrak

Kehadiran perubahan struktur yang ketara dalam satu data siri masa boleh memberi kesan buruk terhadap penganggaran penunjuk ekonomi dan kewangan. Nilai melampau yang menyebabkan anomali boleh memesongkan parameter yang dianggarkan, mengurangkan ketepatan model siri masa dan berpotensi menghasilkan ramalan yang tidak tepat. Dalam kajian ini, pendekatan pemodelan umum kepada khusus digunakan untuk mengenal pasti perubahan struktur melalui petunjuk ketepuan dalam kerangka model ruang keadaan sebagai alternatif kepada kaedah semasa. Dengan memberi tumpuan kepada petunjuk ketepuan impuls dan langkah, kajian ini menilai keberkesanannya melalui simulasi Monte Carlo yang diulang sebanyak 1000 kali. Uji kaji Monte Carlo menunjukkan bahawa kecekapan ketepuan penunjuk sangat bergantung kepada faktor seperti magnitud perubahan struktur, tahap signifikan statistik dan kedudukan nilai ekstrem dalam siri data tersebut. Seterusnya, kajian ini menggunakan gabungan ketepuan penunjuk impuls dan langkah untuk mengesan perubahan struktur dalam indeks harga penutup harian FTSE 100. Penemuan paling penting berkaitan dengan pekali bagi perubahan struktur pada penemuan ini menunjukkan bahawa ciri, kedudukan dan arah nilai melampau yang dikesan oleh ketepuan penunjuk impuls bertepatan dengan berlakunya pandemik COVID-19, yang telah memberi kesan global terhadap aktiviti ekonomi. Penemuan ini boleh membawa kepada pemahaman yang lebih baik tentang bagaimana pasaran saham di UK bertindak balas terhadap dasar kerajaan akibat pandemik COVID-19.

Kata kunci: Monte Carlo; pemilihan model; perubahan struktur; petunjuk ketepuan; umum kepada tertentu

 

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*Corresponding author; email: faridzamani@upm.edu.my

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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