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