Sains Malaysiana 54(3)(2025): 913-926

http://doi.org/10.17576/jsm-2025-5403-22

Forecasting Life Expectancy using Latent and Observable Factors: Effects of Urbanization on Mortality Modelling

(Ramalan Jangka Hayat menggunakan Faktor Terpendam dan Boleh Diperhatikan: Kesan Urbanisasi terhadap Pemodelan Kematian)

NORKHAIRUNNISA REDZWAN^1,2 & ROZITA RAMLI^1,*

¹Department of Mathematical Sciences, Faculty of Science & Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

²School of Mathematical Sciences, College of Computing, Informatics and Mathematics, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia

Received: 21 May 2024/Accepted: 10 December 2024

Abstract

Sustainable development of the future is influenced by population growth, population ageing, migration, and urbanization. However, urbanization have adverse effects on environmental, social behaviour and health aspects, such as mortality risks due to climate change and infectious diseases. As the urban population is growing rapidly, there is a need to accurately forecasts these risks in anticipation of future ageing population, by developing a model to estimate and forecast mortality. Many existing extrapolative mortality models are described by latent factors, and it is difficult to understand the underlying dynamics of these factors. Therefore, a comprehensive analysis on the relationship between mortality index and urbanization growth were conducted. This study also aims to propose a new model that incorporates urbanization as an observable factor in modelling and forecasting mortality, by extending the Lee-Carter model. Result indicates that there is a possible long-run relationship between mortality and growth of urban population for all countries in the study. The proposed model provides better in-sample fitting for all countries. This study also predicts the life expectancy at birth based on the proposed model and life expectancy is forecast to reach age 85 for selected countries. Results also show that Malaysian adults ages between 20 and 40 years old are more likely to be affected by an increase in urbanization growth. Urbanization and mortality are key factors in planning for sustainable development of the future. Therefore, it is important to develop a mortality forecasting model that can account for the uncertainty surrounding urbanization.

Keywords: Forecasts; Lee-Carter; life expectancy; mortality; urbanization

Abstrak

Pembangunan mampan masa depan dipengaruhi oleh pertumbuhan penduduk, penuaan penduduk, penghijrahan dan urbanisasi. Walau bagaimanapun, urbanisasi mempunyai kesan buruk terhadap aspek alam sekitar, tingkah laku sosial dan kesihatan, seperti risiko kematian akibat perubahan iklim dan penyakit berjangkit. Oleh kerana penduduk bandar berkembang pesat, terdapat keperluan untuk meramalkan risiko ini dengan tepat dalam jangkaan penduduk menua masa depan, dengan membangunkan model untuk menganggar dan meramal kematian. Banyak model kematian ekstrapolatif sedia ada digambarkan oleh faktor pendam, yang sukar untuk difahami. Oleh itu, analisis komprehensif mengenai hubungan antara indeks kematian dan pertumbuhan urbanisasi dijalankan. Kajian ini juga bertujuan untuk mencadangkan model baharu yang menggabungkan urbanisasi sebagai faktor boleh cerap dengan faktor pendam dalam pemodelan dan ramalan kematian, sebagai model lanjutan Lee-Carter. Keputusan menunjukkan bahawa terdapat hubungan jangka panjang antara kematian dan pertumbuhan penduduk bandar untuk semua negara dalam kajian ini. Model yang dicadangkan memberi penyuaian sampel yang lebih baik untuk semua negara. Kajian ini turut meramalkan jangka hayat ketika lahir berdasarkan model cadangan dan jangka hayat dijangka mencapai umur 85 tahun bagi negara-negara terpilih. Keputusan kajian juga menunjukkan bahawaorang dewasa Malaysia yang berumur antara 20 dan 40 tahun lebih cenderung terjejas oleh peningkatan pertumbuhan urbanisasi. Urbanisasi dan kematian adalah faktor utama dalam merancang pembangunan mampan masa depan. Oleh itu, adalah penting untuk membangunkan model ramalan kematian yang boleh mengambil kira ketidakpastian dalam urbanisasi.

Kata kunci: Jangka hayat; kematian; Lee-Carter; ramalan; urbanisasi

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*Corresponding author; email: itaramli@ukm.edu.my