Impact estimation of disasters : a global aggregate for 1960 to 2007

This paper aims to estimate the global aggregate of disaster impacts during 1960 to 2007 using Social Accounting Matrix (SAM) methodology. The authors selected 184 major disasters in terms of the size of economic damages, based on the data available from the International Emergency Disasters and MunichRe (NatCat) databases for natural catastrophes. They estimate the losses and total impacts including the higher-order effects of these disasters using social accounting matrices constructed for this study. Although the aggregate damages based on the data amount to US$742 billion, the aggregate losses and total impacts are estimated at US$360 billion and US$678 billion, respectively. The results show a growing trend of economic impacts over time in absolute value. However, once the data and estimates are normalized using global gross domestic product, the historical trend of total impacts becomes statistically insignificant. The visual observation confirms the inverted ‘U’ curve distribution between total impact and income level, while statistical analyses indicate negative linear relationships between them for climatological, geophysical, and especially hydrological events.