A Quick Method for Assessing Economic Damage Caused by Natural Disasters: An Epidemiological Approach
Hayashi, Mampei, International Advances in Economic Research
Abstract In the aftermath of any natural disaster, a quick assessment of economic damage is called for, without which recovery planning and fiscal budgeting is impossible. What is customarily done as damage accounting is to use some aggregation by parts method, which is predisposed to commit double counting, omission, and bureaucratic inconsistencies. As an alternative, we propose to work with a social epidemiological model. First, we present a result by means of a log linear model which shows evidence of hazard factors and vulnerability factors at work. We then simplify the model by deleting the variables that are not significant in a linear formulation. Lastly, we give our estimate of economic damage for the case of the North East Japan Earthquake and Tsunami of March 11, 2011 and alert that the true damage may well be the double of government's estimate.
Keywords Direct economic damage * Natural disaster * Epidemiological model
JEL 3 * 15 * 29 * 31
Japan is a natural disaster prone country. Figure 1 compares the top 10 countries in terms of the occurrences of natural disaster per 100,000 square kilometers of land territory for the period 1990-2010. Japan ranks number two after the Philippines. Among the high income countries, however, Japan stands at the top by the same metric.
[FIGURE 1 OMITTED]
In any occurrence of a natural disaster, it is imperative, as well as academically challenging, to assess the value of economic damage involved. From a practical point of view, assessment needs to be done in the midst of an on-going emergency, where time is the most scarce resource of all. In retrospect, it must be conducted in order to search for possible policy measures for future mitigation.
However, as Cochrane (2004, pp.290-291) says in relation to the 9/11 incident in New York, 2001, "Loss accounting, as currently practiced, is problematic for several reasons." He goes on to say that" ... most problems stem from double counting, failure to identify clearly an accounting stance, ignoring non-market losses, confusion as to whether post-disaster economic trends are a product of the event or some other unrelated factor, and the employment of too limited a time frame."
Thus, the purpose of this paper is to present a simple epidemiological model for assessing economic damage, which is applicable to any event or natural disaster. The method comprises an alternative to the common accounting practice of aggregation by parts.
In the next section, we will explain what is commonly done in Japan regarding the economic damage measurement. In the section following that, we will present a social epidemiological model of hazard and vulnerability leading to economic damage. We will then examine the data availability and select variables to be used for estimation. Finally, we will present the fixed effect estimation result.
In the section after that, we will propose yet another model of a simple equation, which is convenient for a quick estimation. By applying this method to calculate the damage of the North East Japan earthquakes and tsunami of March 11, 2011 (the Tohoku earthquake), we conclude that the true direct economic damage may well be the double of government's estimation.
Measurement of Post-Disaster Economic Damage: The Common Practice
The Fire and Disaster Management Agency (FDMA) of the Japanese government has been compiling statistics regarding natural disasters based on reports filed by 47 prefectures. (1) The FDMA classification of disaster damage is shown in Table 1. All types of damage are reported in physical units except economic damage.
Table 1 FDMA classification of Natural disasters damage Damage Type of damage Unit classification Human damage dead person missing person injured seriously person injured injured person affected population affected household household affected person population Building damage housing damage totally building destroyed half building destroyed partially building destroyed inundated building above floor inundated building below floor- non-housing public building buildings other building Others rice field destroyed ha rice field flooded ha fruit and vegetable ha patch destroyed fruit and vegetable ha patch flooded Public public school campus infrastructure infrastructure bridge bridge river site landslide site Transportation railway blocked site ship ship Economic damage thousand yen
Data is compiled on a yearly basis, and it covers the period 1995-2007. …