Natural disasters, the economy and population vulnerability as a vicious cycle with exogenous hazards

One way to understand the growing impact of disasters is as the output of a positive feedback, or reinforcing, loop. This paper hypothesizes that population vulnerability of a country transforms exogenous hazards to disaster impact for that country, which negatively impacts its economy as measured by per capita income and its growth. This impact in turn increases the vulnerability of the country's population thus creating a reinforcing loop. Therefore, like the output of any positive feedback loop, disaster impact would grow exponentially. Having analysed data over 50 years (1963–2012) and 179 countries, we find the results to be consistent with this conceptual model. We also find that disaster impact worldwide has indeed grown exponentially over this period even after normalizing for the growing global population and global income. These findings indicate the existence of a feedback loop that requires strategic rethinking about disaster management and development jointly to break this vicious cycle.