Spam mails impede economic growth

We estimate labor losses caused by spam mails and input these estimated values into a production function, while also estimating damage to the Gross Domestic Product (GDP) in Japan. As a result, we have found that spam mails decreased the Japanese GDP by about 500 billion yen in 2004. This marginal negative effect of spam mail to the GDP increased with the progress of broadband in 2000. Moreover, from the result of a social simulation conducted by the authors, the amount of damage is projected to reach 1% of the Japanese GDP by 2010, unless adequate countermeasures are taken against spam mails. This projection provides a statistical fundamental to several theoretical analyses of spam mails.