Abstract
E-mail is an efficient communication tool, but at the same time it is an efficient vehicle for Internet pollution in the form of spam—unsolicited, bulk e-mailings. Spam is a global phenomenon, and debate about possible means of controlling it is lively. Spammers impose a negative externality on users. The volume of spam-type e-mail sent is above the social optimum and thus produces dead-weight. To solve the spam problem and evaluate spam-control measures, one needs to measure the disutility experienced by e-mail users who receive spam. The current study employs conjoint analysis of stated-preference data to estimate e-mail users’ overall inconvenience cost attributable to spam. The results show the inconvenience cost of spam to be about 3.067 won (US$ 0.0026) per spam message.
Notes
1 Attention bond mechanism is an economic solution to spam that allocates e-mail receivers’ attention. Each receiver set the size of attention bond that can be adjusted to receivers’ opportunity costs and e-mail is delivered after receivers’ permission.
2 According to Ferris Research (Citation2003) spam cost US corporations more than $10 billion in 2003. The Korean Information Security Agency (Citation2003) and Nara Research (Citation2004) reported that in Korea spam cost $11 billion and $43 billion in 2003 and 2004 respectively.
3 Yoo et al . (Citation2005) estimated consumers’ willingness to pay for a spam-blocking program using a contingent valuation method.
4 Part-worth is calculated as estimate times variation between the maximum and minimum levels of an attribute.
5 In the case of obscene spam, willingness to pay for a decrease of one message can be calculated as follows:
6 According to the International Telecommunications Union (2004), some 36% of spam consists of an attempt to deceptively sell something or perpetrate a scam or fraud.