Do you ever wonder what proportion of email is spam?

Do you ever get frustrated having to delete spam?

A new IZA working paper by Caliendo, Clement, Papies and Scheel-Kopeinig reports that more than 70% of global e-mail traffic consists of unsolicited and commercial direct marketing (also known as "spam"). From an economic point of view, the authors point out that dealing with spam incurs high costs for organisations. The logical response? To reduce spam-related costs by installing spam filters.

Caliendo et al are interested in the selection bias associated with installing a spam filter. Using data from a German university, they measure the (time use) costs associated with spam, and the costs savings of spam filters. Their findings indicate that central IT costs are of little relevance since the majority of spam costs stem from employees who spend working time identifying and deleting spam. Also, the working time lost due to spam is approximately 1,200 minutes per employee per year. Caliendo et al suggest that these costs could be reduced by roughly 35% through the installation of a spam filter mechanism.

As another alternative, people could switch to email providers with inbuilt spam filters (automatic filtering perhaps...). I never get spam in my Gmail inbox; and emails that I want to receive there are never blocked.