Our present world is crammed with terrorism. It doesn’t only affects peace but it also brings severe damages to the economy. There has been much written about the short-term macroeconomic impact of terrorism attacks on investors risk aversion, equity market valuations, bond yields, oil prices, aggregate consumption and investment activity and even the medium-term effects in the regulatory, trade and fiscal policy responses by governments and the private sector, but much less is known about how this potentially long-lasting heightened terrorist threat affects the stock prices of individual firms.

Some studies have argued it may reveal itself in the psychological fear of terrorism that can affect economic behavior. Let us recall the 9/11 bombing. After that terrorist attack, insurers reduced or even rendered inexistent the supply of terrorism insurance throughout the economy, delaying or preventing many projects from going forward mostly construction in large cities because of creditor or investor concerns. The unprecedented terrorist attacks on that dreaded September 11, 2001 caused massive casualties and damage and ushered in an era of great uncertainty. That shocking display of brute force also changed the way we think about terrorism and moved the topic to the front-burner of academic and public attention. One important way in which we have changed our perspective about terrorism is as a geopolitical risk that affects the global economy and financial markets.

G. Andrew Karolyi and Rodolfo Martell, examined the stock price impact of terrorist attacks. Using an official list of terrorism-related incidents compiled by the Counter-terrorism Office of the U.S. Department of State, they identified 75 attacks between 1995 and 2002 in which publicly traded firms are targets. Looking at the event study analysis around the day of the attacks uncovers evidence of a statistically significant negative stock price reaction of -0.83%, which corresponds to an average loss per firm per attack of $401 million in firm market capitalization. A cross sectional analysis of the abnormal returns suggests that the impact of terrorist attacks differs according to the home country of the target firm and the country in which the incident occurred. Terrorist attacks in countries that are wealthier and more democratic are associated with larger negative share price reactions. Most intriguingly, we see that human capital losses, such as kidnappings of company executives, are associated with larger negative stock price reactions than physical losses, such as bombings of facilities or buildings.

The passage of U.S. Terrorism Risk Insurance Act (TRIA) in 2002, with its backstop provision of up to $100 billion zero-cost reinsurance for terrorism events, was indeed an important U.S. legislative event. But sadly, it did not provide for any long-term scheme for terrorism insurance and, even today, it is not clear which course of action the industry and government is to follow once TRIA expires in December 2005. Some argue that America cannot risk a gamble on terror insurance and that renewal of TRIA is critical as a private insurance market will never develop. Some experts goes on to saying that, catastrophic terrorism risk is uninsurable by the private market because its true dimensions are incalculable, whether you live in London, Madrid or New York.

With these dramatic view realizations of the market for terrorism insurance, we can argue that it is even more important now to develop new measures of the economic consequences of terrorism events to guide policy. In this article, the stock price reaction of publicly-traded firms that have been affected or targeted by a terrorist attack providing average estimates of the losses caused by these events has been used. Karolyi and Martells’ subsequent analysis of the cross-sectional variation in the stock price reactions suggests that losses inflicted by terrorist attacks are larger when they take the form of kidnappings. They also showed that these losses are greater when the firm is located in a richer country or in a country with a more democratic regime. It is important, though, to remember that their results were obtained using only a subset of the universe of terrorist incidents classified as such by the State Department, since they are studying only the reaction associated with publicly-traded companies. Also, in their study, they opted for a simplified approach and they only studied the short-term reaction of firms to these attacks and ignored potential longer-term effects on cash-flows or cost of capital (risk premium) effects. The re-emergence of a market for terrorism risk insurance demands that insurers generate better models to assess the likelihood and potential losses derived from terrorism. Their results suggest that characteristics of the attack (kidnappings vs. property destruction) and characteristics of the country of the targeted firms provide help in assessing the losses. They hope the results presented in their study may serve at least as a useful starting point in the current debate surrounding terrorism insurance, the renewal of TRIA and the characteristics of the legislation that will replace it.

In conclusion, to put it in a nutshell, an understanding of the nature of terrorism and the magnitudes of its effects is a prerequisite for designing successful policies to prevent terror, to alleviate the costs of terrorism, or to reduce an economys vulnerability to attacks.