London, Nov 20 (IANS): A significant study has revealed that on average, terrorism decreases fertility - reducing both the expected number of children a woman has over her lifetime and the number of live births occurring during each year.

"Besides illuminating another far-reaching effect of terrorism, the relationship between terrorism and fertility will be critical to understand when policymakers attempt to deal with other demographic transitions and security concerns," said Claude Berrebi from Hebrew University, Jerusalem.

For the study, the researchers used a panel data set composed of data on terrorist attacks from 1970-2007 as well as a variety of demographic controls, to implement a robust panel analysis and measure the effects of terrorism on fertility as expressed by Total Fertility Rates (TFR) and Crude Birth Rate (CBR).

The data consisted of 170 countries and 5,842 individual country-year observations and after filtering, the set of individual incidents studied was approximately 66,000.

After rigorous analysis, it was found that terrorism is likely to act on fertility through job uncertainty, psychological stress, wealth uncertainty and poor health.

"This can cause significant short-term declines in fertility by affecting related factors such as age at first birth, age at marriage, frequency of sexual intercourse and labour migration," said Jordan Ostwald of the US Air Force.

Measured by both the number of incidents and the number of deaths, terrorism was shown to exert a statistically significant, negative effect on fertility rates for both TFR and CBR.

"Rather than demographic change being the root cause of terrorism, using sophisticated empirical analysis, we were able to identify causal effects of terrorism on larger-scale demographic transitions. Our findings explain some of the disparities between previous theories and results and put to rest some notions suggesting reverse directionality."

The study appeared in the journal Oxford Economic Papers.