Research from the University of Warwick suggests suicide rates are much higher in protestant areas than catholic areas.
Professor Sascha Becker from the University of Warwick's Centre for Competitive Advantage in the Global Society (CAGE) has published his latest paper Knocking on Heaven's Door? Protestantism and Suicide.
The study investigates whether religion is an influence in the decision to commit suicide, above and beyond other matters that may play a role, such as the weather, literacy, mental health or financial situation.
Professor Becker and his co-author, Ludger Woessmann from the University of Munich, used data from Prussia in the 19th Century and 21st Century data from the Organisation for Economic Co-operation and Development (OECD).
Professor Becker said: "We used the 19th Century data because at this time virtually everyone adhered to a religious denomination and religion pervaded virtually all aspects of life. In Prussia both Protestants and Catholics were non-minorities living together in one state and the two religions give a basis for comparison.
"The results were quite striking, in the 19th Century suicide rates among Protestants in Prussia were roughly three times as high as among Catholics."
The researchers then compared their findings to the OECD data and found there was still a difference.
Professor Becker said: "Even today, countries that are majority Protestant tend to have substantially higher suicide rates than those which are majority Catholic, suggesting that the relation of religion and suicide remains a vital topic."
Professor Becker believes the structures of the two religions explain the differences in the data. Protestantism is a more individualistic religion, whereas Catholicism has a stronger community structure.
He said: "When life hits hard, a Catholic can rely on a stronger community which might help him to cope. Secondly, Protestantism stresses the importance of God's grace alone and not by any merit of man's own work, whereas Catholicism allows for God's judgement to be affected by man's deeds and sins. As a consequence, committing suicide entails the prospect of foregoing paradise for Catholics but not for Protestants."
Another factor for Catholics is the confession of sins. Since suicide is the only sin that (by definition) can no longer be confessed, this creates an additional reason to deter Catholics from committing suicide.
Professor Becker added: "Suicide is affected by all these factors the structure of the religious community, strongly held views about God's grace, and the impossibility of confessing the sin of suicide. As a result, we conclude that religion matters in life and death."
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Knocking on Heaven's Door? Protestantism and Suicide is available in the Warwick Economics Research Paper Series