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Chain Ladder Bias

Published online by Cambridge University Press:  17 April 2015

Greg Taylor*
Affiliation:
Taylor Fry Consulting Actuaries, Level 8, 30 Clarence Street, Sydney NSW 2000, Australia Centre for Actuarial Studies, Faculty of Economics and Commerce, University of Melbourne, Parkville VIC 3052, Australia, Phone: 61-2-9249-2901, Fax: 61-2-9249-2999, greg@taylorfry.com.au
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Abstract

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The chain ladder forecast of outstanding losses is known to be unbiased under suitable assumptions. According to these assumptions, claim payments in any cell of a payment triangle are dependent on those from preceding development years of the same accident year. If all cells are assumed stochastically independent, the forecast is no longer unbiased. Section 5 shows that, under rather general assumptions, it is biased upward. This result is linked to earlier work on some stochastic versions of the chain ladder.

Type
Articles
Copyright
Copyright © ASTIN Bulletin 2003

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