Description: This is a letter from Jan M. Hoem to Arnold F. Shapiro about Exposed-to-risk considerations based on the Balducci assumption and other assumptions in the analysis of mortality.

Description: The Lee and Carter LC method is getting widely adopted for long-run forecasts of age specific mortality rates. That popularity is first due to the model simplicity. Moreover, the LC model has given successful results for various countries e.g. U.S., Chile, G7 countries. However, some difficulties arose when using population data from certain countries such as UK and Australia. In the present paper, the LC model is applied to data from four Nordic countries: Denmark, Finland, Norway and Sweden. The Singular Value Decomposition SVD, the Weighted Least Square WLS and the Maximum Likelihood estimate MLE are used. These approaches give satisfactory results. The appropriate fitting period needs, however, to be well chosen. The properties of the model's parameters are studied using a bootstrap simulation.