Statistical Analysis of Coins Lost in Circulation
估计了1960-1979年以色列镑系列硬币的丢失率，建立带时变风险率的寿命模型，预测不同面额硬币的流通存活数量和寿命中位数，对货币管理有参考价值。
The loss rate of coins in the Israeli pound (IL) series issued in Israel in 1960–1979 is estimated, and the connection between it and the characteristics of the coins is examined. A lifetime model with time-dependent hazard rate and an estimation procedure for the model parameters are presented. The estimates are then used to forecast the number of coins surviving in circulation and the median lifetime of different denominations. The data are random samples drawn from the coins in circulation at a point in time, the sampled coins being sorted by date of issue.