# Pairwise estimation

### Description

Estimating population size based on any pair of samples

### Usage

1 | ```
estN.pair(z)
``` |

### Arguments

`z` |
the vector of capture histories or ascertainment records. |

### Value

estimates based on any pair of samples

### Note

Refer to Seber (1982, pages 59 and 60) for the Petersen estimator and the Chapman estimator as well as s.e. formula.

A log-transformation is used to obtain the confidence interval so that the lower limit is always greater than the number of ascertained. Refer to Chao (1987, Biometrics,43, 783-791) for the construction of the confidence interval.

### References

Chao, A. (1987). Estimating the population size for capture-recapture data with unequal catchability. Biometrics, 43: 783-791.

Chao, A., Tsay, P. K., Lin, S. H., Shau, W. Y., and Chao, D. Y. (2001). The applications of capture-recapture models to epidemiological data. Statistics in Medicine, 20: 3123-3157.

Seber, G. A. F. (1982). The estimation of animal abundance (2 ed.): Griffin, London.

### Examples

1 2 |