# On the estimation of population size from a post-stratified two sample capture-recapture data under dependence

## TL;DR

This paper introduces a new model for population size estimation using two sample capture-recapture data that accounts for dependency between capture and recapture, improving accuracy over traditional methods.

## Contribution

The paper proposes a novel model that incorporates dependency in capture-recapture data and develops estimation methods for this model, addressing a gap in existing literature.

## Key findings

- Proposed model outperforms existing methods in simulations.
- Method effectively captures dependency between capture and recapture.
- Illustrated with real data analysis.

## Abstract

Population size estimation based on two sample capture-recapture type experiment is an interesting problem in various fields including epidemiology, pubic health, population studies, etc. The Lincoln-Petersen estimate is popularly used under the assumption that capture and recapture status of each individual is independent. However, in many real life scenarios, there is an inherent dependency between capture and recapture attempts which is not well-studied in the literature of the dual system or two sample capture-recapture method. In this article, we propose a novel model that successfully incorporates the possible causal dependency and provide corresponding estimation methodologies for the associated model parameters based on post-stratified two sample capture-recapture data. The superiority of the performance of the proposed model over the existing competitors is established through an extensive simulation study. The method is illustrated through analysis of some real data sets.