A Multistage Budgeting Approach to the Analysis of Demand for Fish: An Application to Inland Areas of Bangladesh

This study was conducted to estimate the elasticities of demand for eight different fish types and four income groups in Bangladesh using year-round data collected from inland areas of the country. It uses a three-stage budgeting framework that estimates a demand function for food in the first stage, a demand function for fish (as a group) in the second stage, and a set of demand functions for fish by type in the third stage using a quadratic extension of the Almost Ideal Demand System (QUAIDS) model. The Heckman procedure was used in stage three to remove the possible bias in the parameter estimates brought about by zero consumption. The magnitude of both price and income elasticities varies across different fish types and income quartile groups, indicating the relevance of estimation specific to fish types and quartiles. Except for assorted small fish, the other seven fish types included in the study were found to have positive income elasticity for all income levels. Assorted small fish is an inferior commodity for the richest quartile of the population.