We have analyzed the Bangladesh Household Income and Expenditure Survey (HIES) data from years 2000, 2005, 2010, and 2016 to estimates food and protein demand elasticities for fish, meat, poultry, and poultry eggs . We have used Quadratic Almost Ideal Demand System (QAIDS) models to estimate demand elasticities. For derivation of nutrient (protein) elasticities, we have matched consumption information in HIES with nutritional contents of the food consumed. The results of the QUAIDS model are divided into two levels: aggregate animal protein-source level and disaggregated fish level. At the aggregate level, we have investigated the demand for fish with other sources of protein that include meat, poultry, and poultry eggs. Meat consists of beef, buffalo, and mutton. Poultry and poultry eggs are comprised of hen and duck. For fish, we disaggregated into 12 different categories, covering both aquaculture and capture species. To calculate the expenditure elasticity, we have divided the HIES data into four quantiles , segregated based on the yearly expenditure of the households.
At the aggregate level, o n average, the own-price elasticities of sources of animal protein vary from -0.32 to -3.79, demonstrating the heterogeneity of demand for animal protein across the years. The own-price elasticities of fish can be considered almost unitary elastic, except for the year 2000. E xpenditure elasticities of all sources of animal protein are positive, indicating that fish, meat, poultry, and poultry egg are considered a normal good by households, regardless of their wealth status.
At the disaggregate level, the own-price elasticities of fish species produced through aquaculture, particularly tilapia , pangasius, and exotic carps are greater than one , and they follow a downward trend across the years. Their own-price protein elasticities are less than 1, and a small decline in demand with a change in price. Own-price elasticities of hilsa and Indian carps are greater than one ; however, they decline across the years. The own-price protein elasticities of Indian carps and hilsa are inelastic and these elasticities do not decline much across the years. Most of the cross-price elasticities and cross-price protein elasticities of fish across the species are positive implying that majority of the fish species are substitutes to each other. On the other hand, fish species like exotic carps , shol/gojar/taki, tilapia/puti, small fish species (mala/kachi/chapila ) are found to be complements with pangasius and airbreathing fish for years 2000 and 2005. Expenditure elasticities and expenditure protein elasticities of fish across the species over the four survey years are found to be positive, indicating that fish in general is considered as the normal good in Bangladesh. However, expenditure elasticities of hilsa are elastic with a value greater than one. This suggests that hilsa is a luxury fish in Bangladesh.