# 6.3. Parameters

Short explanation of parameters

 $$c_{i,0}$$ baseline costs of harvesting in the year $$t_0$$ (usually 2020) $$\tau_{i}$$ exponential time trend (positive or negative) on costs of harvesting $$\chi_{i}$$ stock elasticity. If >1 the stock is hypersensitive: fishing costs decline fast with accessible biomass. If <1 the stock is hyperstable and fishing costs remain relatively constant with the available biomass $$\beta_{i,s}$$ consumer preferences for different sizes (s) of each species (i). $$sum_s \beta_{i,s}=1$$ $$\alpha_{i}$$ consumer preferences for different species (i). $$sum_i \alpha_{i}=1$$ $$\eta$$ elasticity of demand for fish $$\gamma$$ weight of fish consumption in total utility. When $$\eta=1$$ it is the total expenditure on fish
 $$\mu_i$$ elasticity of substitution between different sizes of a species (i). Higher values indicate easier substitutability $$\sigma$$ elasticity of substitution between species of fish. Should be lower than $$\mu_i$$ since sizes are better substitutes than species.