I am interested in modeling aggregate CPI as the weighted sum of its components. To do so, I need to incorporate the weights, but I am unsure about the best way to implement them in Dynare. One option is to treat them as constant parameters, but then I will ignore the changes that occur every few years. Another option is to make them endogenous variables driven by corresponding shocks, and then use the historical weights as observables. This might work, but it also has several drawbacks. The likelihood will be distorted, the computational cost will be higher, and there might be other issues.
Does anyone have a better suggestion?