search for: farmprice

Hi I was trying to estimate simultaneous equation system in R using systemfit. I used the following commands >library(systemfit) > data(Kmenta) > attach(Kmenta) >eqDemand<-consump~price+income > eqSupply<-consump~price+farmprice+trend > fitsur<-systemfit("SUR",list(demand=eqDemand, supply=eqSupply)) and got the following error messege Error in systemfit("SUR", list(demand = eqDemand, supply = eqSupply)) : argument 'formula' must be an object of class 'formula' or a list of objects...

Hi there, I am really new to statistics in R and statistics itself as well. My situation: I ran a lot of OLS regressions with different independent variables. (using the lm() function). After having done that, I know there is endogeneity due to omitted variables. (or perhaps due to any other reasons). And here comes the Hausman test. I know this test is used to identify endogeneity. But what I

...de to make one call to systemfit because I really should be using SUR rather than a sequence of lms. But, systemfit needs the following type of setup. #xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx eqDemand <- consump ~ -1 + price + income eqSupply <- consump ~ -1 + price + farmPrice + trend system<-list( demand = eqDemand, supply = eqSupply) #xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Then, the call to systemfit is fitsur<- systemfit( "SUR", system) Does anyone know how to change the code in the for loop ( I can deal with the two lines...