Marc Jekel
2014-Jul-02 16:19 UTC
[R] robust standard errors in maximum likelihood estimation; sandwich estimator for mle/mle2
Dear list, After more reading, I can specify my rather broad question I asked yesterday and therefore ask a better question: I have specified a function that gives me log likelihood values. In the function, I have several free parameters (the function itself is not linear). I use mle2 to find the maximum likelihood estimators for all free parameters. When I use summary() on the object created by mle2 I get the maximum likelihhod estimators, standard errors, corresponding z-values and Pr(z). My problem: The data I fit the function to consists of repeated choices by multiple participants. This means I have to correct standard errors that are shown by summary() since these standard errors are calculated under the assumption that each choice is independent. From what I read is that I need the sandwich estimator (i.e., Huber) to estimate robust errors. This estimator is implemented in the R-library "sandwich". But, as far as I found out, the library needs an object of the (e.g.) type lm. An object resulting from mle2 cannot be used with the commands of the package. In STATA maximum likelihood estimation with robust standard errors is easily implemented with he command "cluster(id)". Is there something similar in R? Thank you for any advice, Marc Gesendet: Dienstag, 01. Juli 2014 um 10:07 Uhr Von: "Marc Jekel" <feuerwald at gmx.de> An: r-help at r-project.org Betreff: maximum likelihood estimation with clustered data Dear list, I am currently trying to fit free parameters of a model from economics (cumulative prospect theory) using maximum likelihood estimation. I know how to do maximum likelihood estimation using mle or mle2 in R, the problem to which I could not find a solution to is that my data is correlated (i.e., multiple participants with multiple responses) which needs to be accounted for when doing mle. In STATA, mle can be done with clustered data (with the command "ml model ..., cluster(id)") but I could not find an equivalent command in R. More detail (in case someone tried to do the same before): I try to implement an approach proposed by Glenn Harrison who shows in STATA how to implement user-written maximum likelihood estimates for utility functions with clustered data ([1]http://faculty.cbpp.uaa.alaska.edu/jalevy/protected/HarrisonSTATML. pdf). Thank you for any hint, Marc References 1. http://faculty.cbpp.uaa.alaska.edu/jalevy/protected/HarrisonSTATML.pdf