# Can effective sample size in MCMC simulation be greater than the actual sample size?

I used coda package's effectiveSize() to find the effective sample size of my MCMC simulation. My effective sample size is greater than the actual sample size, e.g. 9813.626 greater than 9501. I wonder if that makes sense?

My understanding is that the effective sample size cannot be greater than the actual sample size, and will be smaller when there is more autocorrelation.

For a particular definition of autocorrelation, negative autocorrelation can cause $N_{eff} > n$. This answer gives a MWE using coda.