How can merit be transferred?

But the persistent Western scholar posed another question: How can merit be transferred to the next life if there is no personality/soul/self?

Thai Answer: The idea of no-self/no-soul is one of the higher doctrines. It may take me many lifetimes to be reborn at a level that would put me in a position to devote myself to contemplating that doctrine full-time. Until then, it is my hope that the merit I make will help me to improve with each rebirth until the final goal is attained — that is, nirvana, after which there is not even any further rebirth.