paste(character(0), collapse="", recycle0=FALSE) should be ""

Maybe my intuition is just 
different?but when I collapse multiple character vectors together, I 
expect?all the characters from each of those vectors to be in the 
resulting collapsed one.

Yes I'd expect that too. But the **collapse** operation in paste() has 
never been about collapsing **multiple** character vectors together. 
What it does is collapse the **single** character vector that comes out 
of the 'sep' operation.

So

   paste(x, y, z, sep="", collapse=",")

is analogous to

   sum(x + y + z)

The element-wise addition is analog to the 'sep' operation.
The sum() operation is analog to the 'collapse' operation.

H.