Paul Humphreys - How Properties Emerge (1997)
The goal of Humphreys' paper is to coherently formulate a generalised position that does not fall prey to two key problems for mental causation: the exclusion argument (PDF) and Kim's downward causation problem. The solution is to create a logical "fusion" operation which, by creating compounds of micro-level properties, is proposed as the actual source of emergence (not the instantiation of the micro-level base). This also serves to resolve the problem of downward causation by giving us chains of causal couples which always begin and end at the base level, through potentially mediated through higher-level causal structures.
Again, however, this gives us a coherent metaphysical possibility, without very much real-world meat. Humphreys hazards quantum entanglement as one potential example, but concludes that the jury is still out.