The table below shows the private costs, external costs, and market prices for four different industrial processes.
| Process | Private cost per unit of output (£) | External cost per unit of output (£) | Market price (£) |
|---|---|---|---|
| Process W | 50 | 40 | 82 |
| Process X | 100 | 30 | 109 |
| Process Y | 150 | 100 | 172 |
| Process Z | 200 | 80 | 244 |
Which process, Process W, Process X, Process Y or Process Z, has a market price which takes least account of negative externalities?
Process W
Process X
Process Y
Process Z
