Working Paper: NBER ID: w31390
Authors: M. Scott Taylor; Fruzsina Mayer
Abstract: Orcinus Orca is the world’s largest predator, and simultaneously a significant tourist asset and cultural icon for much of the Pacific Northwest. In the past two decades, the Southern Resident Killer whale (SRKW) population has declined by more than 25 percent, putting them at risk of extinction. The cause of this decline is hotly debated. This paper employs novel data, an innovative noise pollution model, and quasi-experimental methods borrowed from environmental economics to solve this puzzle. We find consistent evidence that vessel noise pollution from international shipping has lowered fertility and raised the mortality of the SRKW significantly. Had noise pollution remained at its pre-1998 levels, the SRKW population would be 30% larger. Noise pollution is a growing threat to marine mammals worldwide.
Keywords: No keywords provided
JEL Codes: F1; Q01; Q20; Q53
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| increased vessel noise (R41) | reduced fertility rates (J13) |
| increased vessel noise (R41) | increased mortality rates (I12) |
| noise pollution at pre-1998 levels (Q53) | SRKW population 30% larger (L94) |
| increased vessel noise (R41) | SRKW population decline (Q50) |
| quasiexperimental variation in noise pollution (C99) | causal link to health outcomes (I14) |
| noise shocks (R41) | independent variation in exposure (C29) |