People that worry about the peaking of global oil supplies often use symmetrical curves as simple models for how production will peak and then decline, with logistics and Gaussians being popular choices. This goes back to M. King Hubbert (and I’ve done some of this myself). The United States is the poster child for this kind of analysis, since this region was the first to be developed at scale and production peaked in 1970. However, it seems increasingly clear that the US production curve is far from symmetrical (perhaps driven by higher prices since the 1970s, and especially in the 2000s). Using data from the EIA for production and reserves, we can see that the decline side is slower than the growth side for both.