More than a decade in and the U.S. shale boom keeps breaking output records, with fields from Pennsylvania to Texas producing more natural gas than the country needs. That has triggered billions of dollars of investments to ship liquefied natural gas overseas. Yet the U.S. is still importing LNG from places such as Russia and Nigeria. There are two reasons for that: pipeline bottlenecks and the requirements of a 1920 law meant to support a robust U.S. shipping industry.
