The Financial Post reports in its Wednesday edition that dockworkers at every major port on the U.S. East and Gulf coasts have gone on strike, which could have significant impacts on the economy and politics just weeks before the presidential election. A Bloomberg dispatch to the Post reports that the affected ports handle about half of all United States trade volumes, and the strike will stop container cargo and auto shipments. However, energy supplies and bulk cargo will not be affected. There will be some exceptions to allow for the movement of military goods and cruise ships. This strike follows a three-day strike at the Port of Montreal on Monday. The impact of a work stoppage at every major container port from Houston to Miami and New York-New Jersey depends on how long the strike lasts. JPMorgan says the economic loss from the shutdown, which began at 12:01 a.m. Eastern Standard Time on Tuesday, will be between $3.8-billion and $4.5-billion a day. Grace Zwemmer at Oxford Economics estimates that it would take about a month to clear the backup resulting from a week-long strike. The International Longshoremen's Association is seeking higher wages and a rollback of the language on automation in six-year contract.