"Polyethylene makers, such as Exxon Mobil Corp. and Dow Chemical Co., are enjoying lower costs because higher natural-gas production increases the supply of ethane, a component of natural gas used to make polyethylene. Instead of passing on lower costs to their customers, however, they are reporting fatter profit margins. First-half earnings before interest, tax, depreciation and amortization in Dow's performance plastics division, which makes polyethylene, were up 33% from a year earlier."
You may recall that Dow's CEO, Andrew Liveris a couple year ago wrote a book entitle "Make It In America". It's now pretty clear what the "it" is - not finished goods that consumers and businesses buy, but just the raw materials that go into the finished goods, and most preferably, raw materials from Dow.
Having seen many cycles of resin shortfalls and surpluses, I know the situation will eventually right itself and resin prices will come down, but not until the resin manufacturers have had a chance to make their stash. And see others making money that you were promised can make that "eventually" seem even longer.