The bad news about below $80 oil

Pisani's market open: Oil, Brazil & European banks

Oil dropped below $80 per barrel on Monday morning, with important implications for production and jobs.

The most important issue for the markets is oil that dips below $80. Today, Goldman Sachs cut its West Texas Intermediate Crude target to $75 from $90. The investment bank also cut crude to $85 from $100.

A few weeks ago Citi put out a report noting that the "full-cycle" costs (land, infrastructure, well drilling and operating costs) for many new shale plays is in the $70 to $80 range. That means that we are entering the area where some new shale plays will become unfeasible.

This has a bigger impact than just lower oil gas prices. Obviously, a lower gas price is good news. The bad news is the potential impact this could have on the other side of the ledger: jobs. The shale oil boom has been a significant help for the jobs market in the United States. A reduction in new drilling could have a significant impact on the booming energy industry.