The shale energy boom—along with the housing recovery—is an increasingly important pillar of U.S. economic growth, according to a recent report from Standard and Poor’s Rating Services. Regions where drilling is under way benefit the most, but the trickledown effect is widespread.

Just like the often opposite movement of oil and natural gas prices, however, the boom enhances economics for some, but not all. On the bright side, S&P analysts say “the phenomenon of low domestic natural gas prices, which is partly due to the fact that natural gas currently isn’t easily exportable, has helped bring manufacturers and chemical companies back to the U.S.” It’s given the manufacturing sector an edge over overseas competitors. But only an edge—energy makes up a relatively small amount of overall manufacturing costs.

On the downside, natural gas issuers have felt the pinch from low gas prices: S&P has downgraded “a material number of issuers in the oil and gas sector on nearly 40 separate occasions” since January 2011.

The pipeline industry also has suffered. While midstream companies ride the coattails of strong crude prices, solid volume flows and “adequate liquidity positions,” natural gas liquid prices and pipeline transportation rates have fallen.

How is the shale boom driving other sectors’ results? Rail tank car producers and environmental services companies are flourishing. Steel pipe producers are enjoying higher sales. Makers of chemicals, silica and components used in fracing are busy.

The gas boom has enervated manufacturing of compressed natural gas (CNG) powered buses, delivery vans and garbage disposal trucks—as well as makers of engines and components. “Private and public sector operators, mainly in urban and suburban environments, are increasingly adding these vehicles to their fleets—UPS currently uses nearly 1,100 CNG vehicles in the U.S.,” notes S&P.

In the long-distance trucking market, adoption of liquefied natural gas (LNG) as an alternative to diesel is just beginning, and there are barriers—trucks are costly, fueling facilities are sparse. Cummins Inc. and others are making engines for the long-haul 18-wheeler truck market. And UPS plans to expand its 18-wheeler LNG fleet to 700 from 100 this year.

The shale boom has benefited shippers of liquid bulk commodities (crude oil and petrochemicals). And the rating agency has recently upgraded the issues of some North American petrochemical producers because of affordable natural gas.

Who’s been hurt the most by the boom’s lower gas prices? Coal mining, for one, although S&P notes that a recent bump in gas prices makes coal in many basins as economic as gas for utilities. And even though railroads are now carrying lots of crude, the downturn in coal use has hurt freight revenue. Also suffering in the price wars are solar and wind power producers and their manufacturers.

And low gas prices can’t take the primary credit for conversion from coal-fired to gas-powered plants. Instead, tougher government emission standards are boosting use of natural gas by utilities.

The American Chemistry Council says in a recent report that the U.S. chemical industry is on track for a $71.7-billion investment linked to robust and affordable supplies of natural gas from shales. Five years ago, the American chemical industry was the world’s high-cost producer; now it’s among the world’s lowest. Much of the planned investment targets export of chemistry and plastics products, “which could help improve the U.S. trade deficit,” the council says. Also, half of the potential financing is driven by firms based outside the U.S., which suggests the U.S. can capture market share. The council estimates the projects would create more than 530,000 permanent new jobs.

A recent report from KeyBanc Capital Markets Inc. looks for natural gas prices to hold at $4 to $4.50 per Mcf. Why? Natural gas drilling activity hasn’t meaningfully accelerated, the analysts say, and the U.S. onshore active rig count remains down 19% from early 2013 and down 56% from the beginning of 2012. Companies are reluctant to add rigs, with some exceptions: Encana has restarted some drilling in the Haynesville, and Chesapeake is completing/turning to sales previously drilled wells and doing a little drilling in the Barnett, says KeyBanc.

Also supporting current natural gas prices: Gas inventories have been below the five-year average since early April and could remain so through 2013. And, the DOE just approved a second LNG facility, Freeport LNG, to export to countries that don’t have a free trade agreement with the U.S.