اثرات رونق گاز طبیعی بر اشتغال و درآمد در کلرادو، تگزاس، و وایومینگ

Improvements in technology have made it profitable to tap unconventional gas reservoirs in relatively impermeable shale and sandstone deposits, which are spread throughout the U.S., mostly in rural areas. Proponents of gas drilling point to the activity's local economic benefits yet no empirical studies have systematically documented the magnitude or distribution of economic gains. I estimate these gains for counties in Colorado, Texas, and Wyoming, three states where natural gas production expanded substantially since the late 1990s. I find that a large increase in the value of gas production caused modest increases in employment, wage and salary income, and median household income. The results suggest that each million dollars in gas production created 2.35 jobs in the county of production, which led to an annualized increase in employment that was 1.5% of the pre-boom level for the average gas boom county. Comparisons show that ex-ante estimates of the number of jobs created by developing the Fayetteville and Marcellus shale gas formations may have been too large.

Improvements in drilling technology have made it profitable to exploit unconventional gas reservoirs in relatively impermeable media. In part because of the greater feasibility of tapping these new reservoirs through hydraulic fracturing – shooting a mix of water and chemicals into the formation – the Potential Gas Committee recently increased its estimate of gas reserves in the U.S. by 35%, the largest increase in the 44 year history of the committee's report (Colorado School of Mines, 2009). Long term projections of high energy prices suggest that the natural gas industry will have a persistent and growing influence on the economy in the many areas of the U.S. with large gas reservoirs.1 Substantial gas exploration is occurring in Pennsylvania (Marcellus Shale Formation) and production has already spiked in Arkansas (Fayetteville Shale Formation) where gas production increased by 2.5 times from 2007 to 2009 (Energy Information Agency, 2011). Growth is expected to continue with Chevron, Exxon Mobile, and Royal Dutch Shell investing heavily in developing the Marcellus Shale (Kaplan, 2010). The trends emerging in Pennsylvania and Arkansas started earlier and are more mature in Colorado, Texas, and Wyoming where gas production increased markedly from 1999 to 2008 (Fig. 1). Over the same period, wellhead prices more than doubled. The combination of production and price increases imply that the value of gas produced in each state more than quadrupled in less than a decade – clear evidence of a boom in natural gas (Table 1).Estimates of the economic gains to local economies from a boom in natural gas extraction can inform policy makers considering how much incentive to provide (or disincentives to remove) to encourage extraction. The magnitude of gains is especially important for unconventional gas as it must be considered in light of possible negative externalities associated with extraction, including deterioration of roads caused by heavy trucks transporting water and possible health and environmental consequences from hydraulic fracturing. Some have used input–output models to project how gas development and extraction will affect local and state economies (Center for Business and Economic Research, 2008 and Considine et al., 2010), however, the results of the models hinge on assumptions about economic multipliers and may deviate substantially from actual effects. To my knowledge, this is the first study to empirically estimate the local employment and income effects from the large expansion in natural gas extraction in several U.S. states in the last decade. In addition to studying aggregate economic outcomes, I explore how economic gains are distributed among the local population – a topic of interest since gains from extractive resource booms are sometimes skewed away from the poor (Brabant and Gramling, 1997). I use gas deposit and production data combined with economic data to estimate how a substantial increase in the value of gas production from 1998/99 to 2007/08 affected total employment, total wage and salary income, median household income, and poverty rates in the county of production in Colorado, Wyoming, and Texas. The empirics, which control for long-term growth trends and the potential endogeneity of gas production, provide the first ex-post analysis of the number of local jobs created by expanding gas production and are compared to ex-ante projections of the jobs created by developing the Fayetteville and Marcellus shale gas formations.

This study's ex-post analysis of a gas boom in Colorado, Texas, and Wyoming can inform policy debates in states where gas production is beginning to expand. As noted in the Introduction, the Marcellus Shale covering large parts of Pennsylvania and New York is in the early stages of development, with production in a few counties approaching substantial levels. In the current economic and political context of high unemployment and large public sector deficits, more jobs and greater tax revenue from exploiting natural gas resources appeals to political leaders and their constituents. Though estimated for more thinly populated western counties, the absolute number of local jobs created per million dollars in gas production (2.35 jobs) provides a reference point for policy debates in states with growing natural gas industries. The ex-post estimates from Colorado, Texas, and Wyoming can complement ex-ante economic analysis using input–output models, which in the case of the Fayetteville and Marcellus shale may overestimate the number of jobs created by greater gas production. Defensible estimates of employment and income gains can complement other indicators relevant to policy debates involving natural gas extraction. A comprehensive assessment of the costs and benefits of gas extraction would consider public and private economic benefits and costs, including economic, health, and environmental costs associated with extraction. Costs to consider include fixing roads damaged by greater use (National Park Service, 2009) and decreased property values in some areas Boxall et al. (2005). Perhaps more importantly, injecting a water-chemical mix into the ground to ‘frack’ unconventional deposits may involve costs that are not yet clear. Injected water that returns to the surface must be properly managed, and waste water treatment plants designed without such waste in mind may be unable to handle fluids from gas operations (Massachusettes Institute of Technology, 2011 and Yoxtheimer and Gaudlip, 2011). Defensible estimates of costs combined with measures of economic benefits can inform policy debates like whether and how much state governments should tax gas extraction.