by Steve Hampton and Matt Zafonte
	Updated August, 2005
 
When an oil spill or other pollution event occurs, the  public may be   entitled to compensatory restoration. This does not refer to  attempts   to clean up the impacted site and restore it to its pre-spill    condition; that is primary restoration. Compensatory restoration is   additional  restoration that compensates the public for the interim lost   ecological  services between the time of the incident and full recovery   to pre-spill  conditions.
While there are a variety of economic methods that may be  used   to calculate resource damages, Resource Equivalency Analysis (REA),   also  known as Habitat Equivalency Analysis (HEA) is the most common   method used in  NRDA cases nationwide. This method was developed in the   early 1990s and became  the recommended approach in the Oil Pollution   Act of 1990 (OPA 90) regulations  promulgated by NOAA in 1996. Since   then, REA has been endorsed by the courts on  two occasions. Here, we   provide a brief synopsis of that method, as well as  links and   references to more detailed descriptions and articles about REA.
 REA, we first seek to quantify the injury in terms of degree (% of baseline injured), duration (years until recovery), and size (# of acres, stream miles, birds, etc.). A trajectory estimating the recovery to baseline is also estimated. The injury may be described in terms of lost acre-years or stream mile-years or bird-years of lost ecological services. We then seek to quantify the benefits of a restoration project in similar terms: degree of benefit (e.g., % services per unit area), duration of the project, and trajectory of the benefits over time. With this information, we "scale" the size of the project until the benefit of the project is equal to the injury. The final step is to cost out the project. This cost becomes the measure of damages.
References
	- Dunford, R.W., T.C. Ginn, and W.H. Desvousges. 2004. The use  of habitat equivalency analysis in natural resource damage assessments.  Ecological Economics 48: 49-70. 
- Flores, N.E., and J. Thacher. 2002. Money, who needs it?  Natural resource damage assessment. Contemporary Economic Policy 20(2):  171-178. 
- Hampton, S. and M. Zafonte. 2004. Discounting and  uncertainty in natural resource damage assessments. Poster. Fourth SETAC World  Congress, November 14-18, 2004,  Portland, OR 
- Hampton, S. and M. Zafonte. 2003. Calculating compensatory  restoration in natural resource damage assessment: Recent experience in California. Proceedings of the California World   Ocean ’02 Conference, October 2002,  Santa Barbara, CA  PAPER AVAILABLE HERE
- Helton, D. and T. Penn. 1999. Putting response and natural  resource damage costs in perspective. Proceedings of the 1999 International Oil  Spill Conference. 
- Jones, C.A.  and K.A. Pease. 1997. Restoration-based compensation measures in natural  resource liability statutes. Contemporary Economic Policy 15: 111-122. 
- King, D.M. 1997. Comparing ecosystem services and values  with illustrations for performing Habitat Equivalency Analysis. Prepared for  NOAA. Silver Spring, MD.  PAPER AVAILABLE ONLINE
- Mazzotta, M.J., J.J. Opaluch, and T.A. Grigalunas. 1994.  Natural resource damage assessment: The role of resource restoration. Natural  Resources Journal 34: 153-178. 
- NOAA. 1995. Habitat Equivalency Analsyis: An Overview.  Policy and Technical Paper Series, No. 95-1, (Revised 2000 and 2006). 
- NOAA. 1999. Discounting and the treatment of uncertainty in  natural resource damage assessment. Technical Paper 99-1. 
- Penn, T., and T. Tomasi. 2002. Calculating resource  restoration for an oil discharge in Lake Barre,   Louisiana, USA. Enivornmental Management 29(5): 691-702. PAPER AVAILABLE ONLINE
- Sperduto, M.B., S.P. Powers, and M. Donlan. 2003. Scaling  restoration to achieve quantitative enhancement of loon, seaduck, and other  seabird populations. Marine Ecology Progress Series, 264:221-232. 
- United States  v. Fisher, 977 F. Supp 1193 (D.D. Fla 1997) 
- United States  v. Great Lakes Dredge and Dock Co., No. 97-02510-CIV-EBD, 1999. 
- U.S. Dist. LEXIS 17612 (S.D. Fla. Sept. 27, 1999), aff’d,  259 F.3d 1300, 1305-06 (11th Cir. 2001). 
- Unsworth, R.E., and R.C. Bishop. 1994. Assessing natural  resource damages using environmental annuities. Ecological Economics 11: 35-41. 
- Zafonte, M. and S. Hampton.  2007. Exploring welfare implications of resource equivalency analysis in  natural resource damage assessments. Ecological Economics 61: 134-145
- Zafonte, M. and S. Hampton.  2005.  Lost bird-years: Quantifying bird injuries in natural resource damage assessments for oil spills, Proceedings of the 2005 International Oil Spill Conference, May 15-19, 2005, Miami, FL.