In 2003, Dr Wilson and Dr. Troy worked with Mass Audubon to estimate the economic value of ecosystem services in the State of Massachusetts. The results of their analysis is reported in Chapter 6 of "Losing ground: at what cost?" In addition to documenting growth trends within Massachusetts, the report measures the economic impact of habitat loss, and includes the first statewide attempt to measure the economic value of "ecosystem services" provided by undeveloped land-such as climate control, water filtration, and flood control.