The difference-in-differences regression model's initial output showed that buyers of single-family residential homes located 2000 and 1000 feet away from existing natural gas pipelines were willing to pay 1% to 3% less, respectively, after the explosion. However, the authors noted that it was challenging to determine whether the impacts were due to perceived or actual risks. Other model specifications did not reveal any significant impact on property values. In conclusion, the study suggested that pipeline risk can have a negative impact on housing market capitalization.
Before the explosion, residential properties had no statistically significant impacts from pipeline proximity for both the Trans Mountain and Olympic pipelines. After the explosion, the Olympic pipeline provided a statistically significant discount for single-family properties located near the pipeline. For homes 50 feet, 100 feet, 200 feet, and 1,000 feet away from the pipeline, the indicated discounts were 4.6%, 2.3%, 1.2%, and 0.2%, respectively. Upon further analysis, the authors observed that the Trans Mountain pipeline had no statistically significant impact after the explosion.
The results of the hedonic analysis showed that land with market awareness of documented contamination sold at an average 67% discount compared to unimpaired prices. Properties adjacent to a contamination source experienced a 42% diminution to land value. The study suggested that unconfirmed, presumed environmental source sites can also have impacted property prices. In this study, suspected contamination source sites had property prices 65% lower than unimpaired land value
The hedonic modeling provided evidence that single-family properties near a blue line and a proposed green line station benefited in the magnitude of 5.7% to 6.8%. After development, proximity to a station was found to be an amenity for both lines. Conversely, homes located near a railway without a station experience a decline in property values, with homes near the green line experiencing diminution five times greater when compared to blue line properties. For multifamily properties, model specifications were poor, and thus no conclusion could be made. Similarly, in terms of “value benefit transfer”, an 18% difference was observed. However, no conclusion could be made due to a lack of precision.
Given that the existing facility produced odor, the incremental impact of the expansion was stated to be small. In reconciliation, the appraiser concluded an overall diminution of 4% for the buildable area of the subject property. For industrial use, the impact was stated to be negative but less than residential in magnitude.
Before public awareness, properties within the potentially contaminated shallow groundwater plume garnered a 242% premium compared to similar unimpaired properties. After public attention, the premium dissipated completely. After listing on the NPL, the hedonic output revealed a considerable discount for properties within the shallow groundwater plume. A 69% to 77% diminution in value was observed for properties within the shallow groundwater plume.  Properties potentially impacted by deep groundwater and surface water contamination did not experience any statistically significant property value diminution in this study.
The results of this study suggest that affordable housing positively affects housing prices and crime rates decrease or essentially stay the same after affordable housing developments are opened. This conclusion contradicts commonly held beliefs about the effects of affordable housing and it is hoped that the study will encourage the development of affordable housing in Orange County.
The hedonic output revealed coefficients of -3% for contaminated homes without GAC filters and -2.3% for homes within the SWCA during the period from 1995 to 2002. However, only the variable for contaminated homes without GAC filters was significant at the 10% significance level. For homes that sold from 2003 to 2006, after the disclosure requirement was enacted, a 7.4% statistically significant diminution in value was observed for homes within the SWCA. In the after-disclosure period, the coefficient for contaminated homes without GAC filters was not statistically significant.
The regression output confirmed that airplane noise had statistically significant negative impact to SFR sale prices in Raleigh. For example, homes located within the 65–70 Ldn noise contour, sold for 5.1% less than unimpaired homes (control area transactions) within the one-mile control group area. Furthermore, homes within the 55–60 Ldn noise contour sold for 2.3% less than unimpaired homes.
Billings and Schnepel’s hedonic output presented evidence that lead-paint remediation had a sizeable positive impact to property values. Furthermore, lead remediated homes sold for approximately $26,270 (32%) more than un-remediated homes. When the authors controlled for home improvements associated with remediation, the estimated benefit dropped to $11,629, and equated to a 160% return on investment for remediation costs.
The hedonic output offered evidence that wildfires provided a negative impact to property values within 10 KM from a burned area. For homes located within 5 KM from a burned area, a 13.7% ($33,232) diminution in value was observed as compared to unimpaired homes. This damage estimate decreased to 7.6% ($18,924) for homes located within 5 to 10 KM from a burned area. Furthermore, the binary variable for view of a burned area revealed an additional $6,600 diminution.