فضای اقتصادی,ارزش زمین و پایداری: روند پژوهش ارزیابی دارایی واقعی

In the aftermath of the recent boom and bust of US real estate, both a refinement and a deeper understanding of real estate valuation methods have become critical concerns across a number of broad urban-related academic fields. Out of this we see three major trends in the field of real estate valuation research: (1) the expansion of spatial econometrics; (2) the recognition of the differences between land values and improvement values; and (3) acknowledgment of value premiums stemming from more sustainable forms of development. This paper offers a brief summary of the latest work in these emerging areas of academic valuation research.

The academic field of property valuation research crosses many disciplines, and includes not only economics, geography, urban planning and design, but also business, finance, statistics and even specialized real estate departments and schools. As a result, research in the field is often moving in many directions at a single time, as some innovations are following those of the associated disciplines mentioned above while others emanate from the large commercial sector that deals with real estate on a daily basis. Given the dynamic nature of this field, periodic reflections on current developments can offer great insight into the world of academic real estate valuation research. We have identified three separate but related trends in valuation. The first, and perhaps most prevalent, is the increased use of advanced spatial methods in published studies. Second, we see the recent interest in various land value issues, including the focus on land values as a major shaper of both real estate values and of urban spaces in general, as another major trend. The third is the measurement of value premiums offered by energy efficient, sustainable, or green locations and buildings. We address each trend below, followed by a concluding synthesis.

Academic research on real estate valuation is highly dynamic and has capitalized on the recent explosion of cheap computing power and public real estate data. In this paper we have highlighted three prominent trends in real estate valuation; (1) the use of complex spatial modeling techniques; (2) the renewed interest in land values; and (3) the growth in research on the value impacts of sustainable forms of development. The thread that ties all three of these trends together is perhaps the oldest mantra in real estate: location matters. Contrary to the theorizing about how technology would change our need for proximity, the spatial attributes of real estate still remain one of the core concerns of the field. From a methodological standpoint, the emergence of spatial econometrics and related spatially-explicit techniques allow valuation researchers to more completely incorporate the impacts of location into pricing models. These models are necessarily complex and therefore it can be difficult, not only to interpret the results but also to properly specify and estimate them. As the literature suggests, there remains confusion among research practitioners on how exactly to best use these models and what the results of output from the specialized software programs really means for their research question(s). We see the recent articles by Osland (2010) and LeSage (2011) as necessary steps toward increasing the general ease of use and interpretability of these models by non-specialists. The recent boom and bust in the US residential (and non-residential) real estate market has researchers searching for causes. One line of research has been the investigation of the differences between movements in land values as opposed to improvement values in the real estate market. This work is based around the fundamental concept that the drivers of land values differ from those of improvements. For urban policymakers, these findings prove illustrative, since policy decisions most often influence land values, and land uses, whereas the value and form of the improvements are determined by individuals in the private market. One noticeable omission from this literature, however, is the use of the spatial econometric methods discussed above. Given the dependence of land values on locational attributes, this omission speaks to opportunities here for considerable future research on melding these two lines of inquiry. The movement toward environmental sustainability is one of the largest, if not the single largest, cross-disciplinary trend of the last few decades. The real estate discipline is no exception, as sustainable real estate, both in location and in building design, has become a sub-industry on its own--one complete with specialized empirical studies, as discussed above. The work to date is encouraging in terms of supporting the economic value of sustainable development; however, these studies suffer from the same limitations as the land value studies—namely the lack of complex spatial methods in the research designs. As the spatial studies show, failure to adequately account for space can create serious bias in coefficient estimates. While this preliminary work is important to setting the field of green real estate valuation on its way, the lack of spatial econometric analyses sheds some doubt over the robustness of the results. Additionally, while the green valuation literature generally supports the idea that green buildings and location add a price premium, what is missing is a discussion of the costs of building green. If the costs overwhelm the price premiums in the market, profitability is diminished and private market suppliers will have trouble providing the level of green real estate demanded by the market. In sum, we find these three emerging trends in property valuation research as major steps toward a better understanding of the complex operations of urban real estate markets. However, given the slow incorporation of spatially-explicit methods into these emerging fields there remain exciting opportunities for researchers looking to make an impact in real estate valuation. The continued expansion of public data availability and quality, along with increased demand for valuation studies, makes this an exciting time to be working in this field.