Cavailhes J. GIS Based Hedonic Pricing of Landscape 2009

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    Environ Resource Econ (2009) 44:571590DOI 10.1007/s10640-009-9302-8

    GIS-Based Hedonic Pricing of Landscape

    Jean Cavailhs Thierry Brossard

    Jean-Christophe Foltte Mohamed Hilal

    Daniel Joly Franois-Pierre Tourneux

    Cline Tritz Pierre Wavresky

    Accepted: 16 June 2009 / Published online: 27 June 2009 Springer Science+Business Media B.V. 2009

    Abstract Hedonic prices of landscape are estimated in the urban fringe of Dijon (France).

    Viewshed and its content as perceived at ground level are analyzed from satellite images

    supplemented by a digital elevation model. Landscape attributes are then fed into economet-

    ric models (based on 2,667 house sales) that allows for endogeneity, multicollinearity, and

    spatial correlations. Results show that when in the line of sight, trees and farmland in the

    immediate vicinity of houses command positive prices and roads negative prices; if out of

    sight, their prices are markedly lower or insignificant: the view itself matters. The layoutof features in fragmented landscapes commands positive hedonic prices. Landscapes and

    features in sight but more than 100300 m away all have insignificant prices.

    Keywords Amenity Hedonic pricing Landscape View

    1 Introduction

    Rural scenery, open spaces, woodland, and farmland are green landscapes sought after by

    many households in most developed countries. This paper focuses on the valuation of the

    viewshed and its contents, as seen by residents from their homes, in a French leafy periur-

    ban belt. This is an important issue because public authorities are wary of urban sprawl and

    careful in the management of open spaces and green areas in and around cities.

    This research was financed by Burgundy Regional Council, Cte-dOr Departmental Council and Dijon

    Conurbation Joint Councils. It uses data on real-estate transactions from the PERVAL Corporation.

    J. Cavailhs (B)

    CESAER-INRA, 26 Bd Docteur Petitjean, BP 87999, 21079 Dijon Cedex, Francee-mail: [email protected]

    T. Brossard J.-C. Foltte D. Joly F.-P. Tourneux C. Tritz

    CNRS-ThMA, 32 rue Megevand, 25030 Besanon, France

    M. Hilal P. Wavresky

    INRA-CESAER, 26 Boulevard Petitjean, BP 87999, 21079 Dijon Cedex, France

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    572 J. Cavailhs et al.

    Hedonic pricing is employed here to value landscapes in a periurban belt around Dijon, the

    main city in Burgundy (France). These are commonplace rural landscapes, with villages and

    small towns scattered over plains, hills, and valleys covered by farmland and woodland. We

    analyze a landscape as seen from within instead of from above by allowing for objects

    and relief that may block out the view. The view from home can thus be reconstituted in athree-dimensional space, allowing us to identify both landscape objects (trees, fields, roads,

    etc.) present in the viewshed, and the same objects that are present in the surroundings but

    hidden by masks. Hedonic prices of these seen and unseen objects are then derived from

    data for 2,667 house sales using either a fixed-effects model estimated by the instrumental

    variable method or a random-effects model.

    The remainder of the paper is arranged into four parts. After a brief review of the literature

    (Sect. 2), the economic and geographic models are set out along with the data (Sect. 3); then

    come the results (Sect. 4). Section 5 presents the discussion and conclusions.

    2 Landscape Valuation

    Econometric landscape valuation presupposes that quantitative landscape variables are intro-

    duced into econometric models. Different methods or models such as they are developed by

    geographers for characterizing landscape are appropriate and can be used to this end. We

    present some examples here arranged according to the type of material: ground-level photo-

    graphs to mark the esthetic value of landscape, maps to measure distances between objects

    (1 dimensional approach), aerial photographs or satellite images to classify the land cover

    or calculate landscape indices (2 dimensional approach), virtual landscapes reconstructed in

    three dimensions, as is done here, by combining satellite images and digital elevation models.Photographs have long been used to analyze the esthetic value of landscapes by regression

    methods. A score given by a panel is explained by objective attributes (land cover, visual

    arrangement, etc.), subjective attributes (mystery, atmosphere, etc.), and sometimes personal

    characteristics (gender, age, etc.). Much of this work was done in the 1980s. Gobster and

    Chenoweth (1989) listed more than 80 references and recorded 1194 terms for describing

    esthetic preferences. For example, marks for photographs in the Great Lakes region (US)

    are explained by physical, ground-cover, informational (order, complexity, mystery), and

    perceptual (open, smooth, easy to cross) variables (Kaplan et al. 1989). Recent research has

    followed similar lines; for example, Johnston et al. (2002) use maps and photographs to show

    that households choose fragmented, long and narrow housing subdivisions when density islow, but opt for more clustered forms for denser subdivisions. Ground-level photographs are

    also used to estimate the economic value of landscapes by contingent evaluation (e.g. Willis

    and Garrod 1993) or by the choice-experiment method (Hanley et al. 1998).

    Distance between an observer and an object is used as a landscape variable. Real-estate

    values generally decrease with distance to green areas, golf courses, forest parks ( Tyrvinen

    and Miettinen 2000), stretches of water(Spalatro and Provencher 2001)ortowetlands(Mahan

    et al. 2000). This effect is sometimes non-linear. For example, Bolitzer and Netusil (2000)

    show that the proximity of open or green spaces affects house prices when the distance is

    very short (a few tens of meters), but the effect falls off rapidly with distance, and disap-pears beyond a few hundred meters at most. Thorsnes (2002) shows that housing with direct

    access to forests is worth 2025% more, but that this extra value vanishes if there is a road

    to cross to get to the forest. Therefore, researchers must take into account the exact locations

    of observers and objects alike.

    The land cover within a radius around a house can be analyzed from aerial photographs

    or satellite images. The findings are used for landscape valuation, mostly by the hedonic

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    GIS-Based Hedonic Pricing of Landscape 573

    method. In most although not all cases positive hedonic prices are reported for trees (Kestens

    et al. 2004), particularly on land adjacent to the residential lot (Thorsnes 2002), and for

    nearby recreational woods (Tyrvinen and Miettinen 2000) as well as for parkland, golf

    courses, or greenbelts. Farmland has a less clear-cut impact with some studies concluding it

    has a positive effect on real-estate values (Roe et al. 2004, who use the choice-experimentmethod) and others reporting contrary effects (Garrod and Willis 1992). The legal status of

    land is sometimes included in the hedonic equation either because it affects expectations

    about development (Irwin 2002) or because access rights to parcels affect their recreational

    value (Cheshire and Sheppard 1995).

    Landscape ecology provides variables for characterizing the shape of patches formed

    by the land cover: diversity, fragmentation, entropy, fractal dimension, or other statistical

    summaries. For example, Geoghegan et al. (1997) show that landscape fragmentation and

    diversity have negative effects on real-estate values, except where very close to and very far

    from Washington DC.

    The view from the ground entails integrating the third dimension (i.e. relief and any tall

    objects) into 2D satellite images. It has only recently been introduced into hedonic-valuation

    models: to the best of our knowledge, there are just a few examples to date. Germino et al.

    (2001) analyze a landscape from satellite images and a digital elevation model to simulate a

    view, and Bastian et al. (2002) use such variables for the hedonic pricing of landscape; they

    conclude that in the Rocky Mountains (US) landscape diversity, the only landscape variable

    that is significant, is highly appreciated. Paterson and Boyle (2002), using precise satellite

    imagery information, compare the land cover and the view from the ground in a rural region

    of Connecticut (US). The sign of their results varies with the specification, showing that

    the visibility measures are important determinants of prices and that their exclusion maylead to incorrect conclusions regarding the significance and signs of other environmental

    variables (Paterson and Boyle 2002: 417). Here, we extend and enhance this conclusion by

    distinguishing between objects in view and objects hidden by relief or masks that block the

    view. Lake et al. (1998) estimate the price of road noise and view in Glasgow (Scotland);

    the viewshed is identified by systematic visits (to measure building heights), and the findings

    show that the view of a road reduces the real-estate price. In the same way, we distinguish

    seen from unseen roads.

    In short, most studies use data on distance (1D), and maps, aerial photographs, or satellite

    images (2D). Very few reconstruct 3D landscapes as is done here by taking account of relief

    and tall objects that block the view. Our method allows us to evaluate the hedonic price ofobjects whether in or out of sight, by using hedonic pricing models. We take into account

    both endogeneity of covariates and spatial autocorrelation by using a fixed-effects model

    estimated by the instrumental method, and a random-effects model.

    3 Study Region, Geographical and Econometric Models, Data

    3.1 The Study Region

    The study region is a belt around Dijon (France). Its inner bound is the city of Dijon and its

    suburbs, which are excluded from the study. Its outer bound is given by access time to Dijon

    of less than 33 min or a distance by road of less than 42 km.1 The region covers 3,534 km2

    1 These limits were determined by first setting a threshold of 40% of commuters, and then rounding by

    including some interspersed communes.

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    Fig. 1 South-eastern sector of the study region

    and has 140,703 inhabitants. It is composed of 266 communes (a commune is the lowest tier

    of local government in France), with a mean population of 461 inhabitants (median: 229,

    standard deviation: 733). Land cover is 2.4% built areas, 59% farmland, and 38% forests and

    natural formations.

    Figure 1 shows the settlement pattern in the south-eastern sector of the study region (other

    quadrants are similar). This region is made up of many villages and small towns forming

    densely populated clusters isolated from their neighbors by broad expanses of farmland,

    woods, and forests. The average population density of villages is 1700 inhabitants per square

    kilometer when population is divided by the area of the village polygon (composed of build-

    ings, streets and roads, and open and green spaces whether private or public); but the mean

    population density of the study region is only 41 inhabitants per square kilometer. Clearly,

    two different scales co-exist: dwellings are tightly clustered (just a few tens of meters apart)

    within villages, while villages lie several kilometers apart. Moreover, from one commune to

    the next there are often stark variations in population, household income, local public policy

    (tax, land zoning), quality of schools, etc.

    3.2 A GIS-Based Geographic Model of Quantitative Analysis of Landscape

    A landscape can be quantified in terms of its extent and its content, which are analyzed here

    using a GIS-based model (see a survey in Bateman et al. 2002). Its extent varies with both

    relief and the objects that may block the view. Its content is a matter of the type of objects

    visible. The viewshed is measured by simulating the view of an observer whose eyes are 1.8 m

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    Fig. 2 Viewshed without and with objects blocking the view. (A) There is an uninterrupted view from 0 to155m from the observer located at cell I; between 155 and 325 m the view is blocked by the hill-crest. Thesecond hill is visibile between 325 and 385 m. (B) The tree 65m from the observer blocks out the view beyond

    above ground level. This simulation of view is made everywhere, all around each observation

    point of the study region. Each place in the surroundings is visible or not, depending upon

    topography and land-use structure (Fig. 2). This process operates using a cellular represen-

    tation of space: a squared grid divides the study area into regular cells (7 7 m = 49 m2),

    which are the smallest spatial units for identification of geographical objects.

    The distance from the observer to the seen objects is measured by distinguishing six radius

    areas to take into account the depth of the viewshed: 070, 70140, 140280, 2801200 m,

    1.26, and 640 km. Figure 3 shows this process applied to a flat area: Fig. 3a illustrates the

    land use and 3-B shows the viewshed from the central point, containing different land-use

    types located at different distances. On average, only 18% of the land cover can be seen from

    the ground (the median is 8.9%).

    To analyze views in this way, a land-cover layer that localizes and identifies objects is

    combined with a digital elevation model that processes topography (see Joly et al. 2009).

    Land-cover data are derived from two satellites: Landstat 7 ETM (Enhanced Thematic Map-

    per; 30 m and 15 m spatial resolution) and IRS 1 (Indian Remote Sensing; 5.6 m spatial

    resolution). The model is based on the state of the landscape at the time the satellites passedoverhead (June and September 2000). The economic data cover the period 19952002. The

    landscapes changed little over this period, so satellite images from 2000 can be used.2

    2 The European database Corine Land Cover (CLC) provides two satellite images in 1990 and 2000, from

    which the land use change between the two dates can be calculated. The resolution of CLC is too coarse to

    be used in our study but it shows that the change in land use in the study region has been slow. Moreover, the

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    Fig. 3 Land cover (a) and view at ground level (b)

    Figure 3a illustrates the land cover in three rings around a transaction point. This point

    is located in a village where two roads intersect and around which the built environment

    is relatively tight-knit, even if some open spaces form gaps. Outside the village, the area is

    covered by crops alone. The entire space is taken into account. Figure 3b shows the viewshed.

    The space is subdivided into seen or masked sectors, where only the cells actually seen by

    the observer are filled out (in grey or black). They make up just 12% of the area of the 280 mradius ring. A substantial difference arises between the area of the ring and the area seen,

    because of topographical masks and land cover that hide more of the view the closer they

    are to the observer. We term unseen object the difference between the total number of land

    cover cells and the total number of cells seen.

    Images are then processed by standard remote sensing procedures to correct their geom-

    etry, merge the two satellite images, and classify the pixels, which correspond to the cells.

    Twelve types of land cover are identified: conifers and deciduous trees (merged as trees);

    crops, meadows and vineyards (merged as agriculture); bushes; roads and railroads (merged

    as networks); built cells; water; quarries; and trading estates. Some objects are ascribed afixed height imposing a visual mask: 15 m for deciduous trees, 20 m for conifers, 3 m for

    bushes, 1 m for vineyards and 7 m for houses.3 The others land uses (water, roads, railroads,

    fields) have zero height.

    3.3 Econometric Model

    We begin with the usual hedonic price equation: ln Pi = Xi b + i , where Pi is the price

    of real-estate i , Xi the matrix of explanatory variables (including an intercept), b the vector

    Footnote 2 continuedeconometric model estimated for 20002001 yields results that are statistically similar to those obtained over

    the whole period.

    3 The model may be sensitive to the height of the houses, which are the most common type of object blocking

    the view. They are mainly detached houses without upper storeys. We tested the effect of the chosen height

    (from 5 to 9 m) on the econometric results; they are not statistically different between 6 and 9 m. The height of

    constructions is very variable in the city of Dijon and its suburbs, where there are many apartment buildings;

    for this reason the city was excluded from the study region.

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    of parameters to be evaluated, and i an error term.4 We examine in turn the questions of

    endogeneity, spatial correlation, and multicollinearity (see a detailed discussion related to

    these questions in Irwin 2002).

    First, covariate endogeneity may have several causes: when the consumer chooses simul-

    taneously the price of housing and the quantity of an attribute (e.g. the living space); whenthe market determines both the l h.s. and some r.h.s. variables of the equation (e.g. if urban

    pressure is high, residential values are high and open spaces are scarce; conversely, the scar-

    city of open spaces influences residential prices; Irwin 2002); when omitted variables are

    correlated with variables present in the equation. Thus, the instrumental variable method

    (IV) is employed here. We use as instruments either personal features of the agents (Epple

    1985; Sheppard 1999) or other instruments for projecting endogenous landscape variables

    (See Sect. 3.4). If endogeneity occurs, the main equation is then estimated by the 2SLS.

    Second, for a located good such as housing, spatial dependency is often present because

    nearby observations share more similarities than observations which are far apart. Moreover,

    located data are often spatially heterogeneous, which entails spatial heterogeneity of the esti-

    mators for different zones. These two aspects may be addressed by means of spatial fixed

    effects. This rests on the assumption that the spatial range of the unobserved heterogeneity/

    dependence is specific to each spatially delineated unit (Anselin and Lozano-Garcia 2008).

    Following this method, we introduce into the equation a variable m j characterizing the

    commune j : ln Pi j = Xi j b+bj m j + i j that captures the effects of attributes whose values

    are shared by observations located in this commune, including badly measured or omitted

    variables, to the extent that the effect of these covariates is identical for each house within

    the commune, and may be appropriately modeled by a linear shift in the model intercept.

    Thus, there are no inter-commune correlations between the residuals.5

    The m j s are eitherfixed-intercept shifters in the fixed-effects model (m j = Ij ), or random-intercept shift-

    ers in the random-effects model (m j = j ). The fixed-effects model is better at handling

    omitted or poorly measured variables, but it fails to take account of inter-commune effects.

    The random-effects model allows us to introduce additional explanatory variables (e.g. inter-

    commune differences between landscape variables), but it involves a risk of bias if some

    inter-commune variables are badly measured, and some Xi j s may be correlated with the j s.

    Therefore, we prefer the fixed-effects model. Even so, the random-effects model is also used

    to check effects of inter-commune landscape variables and to compare the results obtained

    by the two approaches.

    Spatial autocorrelation may also occur because of the location of the houses in a commune.A Morans index between the neighbors i j s is computed and its significance is tested.

    6

    Thirdly, multicollinearity between landscape variables is an important issue, because the

    land-cover types may be correlated for several reasons: complementarity, such as between

    roads and houses, dominant uses (e.g.: farmland occupying the main part of an alluvial plain

    and limiting the space available for other uses), the same land-cover should be present on

    both sides of two adjacent rings. Fortunately, as Pearsons correlation coefficients show, the

    view from the ground reduces these spatial links, because high objects block the view in a

    quasi-random way, and break the regular pattern of land uses. We chose the view from the

    ground because it is the actual view, and this choice entails the statistical advantage of greatly

    4 The result of a Box-Cox test supports the use of the log-linear form.5 A Morans index test for observations belonging to neighboring communes allowed us to check this is indeed

    the case.6 We use a contiguity matrix where observations less than 200 m apart are neighbors. This distance is the

    threshold used in France to define urban morphology (distance cut-offs of 50 and 100 m were also tested).

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    reducing multicollinearity. Nevertheless, multicollinearity may subsist, and is managed by

    standard methods: merging of adjacent rings when a landscape variable exhibits a high corre-

    lation and yields similar parameters on both sides; transformation of other correlated variables

    (variables introduced as a percentage of a viewshed, etc.).

    Finally, the statistical tests are carried out as follows: Hausmans method is used to testwhether variables are endogenous (by the increased regression method); Sargans method

    is used to test the validity of the instruments; two Morans indexes between neighboring

    residuals are calculated (houses less than 200 m apart and houses belonging to neighboring

    communes) and their significance is tested; the homoscedasticity of the residuals is submitted

    to Whites test.7

    3.4 Data and Variables

    Data were collected from real-estate lawyers (notaires), who are responsible for registering

    real-estate conveyances in France. The database is made up of 2757 sales of detached housesbetween 1995 and 2002, and records the price of the transaction and certain characteristics

    of the property and the economic agents involved.8 Each observation is also characterized

    by its longitude and latitude in a French system of Cartesian coordinates (the Lambert

    system), allowing a link with the geographical data. Some 90 observations were excluded

    (atypical observations, shortcomings of the data base, etc.): evaluations were made from

    2,667 observations. The variables used in the regressions are defined in Table 1.

    Three variables, closely correlated with the living space (lot size, number of rooms and of

    bathrooms), were transformed into lot size/living space, average room size (also included in

    quadratic form), and number of bathrooms/living space. New houses resold within 5 years

    have specific characteristics, which are captured by a dummy variable. Some of the vari-

    ables in the database were excluded because either of insignificant parameters (presence of

    outbuildings, parking spaces, cellars, lofts, terraces or balconies) or subjective appreciation

    by the notaire (quality of the structure, etc.). Other variables characterize the transaction

    (operator, previous transaction, house occupied or not, remoteness of the buyers previous

    residence), the location (proximity to a highway, location both in the zoning scheme and a

    floodable zone, distance from the town hall), the topography of the parcel (slope, orientation,

    steep-sidedness), and the year of the transaction (dummy variables that take into account

    inflation, interest rate, tax policy, etc.). The database also includes variables used as instru-

    ments to project characteristics of the house that may be endogenous: the gender, occupation,age, marital status, and nationality of the buyer and the seller. Other instruments were used

    to project landscape attributes that may be endogenous: Percentage of Like-Adjacence, Con-

    tagion Index, Interspection and Juxtaposition Index, Division Index, Perimeter-Area Ratio

    Distribution, Simpsons Evenness Index, and Patch area mean (McGarigal et al. 2002).

    The landscape variables are made up of the number of cells seen and unseen (i.e. the dif-

    ference between the land cover and the seen cells) arranged in the six rings (some variables in

    adjacent rings are merged). They are computed for an observation point located at the center

    of the residential lot. However, the view may change within the size of the parcel; therefore

    we have checked that the econometric results are not influenced by the lot size.9 We tested

    7 Other problems occur in the second stage of the Rosen (1974) method (Brown and Rosen 1982; Day et al.

    2007), which we do not examine because this second stage cannot be made here.

    8 This data base contains only houses that were sold, with no telling whether or not they are representative of

    the housing stock as a whole.9 We estimate the econometric model by calculating the average view over a square around every observation

    point with sides of 3, 5 or 9 cells, depending on whether the area of the residential lot, recorded in the data base,

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    Table 1 Variables

    Abbreviation Definition

    LSPACE Living space (m2) (logarithm)

    LOT/LSPACE Lot size (m2)/living space (m2)

    ROOMSIZE Average room size = living space/number of main rooms

    (ROOMSIZE)2 Average room size: square form

    STORIES Number of stories in the house (included habitable attic or basement)

    BATHROOMS Number of bathrooms/living space

    ATTIC Presence of an attic

    PERIOD OF Period of construction: before 1850; 18501916; 19171949;

    CONSTRUCTION 19501969 (reference); 19701980; 19811991; 19922002; unknown

    LESS 5 YEARS Building constructed since less than 5 years, and reselled

    BASEMENT Presence of a basement

    AN1995 to AN2002 Date of conveyance: dummies from 1995 to 2001 (2002 = reference)

    PRIVATE Transaction without real estate offce (directly between private individuals)

    SALE OFFICE Transaction by a real estate office

    LAWYER OFFICE Transaction by a real estate lawyer office

    BUYER OCC Property already occupied by the buyer

    SELLER OCC Property already occupied by the seller

    DIST BUYER Distance between the house and the buyers location (logarithm)

    FRENCH Buyer of French nationality

    SUCC Previous transaction = succession

    DIVISON Previous transaction = division of estate

    NORMAL SALE Previous transaction = normal sale

    100_200_ROAD 100200 m from a major road

    POS-UD Zone UD of the zoning scheme, i.e. located on periphery of the village

    MIXED ZONE Mixed zone of the zoning scheme: residential and business zone

    DIST TOWN HALL Distance to the town hall from a transaction point

    SOUTH South orientation of the parcel

    FLOODING Liable to flooding

    STEEP Steep sidedness

    POPULATION Population of the commune

    DISTANCE DIJON Distance to Dijon from the town hall of a commune

    (DISTANCE DIJON)2 Distance to Dijon from the town hall of a commune: square form

    INCOME Mean income of the commune households

    TREE Number of tree-covered cells (R_TREE: rate of these cells)

    TREE LOT/LSPACE Number of tree-covered cells LOT/LSPACE

    AGRI Number of cells of agriculture (R_AGRI: rate of these cells)

    AGRI LOT/LSPACE Number of cells of agriculture LOT/LSPACE

    AGRI POSUD Number of cells of agriculture class UD of the zoning scheme

    NETWORK TRANSPORT Number of cells of road/railroad (R_NETWORKS: rate of these cells)

    BUILT Number of built cells (R_BUILT: rate of these cells)

    BUSH Number of cells of bush (R_BUSH: rate of these cells)

    WATER Number of cells of water

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    Table 1 continued

    Abbreviation Definition

    DECID_PACHES Number of patches of deciduous trees within a 70 m radius

    DECID_EDGE Length of deciduous wood edges within a 70 m radius (m)AGRI_PACHES Number of patches of crops between 70 and 140 m

    COMPACT Compactess index (0 = compact forms; 1 = elongate forms),

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    In the fixed-effects model, the adjusted R2 is 0.70; the 2 Log Likelihood is 671.4 in

    the random-effects model. Some 35% of the intercept shifters are significant at the 5% level

    in the fixed-effects model, and the random intercepts are significant at the 1% level in the

    random-effects model (z-value equals 5.34). The living space is endogenous (Students t

    in the increased regression is 13.7) and Sargans test shows that the characteristics of theagents used as instruments are exogenous. Thus, the main equation is estimated by the 2SLS,

    using as covariate the projection of the living space on the instruments. Whites test shows

    that the residuals are homoscedastic. Morans index between residuals of houses less than

    200 m is 0.015, and between residuals of houses pertaining to neighboring communes is

    equal to 0.008661. These values are insignificant, which suggests statistically insignificant

    effects of spatial autocorrelation, both at the inter-commune and the intra-commune levels.

    Regarding the landscape variables, the first finding is that, unlikein other studies (e.g. Irwin

    2002; Irwin and Bockstael 2001), landscape attributes are not endogenous.10 The difference

    probably arises from stringent public control of land cover in France that limits the market

    forces. Moreover, in the absence of spatial autocorrelations and with landscape covariates

    being exogenous, the tests do not allow us to conclude that landscape estimates are biased

    by omitted variables.

    The significance, sign, and magnitude of the parameters estimated by the fixed-effects

    model using the 2SLS and by the random-effects model are different regarding some char-

    acteristics of the house and of the transaction (area of the rooms, date of construction, etc.).

    Signs for landscape variables are always the same whatever the model, and the significance

    at the 5% level is slightly different for two variables only (trees seen in the 140280 m range,

    proportion of bushes seen in the 70140 m range).

    A large number of inter-commune effects were tested with the random-effects model.They are significant in two cases only: transport networks seen less than 280 m away and

    trees seen less than 70 m away. As discussed in Sect. 3.3, the random-effects model presents

    drawbacks in comparison with the fixed-effects model estimated by the IV method. Thus,

    we comment below mainly on the results of the latter model.

    The parameters evaluated for non-landscape variables (property, transaction and location

    attributes) are consistent with other French studies (e.g. Cavailhs 2005). Interestingly, two

    land zoning variables are significant: house prices are lower for locations both in mixed

    residential and business zones (such mixed land use often entails nuisances for inhabitants),

    and on the periphery of the villages (i.e. zones UD of the zoning scheme): prices are lower

    on the periphery of towns or villages than close to the town hall.For landscape attributes, Table 2 shows that most objects located more than 70 m away

    have insignificant hedonic prices. Exceptions are farmland, where it is the view between 70

    and 280 m that matters and transport networks in sight, which are significant up to 280 m

    away. Water seen is also significant whatever the distance (with a surprising negative param-

    eter). The hedonic price of other types of land cover is insignificant beyond 70 m. Other

    variables were tested (dummies or quantitative variables for the rings beyond 280 m), which

    are all insignificant. It is as if households were short-sighted. This indifference to the view

    beyond a few tens of meters, or a few hundreds of meters, can be explained by the character-

    istics of the study zone, where distant horizons, when seen, are not formed by outstandingfeatures, sea, or snow-capped lines of mountains, etc.; on the contrary they are bluish-grayish

    in color, making them hard to distinguish against the skyline.

    10 In the first step (projection of the landscape variables on the instruments), the partial R2 is contained

    between 0.1 and 0.3, according to the model; the instruments are exogenous (Sargans statistic is superior

    to 0.20); finally Hausmans test rejects the endogeneity of the landscape variables (Students t values in the

    augmented equation are between 1.6 and +1.2).

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    582 J. Cavailhs et al.

    Table 2 Results

    (1) (2)

    Fixed-effects, 2SLS Random-effects

    INTERCEPT 11.89 12.50

    LSPACE 0.0126 0.0069

    LOT/LSPACE 0.0169 0.0167

    ROOMSIZE 0.0175 0.0012

    (ROOMSIZE)2 3.4E-5 7.0E-5

    STORIES 0.1349 0.0159

    BATHROOMS 18.508 2.639

    ATTIC 0.1108 0.0526

    BASEMENT 0.0428 0.0690

    PERIOD CONSTR.BEFORE 1850 0.0948 0.0832

    18501916 0.0580 0.0628

    19171949 0.05288 0.0875

    19501969 Reference Reference

    19701980 0.017 0.0523

    19811991 0.0546 0.0712

    19922002 0.0104 0.0565

    UNKNOWN 0.0229 0.0204

    LESS5 YEARS

    0.0451

    0.0613

    AN1995 0.2540 0.2694

    AN1996 0.1936 0.2158

    AN1997 0.2069 0.2305

    AN1998 0.1723 0.1956

    AN1999 0.1212 0.1326

    AN2000 0.0369 0.0410

    AN2001 0.0118 0.00639

    AN2002 Reference Reference

    SELLER OCC 0.0443

    0.0740

    BUYER OCC 0.1653 0.1688

    DIST BUYER 0.0064 0.00764

    FRENCH 0.0997 0.0366

    PRIVATE 0.0114 0.0088

    SALE OFFICE 0.0256 0.0353

    LAWYER OFFICE Reference Reference

    SUCC 0.0391 0.0589

    DIVISION 0.0583 0.0509

    NORMAL SALE Reference Reference100_200_ROAD 0.0735 0.0430

    POS-UD 0.0398 0.0230

    MIXED ZONE 0.0642 0.0331

    DIST TOWN HALL 4.0E-5 .0E-52

    SOUTH 0.00042 4.5E-5

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    GIS-Based Hedonic Pricing of Landscape 583

    Table 2 continued

    (1) (2)

    Fixed-effects, 2SLS Random-effects

    FLOODING 0.0208 0.0223

    STEEP 7.E-5 2.0E-5

    Ring Location from Dijon

    TREES SEEN

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    584 J. Cavailhs et al.

    4.3 Land Uses

    At the mean point of the residential lot, trees seen in the first 70 m have a significant positive

    hedonic price: the price of a house increases by 3% per additional standard deviation. More-

    over, the actual view of trees is valued more highly than their mere presence: the parameterof trees unseen is three times smaller. The latter is the value of nearby trees for recreational

    (walking areas), protective (against noise), and ecological (air quality, fauna and flora, etc.)

    functions, but not for scenery seen from home, which is higher by far.

    The difference between the two parameters may be attributed to the view sensu stricto,

    disregarding the other functions of tree-covered land uses. For a variation of one standard

    deviation of tree-covered area, the view represents therefore some 2% of the price of a house

    and the other functions (recreation, protection, ecology) about 1%. When the distinction is

    no longer made between seen and unseen tree-covered cells, as when the view from above is

    analyzed, a parameter of 0.0027 is obtained for a variation of one cell of those within 70 m,

    that is an intermediate value between cover actually seen in the ring (0.0057) and cover not

    seen (0.0017). The 3D geographic model therefore provides greater precision than the 2D

    model.

    The shape of areas covered by deciduous trees within a 70 m radius (landscape ecology

    indices were not calculated for conifers, which are rare) also exerts significant effects on

    house prices, compounding the foregoing: an additional patch has a positive contribution

    (+1.4% of the house price) and conversely 100 additional meters of boundary have a neg-

    ative effect (0.5%). The combination of these two variables provides an indication of the

    shapes valued: numerous patches with short edges correspond to rounded copses and not to

    massed forests or narrow, elongated formations.Surprisingly, the random effects model shows that trees seen less than 70 m away have a

    parameter higher on the periphery of the study area than close to Dijon. One might expect

    their price to be higher in this inner belt, due to their scarcity close to the city. Nevertheless,

    when trees are present but unseen their value is higher close to Dijon: wooded surround-

    ings are dearer close to the city than on the periphery of the zone, where the parameter is

    barely significant at the 10% level. Lastly, when seen more than 70 m away, trees command

    insignificant prices, confirming the myopia of households.

    Farmland seen at less than 70 m has an insignificant parameter, but crops and meadows

    seen between 70 and 280 m have a positive effect on house prices: +6.6% per standard devi-

    ation.11 It transpires from comparison with trees that the hedonic price of farmland seen ispositive at distances somewhat greater than for trees, although it remains confined to a radius

    of 300 m or so. This is consistent with other results (Johnston et al. 2002; Smith et al. 2002).

    Two contradictory effects may be combined in the 070 m range: the view of fields (positive

    effect) and nuisances (noise, smells, etc.), leading to an insignificant overall effect. Farmland

    that is present but not seen within the 70280 m radius commands a positive price, but only

    a fifth of that of farmland that is seen, confirming the importance of the view itself. The

    conclusions are similar, then, to those just presented for tree-covered cells.

    In view of these findings, it must be asked whether public support for farming and forestry

    is adequate in respect of one of its objectives which is to help maintain landscapes. For one

    thing, the hedonic price of farmland in view is far less than that of tree-covered land uses

    11 Farmland seen between 70 and 280 m makes up 56% of the area of the viewshed. Farmland is flat (it does

    not hide the view) and occupies extensive areas in the study region. It is to be expected then that abundant

    farmland is related to a wide viewshed and scarce farmland to a more restricted viewshed (because the land

    is then occupied by tall objects such as buildings or trees). The parameter estimated for the 70280 m ring

    therefore corresponds to a wide viewshed largely occupied by farmland.

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    GIS-Based Hedonic Pricing of Landscape 585

    in view, whereas public support is in inverse proportions; for another thing, such support is

    unrelated to the location of farmland relative to housing while households place a positive

    value on farmland only when it is very close to housing.

    The interaction parameters between lot size and the area of both farmland seen and trees

    seen are negative: the larger the lot, the lower the marginal price of visible farmland or trees.There may be a substitution relationship between green landscape and lot size.

    In contrast to tree-covered and farmland cells just examined, roads (and railroad tracks) in

    view at less than 280 m lower the price of a house by 1.3% per standard deviation. Networks

    within this radius but not in view command an insignificant price: it is less the presence

    of roads that is a nuisance when they are not seen (although they are source of danger, air

    pollution, and noise) than the actual sight of them, as they are a visual obstruction. This

    result is consistent with that for trees and agriculture: the presence of an object counts less

    than whether or not it can be seen. Beyond the first 280 m, the sight of roads no longer

    significantly affects house prices, indicating that such nuisances remain confined to a narrow

    strip.12 Transport networks seen in the 280 m circle have a clearly more negative parameter

    close to Dijon, where these networks are dense and crowded, than at the periphery of the

    region, where unseen roads in this circle have a positive sign (probably because they are

    correlated with omitted variables: local public goods, etc.).

    Among other types of objects, buildings are the most common land cover close to housing.

    Their hedonic price is insignificant whatever the distance. Two opposite effects might explain

    this finding: on the one hand, nearby houses allow social relations with neighbors, and on

    the other hand the view of these structures may be less appreciated than green land cover.

    The parameter of bushes seen is insignificant (except in the 70280 m range, with a positive

    sign), which may be explained by the heterogeneity of this type of object (coppices, fallowland, groves, recent plantations, etc.). Finally, the sight of rivers or lakes has a significant

    negative sign, which is not due to flooding risk (zones liable to flooding are controlled in the

    equation). This result is contrary to the usual findings of the literature; however it is based on

    a small number of observations (only 69 houses have viewsheds with 5% or more of water

    in the 0280 m ring).

    Lastly, landscape composition variables were introduced into the regression by a step-

    wise method, and four indices were kept: the number of patches of deciduous trees and their

    lengths within a 70 m radius (as said), a compactness index ranging from 0 (compact forms)

    to 1 (elongate forms), and the number of patches of farmland located in the 70280 m range.

    For 1% of additional elongation, price rises by 0.23%, and by 0.2% per additional patch offarmland. The results, for the combination used here as for other indicators taken separately,

    show that division, complexity, non-contiguity, landscape fragmentation, mosaic patterns,

    etc., command positive hedonic prices.

    Note that over several decades, the re-parceling of farmland has formed large plots with

    simple geometric shapes to facilitate work with farm machinery, hedges have been torn up

    and tracks plowed up to enlarge production areas while crop rotations have been simplified.

    Forests have undergone comparable, although less extensive, change with the same objec-

    tive of increasing productivity. There is a clear contrast between landscapes arising from

    the productive function of farming (and forestry) and landscapes valued for the non-marketfunctions of these activities.

    12 Note that a location at less than 200 m from a freeway or a major road reduces the price by 7.8% (see the

    100_200_ROAD parameter in Table 2).

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    586 J. Cavailhs et al.

    5 Discussion and Conclusion

    Hedonic price models have been combined here with a GIS-based geographic model to eval-

    uate the price of landscapes seen from houses in the urban fringe of Dijon (France). The

    geographic model is used to identify, with a resolution of 7 m, 12 types of objects fromsatellite images and to measure the viewshed, by trigonometry, taking into account relief and

    obstacles that may block the view. The landscape is quantified in terms of viewshed and of

    the type of objects seen and unseen. The econometric models are the first stage of Rosens

    approach, estimated from 2,667 house sales, which allows for endogeneity by the instru-

    mental method and spatial correlations by either a fixed-effects model or a random-effects

    model.

    The main advantage of our geographic model is that it can be used to calculate landscape

    variables from any of the 144 million cells of the study region. Estimations can thus be

    extended to new transactions if the economic data base is broadened. Results can be mapped

    too, as the following example shows. The price of a marginal loss of viewshed due, say, to

    new building blocking out 10% of the view can be calculated at any point. Hedonic prices are

    used to calculate the predicted price of this marginal loss of landscape, which is equal to the

    sum of the quantity of each hidden object weighted by its price. Figure 4 shows the result for

    one town, Genlis, and the surrounding villages. Obstruction of 10% of the viewshed entails

    a loss of value on the outskirts of villages, where the view is primarily of fields and trees:

    sometimese2000 or more (1.52% of the house price). It has a positive price where the new

    buildings mask roads.

    This example shows that the pairing of the geographic model (allowing the landscape

    to be measured from any point) and the econometric model (allowing hedonic landscapeprices to be predicted for marginal variations in its attributes) opens up new perspectives.

    Given the current state of research it is not yet possible to use such models for prescriptive

    purposes, say for selecting the location of a new building by reducing its monetary impact

    on the value of the view for its neighbors. But this might be a possible future use. The geo-

    graphical model presented here has been used by Electricit de France (EDF), the French

    public-sector power company, to route its high-voltage power lines where they are least

    visible.

    The main shortcoming of this geographic model is that it yields results which are approxi-

    mation of the actual situations and which may be biased if certain assumptions are inaccurate.

    In particular, a comparison with orthophotographs shows that the present model may under-estimate the viewshed by exaggerating the amount blocked out by buildings.

    The great advantage of the fixed-effects econometric model is that it takes into account all

    the factors depending on distance from Dijon. Almost all the covariates, including those for

    landscapes, vary with this urbanrural gradient and the co-variations are almost impossible to

    account for without the fixed-effects model. The main drawback of this model is that it allows

    for intra-communal variations of landscape variables only, and ignores inter-communal vari-

    ations. Moreover, whatever the precautions taken to avoid the effects of omitted variables,

    the method cannot guarantee freedom from bias related to this problem. The method also

    allows us to test for endogeneity of explanatory variables (including landscape attributes) byusing the instrumental method.

    The results are consistent with the literature on several points. They show, first, that it is

    above all the view of the tens of meters around a house that counts; beyond a hundred meters

    or so, a few attributes remain significant up to 150300 m, but no farther. Second, the results

    confirm that land cover around houses has a significant effect on housing prices, generally

    with the expected signs: trees have positive hedonic prices, as does farmland, while roads

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    GIS-Based Hedonic Pricing of Landscape 587

    Fig. 4 The price of an obstruction of 10% of the view in and around Genlis. Note: For cells located morethan 200 m for built polygons, the price of obstructed view is not calculated as it would be absurd to calculate

    the price of loss of view from a house located in the middle of a field or a forest. These cells are light grey in

    the Figure (not calculated box). For a cell belonging to or close to a built polygon, the blocking of the view

    generally entails a loss of value, which loss is greater when the cell is located on the edge of the village (everdarker greys). In some instances (in white in the Figure), the blocking of the view is reflected by an increased

    value when it is roads that are masked by new buildings.

    have negative hedonic prices. In some instances the signs are counterintuitive (water), which

    is not uncommon in the literature and shows that further research is required.

    We also show, which is new in the literature, that it is the view that influences the real-

    estate price and not the mere land cover: trees or farmland close to a house but not visible

    from it command far lower hedonic prices than when they are seen. Trees close to houses

    but out of sight contribute to the residential setting by providing amenities (peace and quiet,fresh air, etc.) but their hedonic price is a third of that of trees in view. Unseen farmland is

    worth just one-fifth of the hedonic price of farmland in sight and unseen nearby roads have an

    insignificant hedonic price, while they are a source of nuisances (noise, danger, etc.). These

    results about the importance of the actual view are confirmed by the results about landscape

    shapes: landscape shape indexes show that households prefer complex, fragmented shapes

    and mosaic patterns of scenery.

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    588 J. Cavailhs et al.

    However, our method is reductive because it simplifies in the extreme what a landscape

    is and evaluates only use values related to residential consumption. Moreover, the hedonic

    method used does not ensure full compliance with the all-else-being-equal requirement. The

    point that in spite of these limitations on the whole it yields significant results is encouraging.

    However, we are aware that other methods are also required to enhance knowledge in thedomain of the economic valuation of landscapes.

    Appendix: Descriptive Statistics (Landscape Variables)

    See Table 3

    Table 3

    Variable Ring Number of

    houses with

    the attribute

    Value for houses with the attribute

    Mean Total SD Intra-SD Inter-SD

    Trees seen

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    GIS-Based Hedonic Pricing of Landscape 589

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