The Price of Biodiversity

This page shows part of my research at Aarhus University. The research uses home sales to estimate what the ecological quality of nearby nature is worth to Danish homebuyers, as reflected in the prices they pay. I have found no earlier estimate of the price of ecological quality in Danish or Scandinavian property markets.

Work in progress. This page summarises preliminary findings from an unpublished working paper. The estimates are associations that should not be read as causal effects and may change before the paper is released. The map shows ecological-quality scores and does not show property valuations. Last updated September 2026.

An implicit price of zero

When a road or a building is appraised, its costs and benefits are weighed in money. Biodiversity usually enters that calculation at zero, because no measurement of it reaches the appraisal.

Denmark has a national map of ecological quality, the Biodiversitetskort, that scores each part of the country for its potential to support wild species. My research asks whether Danish homebuyers pay more to live near higher-quality nature and, if they do, how much more.

Ecological quality across Denmark

Average score within one kilometre of the homes sold in each parish, across about 964,000 recorded home sales, 2015 to 2025. Pick an index below. Darker always means richer nature.

Find a parish

Index:

Bioscore (1 km mean)

Static map of Denmark shaded by average ecological-quality bioscore per parish. Coastal areas, north Zealand and the central Jutland lakes show the highest ecological quality. Dense cities and intensively farmed areas show the lowest.

The interactive version of this map needs JavaScript. The figure above shows the same data: the average ecological quality within one kilometre of homes in each Danish parish.

How to read this. The colour shows the Biodiversitetskort score, a measure of habitat quality and the presence of species of conservation concern, averaged over the homes sold in each parish. A higher score means richer potential for wildlife. The colours sort parishes into six groups by rank, from very low up to the top few percent. They show how each parish compares with the rest of Denmark rather than against a fixed standard. A parish in the top group is among the richest in the country, which is not the same as a perfect score. This is not a property valuation, and it does not tell you what nature is worth for any individual home. Parishes with fewer than 30 sales are left grey because their average is too noisy to show.

What the three indices mean. The Biodiversitetskort score is the sum of two parts, a species score and a landscape score. The toggle above maps each on its own.

0 to 19 · species + landscape

Composite (bioscore)

The full Biodiversitetskort score, species records and landscape quality together. This is the measure behind the price estimate.

0 to 9

Species (artsscore)

Threat-weighted records of red-listed wildlife actually observed nearby. It leaves out the coast and the other landscape proxies.

0 to 10

Landscape (proxyscore)

Habitat, wetlands, hedgerows, old forest, low nitrogen and coastal proximity, the conditions that predict where wild species are likely to live.

What the split shows. The price premium comes out about the same whether it is measured on the full score or on the species part alone. On its own that near-match is expected, since the species part makes up most of the full score. A stronger test, described with the distance chart further down, enters the two parts in the same regression, so that each is estimated with the other held fixed. When ecological quality is measured within 500 metres of the home, the species part accounts for the premium. Within 1 kilometre the two parts are too closely correlated for the test to separate them.

View the data as a table

Find your parish

Pick a parish to see where it sits in the national ranking, using the composite score for ecological quality and satellite NDVI for greenness.

The parish profile needs JavaScript. The table under the map lists the scores for each parish.

What homebuyers reveal

Three findings from the analysis, stated in round numbers because the work is still preliminary.

~2.8%

Nature has a price

On average, homes surrounded by higher-quality nature sell for more. The bioscore, from the national Biodiversitetskort map, is an index of ecological quality scored 0 to 19 and averaged here within 1 kilometre of each home. When homes of the same type within the same parish are compared, one additional bioscore point is associated with about 2.8 percent higher prices. At the median sale price of DKK 2 million that corresponds to about DKK 57,500. The 95 percent confidence interval, the range of values compatible with the data at the conventional standard of statistical evidence, is DKK 40,000 to 75,000. Homes of the same type in the same parish typically differ by about half a point. One standard deviation of that within-parish variation, 0.56 points, is associated with about 1.6 percent higher prices, or DKK 32,000, with a 95 percent confidence interval of DKK 23,000 to 42,000.

~70%

Mostly about who lives where

Without adjusting for any other characteristic of the home or its location, one bioscore point is associated with about 10 percent higher prices across the country, roughly three and a half times the within-parish figure of 2.8 percent. Around seventy percent of that raw association reflects other differences between homes near high-quality nature and the rest, mainly the parishes they are in. I read most of that as spatial sorting, with buyers who value nature settling in parishes with high ecological quality. The premium that remains within a parish is smaller but still present.

< 1 km

A local effect

The premium is of similar size whether nature is measured within 100 metres or within 1 kilometre of the home. At 5 kilometres it is not distinguishable from zero. I read this as the profile of an amenity that residents use close to home, on walks nearby and through what they see and hear from home.

How far the premium reaches

The cards above give rounded summaries. This chart shows the estimates on which the card headed “A local effect” is based. Each line shows the price premium for a one-standard-deviation increase in ecological quality, with ecological quality measured over circles of increasing radius around the home, from 100 metres to 5 kilometres. A standard deviation here is the typical spread of each score across all homes in the sample. For the composite score that spread is 0.97 points, close to one full point. The composite figure at 1 kilometre in this chart, about 2.8 percent, is therefore almost the same as the per-point figure in the first card. The 1.6 percent figure in that card refers to a smaller step, one standard deviation of the variation between homes of the same type in the same parish, which is 0.56 points. Within 1 kilometre of the home the composite premium is about 2 to 3 percent per standard deviation for each circle. The shaded band around each line is its 95 percent confidence interval. Because the bands for the circles within 1 kilometre overlap, the data do not show where within that kilometre the premium is largest. The estimate for the 2 kilometre circle is lower. At 5 kilometres the premium is not distinguishable from zero. The species line lies close to the composite line. That closeness is largely mechanical, because the species score accounts for just over half of the variation in the composite and the two are closely correlated. A more demanding test enters the species score and the landscape score in the same regression, so that each is estimated with the other held fixed. In that test both scores show a premium at 100 metres. At 500 metres the species score accounts for the premium, while the landscape score, which contains the coast, is not distinguishable from zero. At 1 kilometre the two scores are too closely correlated for the test to separate them. When all homes within a kilometre of the coast are dropped, the estimated premium is, if anything, larger. Nearness to the sea therefore does not explain the premium in these tests, although I cannot exclude some remaining coastal influence.

Show:

With ecological quality measured over six circles from 100 metres to 5 kilometres, the premium per standard deviation of the composite score is about 2 to 3 percent for each circle within 1 kilometre, where the confidence intervals overlap. It is not distinguishable from zero at 5 kilometres. At 1 kilometre it is about +2.8 percent for the composite score, +2.8 percent for the species score and +2.3 percent for the landscape score.

Each score is measured against its own spread, so the three lines can be compared directly.

Turn a line off to compare, or hover a distance to read the exact premium and its 95 percent range.

These are associations, measured after comparing homes of the same type in the same parish, with nationwide price trends removed quarter by quarter. They are reported as estimated, not as causal effects, and with no claim of a bound in either direction.

How it is measured

The estimate comes from a hedonic price model. It is fitted to about 850,000 geocoded home sales, the subset of the roughly 964,000 recorded sales shown on the map with complete information on each home characteristic and control the model requires, with controls for the size, age, and construction of each home, its energy rating, distance to the coast and to transport, noise exposure, and the general greenness of the surroundings. Comparing homes of the same type within the same parish, with nationwide price trends removed quarter by quarter, separates the role of ecological quality from the many other things that drive prices.

Greenness is not the same as biodiversity. A mown lawn and a species-rich meadow can look equally green from a satellite. The model holds greenness constant, so the estimate reflects ecological quality rather than just the amount of vegetation.

Across the roughly 964,000 home sales the two barely track each other, with satellite greenness and the composite ecological-quality score correlating at about r = 0.10, and they pull apart most in intensively farmed areas, where a bright green field can score low.

Map of Denmark shaded by satellite greenness. Farmland across Jutland and Funen shows as deep green, while coasts, dunes, heaths and city centres are paler. — The two maps shade the same country by greenness and by ecological quality. Much of the farmland across Jutland and Funen looks green from a satellite but scores low for wildlife, so parishes like Lysabild and Skamby rank near the top for greenness and near the bottom for ecological quality. Places built on dunes, heath and coast, like Skagen and Rømø, run the other way.

The same map of Denmark shaded by the composite ecological-quality bioscore. The farmland belt that looked green now scores low, while coasts, dunes and the central-Jutland lake district score high. — The two maps shade the same country by greenness and by ecological quality. Much of the farmland across Jutland and Funen looks green from a satellite but scores low for wildlife, so parishes like Lysabild and Skamby rank near the top for greenness and near the bottom for ecological quality. Places built on dunes, heath and coast, like Skagen and Rømø, run the other way.

See how greenness and biodiversity diverge

What this is, and what it is not

What it is

An estimate of the value of ecological quality in the Danish property market, based on what homebuyers pay. I have found no earlier estimate of this value in Danish or Scandinavian property markets.
A market-based price for the part of nature’s value that is reflected in house prices, for use in Danish cost-benefit analysis, where biodiversity usually enters at zero.
A full account, including how much of the raw premium is explained by who lives where.

What it is not

A property valuation, or a price for the nature near any single home.
A causal claim. These are associations, with the limits any observational study carries.
A finished result. The paper is unpublished and the numbers may change before release.

Explore it yourself

Four interactive tools in the Lab, built on this same research. Each link opens the Lab at that tool.

Nature Next Door

Move a slider along the local bioscore and read the price change linked to richer nearby nature, with its range.

Open in the Lab →

The Sorting Machine

Play with spatial sorting, the tendency of buyers who value nature to settle near it, and watch the raw premium shrink to the within-parish figure of about 2.8 percent per bioscore point.

Open in the Lab →

Is greener always richer?

Compare satellite greenness with measured ecological quality across the country, point by point.

Open in the Lab →

Biodiversity in the business case

See how putting a price on nature changes a cost-benefit calculation for a project.

Open in the Lab →

Where this fits

This is part of my research at Aarhus University on measurement, uncertainty, and decision-making in infrastructure and environmental policy. The aim is to give cost-benefit analysis a defensible price for biodiversity, so that the value of nature is counted rather than assumed away.

A short summary of the working paper sits with my other research. A link to the full paper will be added when it is released.

See the research summary About my research

Data sources

Ecological quality: Biodiversitetskort (bioscore, 2021 edition), Danish Centre for Environment and Energy (DCE), Aarhus University.
Parish boundaries: DAGI, Styrelsen for Dataforsyning og Infrastruktur (SDFI) via Dataforsyningen, licensed CC BY 4.0.
Property transactions: Boliga.dk, 2015 to 2025.
Building characteristics: the national building register (BBR), via Datafordeler.
Energy labels: EMOData, Danish Energy Agency (Energistyrelsen).
Noise: strategic noise maps for 2017 and 2022, Danish Environmental Protection Agency (Miljøstyrelsen).
Train stations: © OpenStreetMap contributors, available under the Open Database License.
Greenness: Normalized Difference Vegetation Index from a Sentinel-2 summer 2021 composite.

Referring to this work: the working paper is titled “The Price of Biodiversity: Hedonic Evidence from Danish Housing Markets” and is not yet published. For press questions, use the contact page.

Interested in this work?

I am always glad to discuss biodiversity valuation, environmental cost-benefit analysis, and the economics of nature.

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