There are actually four types of government land prices. The surveys are based on assessments by real estate appraisers, who, taking into account profitability and transactions in neighboring areas, determine values for 1 sq. meter plots. The assessments assume that the land is utilized as efficiently as possible. There are also two other types of official land prices, used for tax and valuation purposes, as well as the actual asking and transaction prices. Here is a quick rundown:
- The kouji-chika (appraised land value) is published annually by the Ministry of Land, Infrastructure and Transportation on April 1, gives prices for around 30,000 points nationwide, focusing on urban areas. There is a map available with these values here.
- The kijun-chika (average residential and commercial land price) is published annually by each prefecture on July 1 for around 25,000 points nationwide, based on local land appraisers’ reports. This measure also covers non-urban areas such as forest and agricultural land. Map
- The rosenka (prices of land fronting major roads) is published by the National Tax Administration Agency and is comprised of two different measures: the koteishisanzei (fixed asset tax) rosenka and the souzokuzei (inheritance tax) rosenka. The souzokuzei rosenka is the most widely used value for roughly estimating land values in relative locations. The rosenka is published each October.
- The koteishisanzei-hyokagaku (assessed value of fixed assets) is computed by the Home Affairs Ministry every three years for all taxable properties, and forms the basis for property tax (Fixed Asset Tax and Urban Planning Tax) calculations. The value is not commonly disclosed except to the taxpayer in question.
- The actual transaction price of real estate, or jisei-kakaku. This is the market price, and can be vastly different from the official prices of land. These prices are not published and are only made available to appraisers on individual basis by means of voluntary inquiry forms sent to the transaction participants.
- The advertised prices of properties for sale. Properties for sale are published by many websites including AtHome and Yahoo Real Estate. Akasaka Real Estate keeps an archive of these listings in Tokyo since 2006 and has made these available in English translation here. The difference between the transaction price and the lowest advertised price for a property is relatively constant at about 5%. As a result the best way to value an apartment in Tokyo is to use these advertised prices.
The kijun chika and kouji chika are commonly used by economists to determine trends in land values, while real estate practitioners use rosenka more often. Japanese appraisers use all the above indicators in their reports. Unfortunately none of these valuations are particularly useful to calculate the actual market value of a property. Professor Nishimura's academic paper Distortion in Land Price Information describes these serious problems in the governmental information system. Due to a lack of reliable government statistics and transaction data the best way to value property in Tokyo is using #6 "The advertised prices of properties for sale".