The latest data on land prices paint an overall positive picture. Prices in both commercial and residential areas in the three largest metropolitan areas — those around Tokyo, Nagoya and Osaka — have continued to rise, while the margin of year-on-year decline in other parts of the country have declined, with prices in the big cities that constitute the core of regional economies, such as Sapporo, Sendai, Hiroshima and Fukuoka, moving up.

What the data also show, however, is the growing polarization in the regions outside the big metropolitan areas — between those core regional cities and many others that continue to suffer from population drain and falling land prices. The gap continues to reflect the uneven results of the Abe administration's economic policies that appear to have reversed the asset deflation mainly in large urban areas. Prime Minister Shinzo Abe needs to do more in his avowed efforts to spread the benefits of "Abenomics" across the country through regional revitalization.

According to the recent data from the land ministry, the average commercial land price in the Tokyo, Nagoya and Osaka metropolitan areas as of July 1 was 2.3 percent higher than a year earlier. The average price of commercial land in Sapporo, Sendai, Hiroshima and Fukuoka rose faster at 3.8 percent, but the average price in the rest of the country continued to fall.

In addition to the moderate upward trend in the economy, the Bank of Japan's ultra-easy monetary policy, the surge in share prices and tax credits on housing loans are believed to have contributed to the real estate investment boom in urban areas, along with the record number of inbound tourists that pushed up hotel occupancy rates. Robust appetite by wealthy consumers and foreign investors have pushed up sales of high-priced condominiums in central Tokyo, while construction of large office complexes proceed under urban redevelopment projects.

Concerns are even surfacing over the possibility of real estate bubbles and speculative trading. Prices of commercial land near JR Kyushu's Hakata Station in Fukuoka, where a redevelopment project is under way, surged 19 percent. Commercial land prices outside the east exit of Nagoya Station shot up by 45.7 percent in just a year — partly fueled by hopes for further rises in the future when the maglev train service linking Tokyo and Nagoya opens by 2027. Close tabs need to be kept over possible signs of overheating from speculative real estate transactions.

Nationwide, the average price of commercial land fell 0.5 percent for the eighth consecutive year-on-year fall, and residential land declined 1 percent for the 24th annual decrease in a row — though the margin of decline has shrunk in recent years. A closer look shows the widening gap between the core regional cities whose land prices are going up for their convenience on one hand, and those that remain left out of the loop of the Abenomics boom on the other.

Outside the three biggest metropolitan areas and the core regional urban centers, cities with a population of 100,000 or more that have seen their residential land prices rise include Fukushima, where demand is up for resettlement of residents displaced by the radiation fallout from the March 2011 nuclear disaster at Tokyo Electric Power Co.'s Fukushima No. 1 plant; Kanazawa, Ishikawa Prefecture, where the recent opening of the Hokuriku Shinkansen Line has boosted tourism demand; and Naha, Okinawa Prefecture, which has been attracting increased numbers of visitors and settlers.

A pickup in the average land prices in regions outside of the Tokyo, Nagoya and Osaka areas, however, is not predicted since Japan's population decline and the aging of society are forecast to accelerate and as the exodus of younger-generation workers to Tokyo continues. In Akita Prefecture, where the population is decreasing roughly 10,000 a year, both the commercial and residential land prices fell the steepest among the 47 prefectures at 4.6 percent and 4.0 percent, respectively. While land prices went up for 72 percent of the sites surveyed in Sapporo, Sendai, Hiroshima and Fukuoka, the prices fell in 75 percent of all the sites covered in the regions outside the big metropolitan areas. The trend of polarization in land prices among the regional economies is likely to continue.

The trend underlines that Abe's campaign pledge to "deliver the benefits of Abenomics all through the country" is nowhere near finished. As a major part of its regional revitalization bid, the administration plans to introduce a new type of central government grant for prefectures and municipalities beginning in fiscal 2016 to support their efforts to facilitate resettlement of people from urban areas and promote local tourism. Though of course the size of such grants alone won't determine the effectiveness of such a policy, the amount for such spending in the ministerial budgetary requests for the next fiscal year was around ¥100 billion — even smaller than the ¥170 billion earmarked for the pilot programs in the supplementary budget for fiscal 2014, triggering doubts in some quarters as to how serious the national government is on this issue. It appears again that the administration isn't doing enough to close the regional gap in the Japanese economy.