Yoji Kunimitsu

Is long-term climate change beneficial or harmful for rice total factor productivity in Japan: evidence from a panel data analysis

Under global warming, influences of heat stress and flooding on rice production are becoming critical in Japan, but it is still under discussion whether future climate change is beneficial or harmful for Japanese rice production. This study aims to evaluate the impacts of long-term climate change on rice total factor productivity (TFP) by a panel data analysis. We estimate a regression model to link rice TFP to climate factors via yield, quality, and flood influence by using crop models, and then project future TFP levels from the results of the high-resolution model for interdisciplinary research on climate (MIROC). The results demonstrate that climate change has a positive effect in the northern regions, such as Hokkaido and Tohoku, but it decreases rice TFP in other regions, especially in the western regions, after the 2050s. Furthermore, climate change increases fluctuations in rice TFP of the western regions. To overcome negative impacts, a forward shift in the rice transplanting time is effective. Second, the potential impacts of climate factors, shown by the elasticity values of rice TFP, are 0.18 (via yield), 0.09 (via quality), and −0.03 (via flood influence), but these climate impacts are weaker than socio-economic factors, such as economies of scale and research and development capital stocks. Third, regional gaps in rice TFP are enlarged over time because of different impacts of climate factors as well as socio-economic factors. Such fact-findings can be used to reconsider agricultural policy.

Potential conflicts for the reuse of rice husk in Thailand

This study aims to investigate the impact of rice-husk power generation on agricultural uses of rice husk and its ash. We conducted case studies at a rice-husk power plant and organic farming groups in northeast Thailand. The case study on a rice-husk power plant showed that rice husk was useful in generating electricity without consuming fossil fuel, while husk ash, the by-product, could be utilized as silicate supplement for farmland soils. The case study on organic farming groups indicated that rice husk was one of the indispensable materials in conducting organic farming with locally available resources. On the basis of these findings, an analytical study on possible husk uses in Thailand was conducted, in which three potential major uses of rice husk were considered: i.e. (1) fuel use inside rice mills followed by husk-ash reuse, (2) fuel use at power plants followed by husk-ash reuse, and (3) direct reuse of husk for compost production. The result indicated that there would be conflicting demands for rice husk among those uses in the future. Therefore, there needs to be a strategy for balancing husk uses among them.

A benefit incidence analysis on the far-reaching effects of paddy-field consolidation projects

A paddy-field consolidation (PC) project was carried out with large subsidies as a public investment by prefectural governments in order to improve agricultural productivity in Japan. The purpose of this study is to analyze the quantitative benefits and costs of the PC projects. A benefit incidence (BI) analysis was used in view of the far-reaching effects on farmers to consumers. The results were as follows. First, with the recent decline in rice price, certain farmer benefits primarily derived from the projects have been transferred to consumers through rice price. The transfer ratio was more than half of the total improvement effect of rice productivity which occurred on the farmers’ side, and all economic sectors including farmers and consumers received net benefit even though all sectors paid construction costs or taxes. Therefore, maintaining flexibility in rice price plays an important role to secure net benefits and obtain an agreement of all people involved in the project. Second, some benefits with regard to effects on the rural environment that was not expected at the time of planning were revealed on many project sites. Evaluating these intangible effects will be more important for the tax payers in order to evaluate how the environment friendly planning of the project achieved benefits.

Technological spillover in Japanese rice productivity under long- term climate change: evidence from the spatial econometric model

Rice productivity will be affected by climate conditions not only in own region but also in neighboring regions through technological spillover. Measuring such direct and indirect influence of future climate change is important for policy making. This study analyzes socio-economic and climate factors in rice total factor productivity (TFP) and evaluates technological spillover effects by using the spatial econometric model. To consider geographical situation, we use hydrological model in addition to crop-yield and crop-quality models. Results show that spatial autoregressive tendencies were observed in rice TFP, even though the influences of climate factors were removed. Such spatial dependence brings about synergistic effects among neighboring prefectures in northern Japan and depression effects, like a spatial trap, from neighbors in southern Japan. Substantial impacts of climate change were as high as socio-economic factors but different in degrees by regions. Also, future climate change estimated by the global climate model enlarged fluctuation degree in rice TFP because accumulative or cancel out effects of temperature and precipitation occurred year by year. Therefore, technological development in rice production and provision of precise climate prediction to farmers are important in order to ease and mitigate these influences.

Measuring the implicit value of paddy irrigation water: application of RPML model to the contingent choice experiment data in Japan

For efficient use of water as a limited resource, evaluation on the water value is critical, but there is little information in Asian paddy irrigation. This paper proposes the method for measuring implicit price of paddy irrigation water by using the choice experiment (CE) data with contingent scenarios. Empirical results demonstrated that (a) the estimated implicit price of water showed reasonable value as compared to the production indexes, (b) the random parameter multinomial logit model was more suitable than the conventional multinomial logit model to treat the CE data, and (c) the implicit price is much lower than the full cost price, indicating that full cost pricing probably damages and ruins rice production too seriously in Japan. As seen above, the method proposed here is useful for decision making on water pricing policies and easy to apply to different irrigation systems under limited data of water value.

Economic Ripple Effects of a Biogas Electricity Power Plant as Part of Earthquake Disaster Restoration in the Coastal Area of Iwate Prefecture

The coastal area of Iwate Prefecture was seriously damaged by the Great East Japan Earthquake in 2011, and the revitalization of this region is an important issue in Japan. This chapter aims to estimate the input–output tables of this region before and after the earthquake and to use these tables to show the impacts of the earthquake and the impacts of a particular revitalization measure: the construction of a biogas electricity power plant. The results showed several distinct features. First, value-added production in 2011 was higher than the previous year because of recovery investment, but both intermediate inputs and the total production decreased. This occurred because the ratio of value-added production in the construction sector was higher than in other industries that were seriously damaged by the earthquake. Second, investment demand increased in 2011 and 2012, but the intermediate inputs and private and public consumption decreased because of the earthquake. The power-of-dispersion coefficients and production-inducement coefficients were slightly changed by the earthquake, but the increasing rate of induced production was low after the earthquake. Third, the multiplier value of induced production for the construction of a biogas electricity power plant would have been 0.64, if it had been constructed before the earthquake. However, that value after the earthquake was 0.17 because industrial linkage was damaged. Compared to the conventional electricity sector, the biogas electricity generation sector induced more production because the import rate of this sector was zero and most induced demand occurred within the region. Therefore, a biogas electricity power plant can contribute to the revitalization of a regional economy although the electricity generation capacity is small.