Masaji Sakagami

Weighting across safeguard subjects for LCIA through the application of conjoint analysis

BackgroundMany types of weighting methods, which have integrated the various environmental impacts that are used for life-cycle impact assessment (LCIA), were proposed with the aim of developing the methodology as a useful information resource for decision making, such as in the selection of products. Economic valuation indexes, in particular, have attracted attention, as their assessment results are easy to understand and can be applied in conjunction with other assessment tools, including life-cycle costing (LCC) and environmental accounting. Conjoint analysis has been widely used in market research, and has recently been applied to research in environmental economics. The method enables us to provide two types of assessment results; an economic valuation and a dimensionless index. This method is therefore expected to contribute greatly to increasing the level of research into weighting methodology, in which an international consensus has yet to be established. Conjoint analysis, however, has not previously been applied to LCIA.ObjectiveLCA National Project (METI/NEDO/JEMAI) has conducted a study aimed at the development of a Japanese version of the damage-oriented impact assessment method called LIME (Life-cycle Impact assessment Method based on Endpoint modeling), in order to enhance its reliability and transparency. This study aimed at the application of conjoint analysis to the step of weighting in LIME. An ultimate goal of the research is to determine an amount of willingness to pay (WTP) for avoiding a unit quantity of damage of every safeguard subject (endpoint).MethodsPotential annual damages of four safeguard subjects (human health, biodiversity, social assets, and primary production), known as normalization values in LCIA, were used as fundamental information in this study. These data can be obtained through damage assessment. Taking this background into account, we performed a comparison of importance among the four safeguard subjects defined in LIME by applying conjoint analysis. A choice-based type of questionnaire was prepared for the interview with the respondents selected by random sampling. Pre-tests were conducted for 108 respondents in advance of the main survey. After we confirmed that the analyzed results of the pre-test were revealed to be statistically significant, the main surveys were conducted for 400 respondents by interviewing. WTP per quota can be determined by statistical simulation based on the random utility theory reflecting the responses to the questionnaires by random sampling.Results and DiscussionThe values of one unit (standard) of attributes were significant statistically at the 1% level (all of the p value for coefficients of safeguard subjects were less than 0.0001). Based on the calculated results, two types of weighting factors, an economic valuation and a dimensionless index were obtained. The capability of generating two kinds of weighting factors is unique to conjoint analysis. A relative comparison of importance among the four categories indicates that human health gains the highest recognition, biodiversity gains the second highest recognition, and the weight of primary production and social assets have been estimated to be relatively smaller than the other two safeguard subjects.ConclusionIt is desirable to prepare a small number of attributes when conducting a conjoint analysis, because the efforts of respondents have to be reduced as far as possible. We confirmed that the damage-oriented method, which minimizes the number of attributes, is suitable to the requirement of conjoint analysis, because the results of comparisons among safeguard subjects were statistically significant, and showed that the contents of the questionnaires were well understood among the respondents. Judging from the results of this study, where statistical significance has not even been fully verified in the conventional research on the development of weighting coefficients for LCIA, it can be concluded that the weighting factors derived from this study based on the economic theory have a possibility to reveal the impact of environment on society.

Statistical analysis for the development of national average weighting factors—visualization of the variability between each individual’s environmental thoughts

PurposeWeighting is one of the steps involved in life cycle impact assessment (LCIA). This enables us to integrate various environmental impacts and facilitates the interpretation of environmental information. Many different weighting methodologies have already been proposed, and the results of many case studies with a single index have been published. However, a number of problems still remain. Weighting factors should be based on the preferences of society as a whole so that the life cycle assessment (LCA) practitioner can successfully apply them to every product and service. However, most existing studies do not really measure national averages but only the average of the responses obtained from the people actually sampled. Measuring the degree of uncertainty in LCIA factors is, therefore, one of the most important issues in current LCIA research, and some advanced LCIA methods have tried to deal with the problem of uncertainty. However, few weighting methods take into account the variability between each individual’s environmental thoughts. LIME2, the updated version of life cycle impact assessment method based on endpoint modeling (LIME), has been developed as part of the second LCA national project of Japan. One of the aims of LIME2 is to develop new weighting factors which fulfill the following requirements: (1) to accurately represent the environmental attitudes of the Japanese public, (2) to measure the variability between each individual’s environmental thoughts and reflect them in the choice of suitable weighting factors.MethodsThis study adopted the technique of conjoint analysis, which is currently the most advanced methodology available in the field of environmental economics. Using a random sampling process, 1,000 individual responses were collected. Every response was based on an interview survey designed to minimize bias. We used a random parameter logit model to estimate the preferences of society. Statistical values based on this model can be considered to reflect the variability between each individual’s environmental thoughts. The calculated results can then be used to develop integration factors in LIME2, enabling us to express LCIA results as a single index, such as external cost.Results and discussionThe calculated values were significant statistically at the 1% level (all p values for the safeguard subject coefficients were less than 0.0001), with the exception of “social assets.” Based on the calculated results, two types of weighting factor, an economic valuation and a dimensionless index, were obtained. A relative comparison of importance among these four categories indicates that “biodiversity” receives the highest level of recognition, followed by “human health” and “primary production,” while the weight of “social assets” rate lower than the other safeguard subjects, in comparison. Using the calculated results produced by the RPL model, the probability density of the variables for individual preferences could then be derived and displayed. The coefficients of variance for the estimated weighting factors were relatively small (in the range from 0.1 to 0.3).ConclusionsAccurate weighting factors representing the environmental attitudes of the Japanese public are needed in order to conduct general-purpose LCA for Japanese products. Random, unbiased sampling throughout Japan and an interview survey carried out on 1,000 respondents enabled us to address and solve the problems found with past weighting methodologies. We confirmed that the results of comparisons carried out among safeguard subjects were statistically significant, and showed that the contents of the questionnaires were well understood by the respondents. This study succeeded in visualizing the variability between each individual’s environmental thoughts in order to improve the transparency of the weighting factors—expressing the difference in individual preferences within a certain range. This data can be used to develop integration factors with statistical values which can then be applied to uncertainty analysis in future LCA case studies.

Does Social Capital Encourage Participatory Watershed Management? An Analysis Using Survey Data From the Yodo River Watershed

Increasing attention is being paid to participatory watershed management, ranging from participation in administrative decision-making concerning larger-scale watersheds to participation in substantial management activities in smaller-scale watersheds. This article argues that individual participatory behavior in watershed management is affected by social capital and examines the effects of four different types of social capital using survey data from the Yodo River watershed in Japan. Our findings suggest that social capital has an impact on participation in watershed management, but it functions differently according to type of social capital. Notably, analysis reveals adverse effects between bonding social capital and bridging social capital on participation in government-led activities. This finding implies the need to examine the effects of social capital by type, and signals caution that present participants in activities by government are skewed toward those who possess bridging structural and cognitive social capital.

Measuring consumer preferences regarding organic labelling and the JAS label in particular

Abstract This study aims to examine whether Japanese consumers show a preference for particular types of food certification, particularly the organic Japanese Agricultural Standards (JAS) label, and how important certification of food products is compared to their freshness and source. Organic JAS certification is a certification system with government‐backed legal foundations. To consider these issues, we conducted a willingness to pay (WTP) survey for vegetables (spinach) as food products with a choice experiment (CE). The vegetables presented in the CE had four attributes: freshness, source, price, and certification. As a result, we found that Japanese consumers valued food certifications and had a WTP for them, including the JAS label. On the other hand, certification was a smaller factor than freshness and source in vegetable purchasing criteria. Freshness was the most important factor for Japanese consumers.

Measuring marginal willingness to pay using conjoint analysis and developing benefit transfer functions in various Asian cities

ABSTRACT We need a consistent methodology to measure the co-benefits of climate change mitigation across Asian countries. This study chose a strategy of modifying the Japan-specific life-cycle impact assessment method based on endpoint modeling (LIME) for wider application across countries. LIME has two dimensions. First, it is an environmental science that links the cause-and-effect chain. Second, it is an environmental valuation that weighs four endpoint damages in monetary terms through a conjoint analysis that is derived from an Internet-based questionnaire survey. This article describes the modification of the methodology for application of the conjoint analysis to weigh environmental impacts. We approached the investigation as follows. First, we conducted Internet surveys to measure marginal willingness-to-pay (MWTP). We used a sample of 112 respondents in their 20 s to 40 s, divided equally between men and women, in 11 cities across China, India, and Southeast Asia. The results obtained showed clear statistical significance and were comparable across the cities. Second, we attempted to develop functions (called benefit transfer functions) to simplify the measured MWTP in order to apply it across different Asian countries. The functions were derived through a stepwise meta-analytic method, a type of multiple regression analysis whose independent variable was MWTP and dependent variables were attributes of both respondents and surveyed cities. The functions showed that coal consumption and percentage of nature reserve were dependent variables. Then, the MWTPs estimated from the functions were compared with the measured MWTP for transfer error, which is calculated by the absolute value of the difference between the estimated value and the measured value divided by the latter. The transfer error was below 50% in about 90% of the 44 results (a combination of four endpoints and 11 cities), implying that the developed functions were statistically significant.

Consumer Preferences for Organic Products in Austria Using Stated Preference Methods

In this study, we focused on estimating Austrian consumer preferences or willingness to pay for organic prod- ucts using stated preference methods: choice experiment and contingent valuation. Austria is a pioneer country in organic farming, and has an advanced market for organic food products in Europe. Therefore, it is meaningful to investigate their consumer preferences for organic foods. The results of the choice experiment showed that Austrians, in particular females, have a preference and are willingness to pay a price premium for domestically-grown organic vegetables. The results of contingent valuation also showed that they have a preference and are willing to pay for organic food materials in the case of eating out, restaurants or cafe, etc.

A Study on Japanese Consumers ’ Preferences for Agricultural Spinach as Fresh Foods

We can often find organic foods or foods with no chemical fertilizers in the supermarket. Japanese people pay attention to food safety, and want to get information about its quality. The purpose of the paper is to reveal Japanese consumers ’ preferences for agricultural spinach as fresh foods and preference heterogeneity among them. When they purchase it, what attribute they emphasize? Are they sensitive to price or quality of it? We assumed that their preferences are divided into few groups. Thus, we try to confirm this by using choice experiments (CE). The results revealed that there are economic benefits of organic products and local consumption of locally produced foods. On the other hand, the results indicated that there is a significant heterogeneity among Japanese consumers preferences for agricultural spinach as fresh foods.

Quantifying Japanese Residents’ Preferences for Public Meetings in Watershed Decision-Making Process

In this article, we quantified Japanese residents’ potential preferences for public participation, specifically public meetings, concerning regional environmental issues in Yodo River watershed decision-making process. We conducted a choice experiments (CE) survey in the Yodo River watershed in Japan. Our findings confirmed that residents assign a certain value to public participation, in particular, public meetings. We also found that when residents are given opportunities to speak, they show a strong desire to have experts and, especially, government officials in charge to be present at the meetings. Thus, we indicated Japanese residents’ potential preferences for public meetings using the CE with discrete choice model.