Adolescents' sustainability concerns and reasons for not consuming sustainably

Many consumers report being concerned about sustainability but they do not necessarily consume in a sustainable manner. Understanding why this occurs is vital to encouraging sustainable consumption practices. Understanding the phenomenon in relation to adolescents is particularly important. In addition to being a significant segment of current consumers, adolescents are learning consumption habits and preferences that they will carry into adulthood. This research contributes to the domain by fulfilling two research objectives. The first objective was to develop and use a scale for measuring adolescents' sustainability concerns (ASC). The second objective was to identify and examine adolescents' reasons for not consuming sustainably. The research used a three‐stage multi‐method design that included small group interviews and two online surveys with adolescents aged 12 to 17 years. The ASC scale that we produced identifies 14 key sustainability concerns across the dimensions of environment, well‐being and society. The reasons for not consuming sustainably varied across these dimensions. For example, the most frequently reported reasons in the environmental dimension included cost and convenience whereas peer pressure and hedonic preferences were the dominant reasons for well‐being. More broadly, three groups of reasons for unsustainable consumption emerged. These included (i) limited application of sustainability concerns across consumption; (ii) deviating from concerns due to competing priorities; and (iii) limiting or eliminating personal responsibility. The contributions of this research have theoretical, methodological and practical implications for consumer researchers, social marketers and policy makers.     

Segments of sustainable food consumers: a literature review

Sustainable food consumption is an important aspect of sustainable development. When adopting a sustainable food lifestyle, consumers are confronted with complex choices. Today's food consumption is too complex to be explained by socio‐demographic factors exclusively. A broader perspective is needed. In order to explain behaviour across different consumer segments better, relatively homogenous segments of food consumers were identified by segmenting food consumers based on a wide range of variables. The current study aims to provide an overview of published studies that have segmented consumers with regard to sustainable food consumption. The literature review has been conducted by searching SciVerse Scopus for all relevant articles available until November 2010. The main criterion for including a specific study was the inclusion of empirical analyses of primary data, resulting in consumer segments with regard to sustainable food consumption. Sixteen articles were incorporated in the final analysis. First, the variables used for segmentation and profiling in the included articles have been categorized into three levels of abstraction: personality characteristics, food‐related lifestyles and behaviour. The three levels of abstraction proved to be helpful in categorizing the segmentation studies. The findings indicate that variables on all three levels were efficient in differentiating consumer segments regarding sustainability. In addition, the importance of price and health differed across the segments, although these variables are only indirectly related to sustainability. Second, the three most frequently identified consumer segments with regard to sustainable food consumption were: ‘greens’, ‘potential greens’ and ‘non‐greens’. These segments differed from one another on all three levels of abstraction. This implies that future segmentation studies should include variables on all levels of abstraction to get a complete picture of existing sustainable consumer segments. Marketers should be aware that targeting specific segments based on socio‐demographic variables exclusively is not sufficient. Personality characteristics, lifestyle and behaviour are all important to take into consideration. Attempts at stimulating sustainable consumption might be most effective when differences across consumer segments are taken into account. Future research is needed to explore the characteristics of different sustainable food consumer segments with respect to their potential contributions in promoting sustainable development.     

Multi-period stochastic optimization of a sustainable multi-feedstock second generation bioethanol supply chain − A logistic case study in Midwestern United States

This work proposes a multi-objective optimization model to design a sustainable multi-period second generation biomass-to-bioethanol supply chain under multiple uncertainties. The objective is to simultaneously maximize the economic, environmental, and social performance. The strategic decisions such as land allocation for switchgrass cultivation, biorefinery locations and capacities, and the biomass-to-bioethanol conversion pathway are determined for each planning period which are staggered across the entire planning horizon. The augmented ε–constraint method is used to trade-off among the competing objectives and to obtain feasible solutions that achieve desired levels of sustainability. In order to solve the proposed stochastic optimization model efficiently and effectively, this work proposes a solution approach involving sequential application of a modified Sample Average Approximation method and Benders decomposition. A case study is presented to demonstrate the effectiveness of the proposed mathematical model and its impact on land usage and sustainability.     

Sustainability assessment methodology of urban mobility projects

In Brazil, the introduction of a national urban mobility policy occurred only in 2012. In this context, the federal government has provided hundreds of millions in investment to improve mobility conditions in urban areas. The main financial institution responsible for analyzing and monitoring developments of this nature considers the following criteria for project assessment: cost, environmental licensing, compatibility, and functionality. However, a project’s contribution to sustainable urban mobility is not taken into account. Thus, the work reported herein aimed to develop a method to assess the sustainability of urban mobility projects. This involved indicator selection, and the development of a tool based on sustainability indicators for project assessment. In addition, an Urban Mobility Project Sustainability Index (UMPSI) was proposed to summarize the assessment, which was tested in five urban mobility projects funded in the Curitiba Metropolitan Region (RMC), presented in a companion paper. Environmental, social, and economic aspects of project design and implementation are considered in the assessment. The proposed method consists of 17 sustainability indicators, grouped according to their connection with environmental, social, and economic aspects. Addition of the proposed method to the contracting and monitoring processes of future urban mobility projects supports the sustainable development of the urban landscape.     

The role of forecasting in sustainability

A lack of understanding of the waste flow of durable goods complicates decision-making efforts that will increase sustainability. To address this problem, the modeling of the waste flow of durable goods is considered. Televisions are used to illustrate the requirements for forecasting and the magnitude of the associated uncertainty of the waste flow for a durable good that is impacted by technological change and/or unpredictability in field life. This example is timely due to disposal laws affecting cathode ray tubes (CRTs) and the emergence of alternate technology trajectories for televisions. The findings suggest that the reuse of lead-bearing CRT glass is worthwhile, even though flat panel TV technology will eliminate this controversial waste stream. The findings also indicate the implications of forecasting durable waste flows for decisions regarding policy, business models, required infrastructure and supply chain management.     

The water footprint of energy from biomass: A quantitative assessment and consequences of an increasing share of bio-energy in energy supply

This paper assesses the water footprint (WF) of different primary energy carriers derived from biomass expressed as the amount of water consumed to produce a unit of energy (m³/GJ). The paper observes large differences among the WFs for specific types of primary bio-energy carriers. The WF depends on crop type, agricultural production system and climate. The WF of average bio-energy carriers grown in the Netherlands is 24 m³/GJ, in the US 58 m³/GJ, in Brazil 61 m³/GJ, and in Zimbabwe 143 m³/GJ. The WF of bio-energy is much larger than the WF of fossil energy. For the fossil energy carriers, the WF increases in the following order: uranium (0.1 m³/GJ), natural gas (0.1 m³/GJ), coal (0.2 m³/GJ), and finally crude oil (1.1 m³/GJ). Renewable energy carriers show large differences in their WF. The WF for wind energy is negligible, for solar thermal energy 0.3 m³/GJ, but for hydropower 22 m³/GJ. Based on the average per capita energy use in western societies (100 GJ/capita/year), a mix from coal, crude oil, natural gas and uranium requires about 35 m³/capita/year. If the same amount of energy is generated through the growth of biomass in a high productive agricultural system, as applied in the Netherlands, the WF is 2420 m³. The WF of biomass is 70 to 400 times larger than the WF of the other primary energy carriers (excluding hydropower). The trend towards larger energy use in combination with an increasing contribution of energy from biomass will enlarge the need for fresh water. This causes competition with other claims, such as water for food.     

Significance of environment in the assessment of sustainable development: The case for south west Victoria

The assessment of sustainable development is often based on the three pillars of sustainability model using social, economic and environmental indicators. It is thought that by measuring the performance of each system, information can be gained about the sustainability of the whole system. However it seems there has been no attempt to evaluate if such an assumption is true. During the development of a sustainability assessment framework for south west Victoria, Australia, it has become evident that this approach to sustainability assessment does not provide an accurate assessment of system sustainability. The project found that environmental indicators were considered the most important for assessing regional sustainability. As a consequence, the assessment produced shows that in south west Victoria, sustainability is largely determined by the condition of the environment. This finding highlights the current disconnection between the theory and reality of sustainability. Here, we describe a framework for sustainability assessment that attempts to re-connect theory to practice.     

降低养老保险缴费率：“一举两得”抑或“得不偿失”？——基于缴费遵从度与基金可持续的视角

2019年以来我国实施一系列"减税降费"政策以激发市场主体活力，例如城镇职工基本养老保险政策缴费率由28%降至24%，下调养老保险政策缴费率能提高缴费遵从度吗？养老保险基金可持续性又将发生何种变化？文章基于2002-2019年省级面板数据，运用计量模型和精算模型得到如下结果：（1）当养老保险政策缴费率每降低1个百分点，缴费遵从度会上升3.117个百分点；（2）如果养老保险政策缴费率仍为28%，基金分别于2021年和2026年开始出现当期赤字和累计赤字，2030年和2050年累计赤字规模分别为13.89万亿元和280.36万亿元；（3）若养老保险政策缴费率下调4个百分点，缴费遵从度上升12.468个百分点，养老保险基金开始出现累计赤字时点向后推迟1年至2027年，2030年和2050年累计赤字规模分别减少29.67%和8.14%；上述结论均通过稳健性检验和敏感性测试。综上所述，降低养老保险政策缴费率既能提高缴费遵从度，又能促进养老保险基金可持续运行，是一项"一举两得"的政策。