This study aims to develop an empirical measurement framework of the green state and compare twenty-four OECD (Organization for Economic Cooperation and Development) countries’ cases through the fuzzy-set multiple conjunctural analysis and the ideal type analysis. Based on the analysis model of the outcome set (Sustainable Development Goal Index) and the causal sets of seven variables on the four green state categories (‘ecological authoritarian state’, ‘ecological modern state’, ‘ecological democracy state’, and ‘ecological welfare state’), this study reveals the following results. Among OECD member countries, if ones have high environmental tax, high environmental innovation (patent), high economic development and democracy, high levels of environmental governance and social expenditure, or have high economic development and democracy, and high levels of environmental governance and environmental health, they can be seen to have reached a high level of green state (consistency: 0.980, total coverage: 0.675). Also, the thirteen ideal types of green state of twenty-four OECD countries were derived. Norway (fuzzy-set membership score of 0.515) is a country of Type 1, with a characteristic of ‘strong green state’ having all high features of the four green state categories. Greece (membership score, 0.692) and Ireland (0.577) belong to Type 13, characterized by ‘weak green state’ with all four low features. As a result, the green state types of the twenty-four OECD countries can be assorted into five levels: ‘Strong Green State’, ‘Quasi-Strong Green State’, ‘Quasi-Green State’, ‘Quasi-Weak Green State’, and ‘Weak Green State’.

This study aims to explore the influencing factors of multidisciplinary digital social innovation (DSI) in the OECD (Organization for Economic Cooperation and Development) member countries in light of the socio-technical system transition theory. It sets up the eight variables of the four areas that comprise the DSI, and then identifies the causal conditions (arrangements) based on the empirical findings through the fuzzy-set multi-conjunctural analysis. In short, it concludes that, if OECD member countries have high level of democracy and e-participation, high GDP and business-friendly environment, high social expenditure, and high level of ICT (Information and Communication Technology) development and patent applications, they are highly likely to achieve a sufficient level of digital social innovation. This study underlines that the result of combined arrangement explains that the DSI can be more properly characterized by the multi-level and structured approach of the socio-technical system transition that goes beyond the fragmentary approach of existing innovation theories and the current related academic field. Moreover, this study reveals that the social factors (including the social capital variable) that have attracted attention from previous studies may have little effect on the DSI. In essence, it suggests that citizen interaction and social change can be newly formed through technological innovation in a multi-dimensional way, and that more in-depth discussion regarding the new context of ‘digital citizen’ might be required.

This study aims to analyze the global trends of energy mix and energy transition from a chronological view (from Y1995 to Y2015) and identify the actual results based on the empirical findings. It sets up a measurement framework of energy mix (four energy sources: fossil fuel (F), hydroelectric (H), renewable (R), and nuclear (N)), and compares thirty-four Organisation for Economic Cooperation and Development (OECD) countries’ cases through the fuzzy-set ideal type analysis. In short, twelve ideal types of energy mix of the thirty-four OECD countries were derived in Y1995; eleven ideal types in Y2000, thirteen ideal types in Y2005, twelve ideal types in Y2010, and fifteen ideal types in Y2015, respectively. This study particularly reveals the gradual change of the features of energy transition, although an epoch-making trend of overall energy transition in OECD countries is not identified. For example, from1995 to 2010, in the case of Type 7 (F*h*r*N) with a characteristic of ‘pan-conventional energy-centered mix’ having two high features (F, N), and of Type 8 (F*h*r*n), characterized by ‘fossil fuel-centered energy mix’ with one high feature (F), seven to eight countries were steadily included, but in 2015 there was a significant decrease to four countries (solely Type 7). Throughout the five stages from 1995 to 2015, the type with the largest number of countries (20) was Type 10 (f*H*R*n, ‘pan-renewable energy-centered type’) led by hydroelectric (H) and renewable energy sources (R), followed by the second most, Type 12, (f*H*r*N, ‘hydro & nuclear-centered type’, characterized the high features of H and N) with nineteen countries.