What Is Happening
Japanese social policy research underwent a fundamental transformation at the turn of the late 1990s. The postwar consensus of "100-million-strong middle class" (ichioku sōchūryū) collapsed, and inequality, poverty, and social exclusion emerged as central issues in both academic and policy arenas. Yet this was not merely a change of topic. It was a transformation of the very frameworks used to describe society — a restructuring of the intellectual foundations that determine "what counts as a problem."
The method ISVD employs as its standard article structure — "What Is Happening → Background and Context → Reading the Structure" — aims at intervention through the visualization of social structures. This approach differs from academic social policy research, but the two are not unrelated. This note maps the intellectual lineage of Japanese social policy research and locates ISVD's methodology within it.
Background and Context
Pre-war Origins: The Social Policy Association and Ōkōchi's Theory
The institutional origin of social policy research in Japan traces back to the Social Policy Association (Shakai Seisaku Gakkai), established in 1896. Modeled on German Kathedersozialismus (professorial socialism), its starting point was the concern to mitigate the ills of capitalism through state intervention.
After the war, it was Kazuo Ōkōchi who theoretically reconstructed this tradition. Ōkōchi's "labor-power preservation theory" (rōdōryoku hozensetsu) positioned social policy as the cost of reproducing labor power necessary for maintaining the capitalist system. While theoretically sophisticated in explaining social policy through the logic of capital accumulation rather than moral imperatives, this framework tended to abstract policy subjects as "labor power," thereby placing the concrete experiences and lives of individuals outside its analytical scope.
The "100-Million Middle Class" Consensus and Its Collapse
What long defined postwar Japanese social policy discourse was the social perception of ichioku sōchūryū — the "100-million-strong middle class." From the 1970s onward, when approximately 90% of respondents in the Cabinet Office's "Public Opinion Survey on People's Lives" identified their standard of living as "middle," the premise that Japanese society had minimal inequality became widely shared.
Under this premise, arguments for strengthening redistribution policies were easily marginalized in both political and academic spheres. In a "society without inequality," the intellectual frameworks needed to problematize inequality are deemed unnecessary. Here one can read an agnotological structure: the invisibilization of inequality was achieved not through the concealment of data but through the maintenance of a social consensus that "inequality does not exist."
Toshiaki Tachibana: The First Challenge to the Equality Myth (1998)
It was Toshiaki Tachibana (橘木俊詔) who directly challenged this consensus with Nihon no Keizai Kakusa (Japan's Economic Inequality, 1998, Iwanami Shinsho). Through time-series analysis of the Gini coefficient, Tachibana empirically demonstrated that income inequality in Japan had been on an upward trend since the 1980s.
The significance of this work extends beyond the presentation of data itself. It opened a channel for academically questioning the tacit premise that "Japan is an equal society." Income distribution data had existed before Tachibana, but the framework for reading it as "widening inequality" was not socially shared.
The Tachibana–Ōtake Debate: What Are We Measuring?
Tachibana's challenge was refined through his debate with Fumio Ōtake (大竹文雄). In Nihon no Fubyōdō (Japan's Inequality, 2005), Ōtake argued that a substantial portion of the Gini coefficient increase was "apparent inequality growth" attributable to aging and changes in household structure — particularly the rise of single-person households.
This debate illuminated the politics of measurement in social policy research. When contradictory conclusions are drawn from the same data, the question is not simply "which is correct" but rather "what do we choose as the object of measurement?" and "which decomposition method do we select?" Prioritizing demographic decomposition relativizes the expansion of inequality; focusing on intra-generational inequality reveals its intensification. The choice of measurement framework itself determines the visibility of the problem.
Zen'ichi Kenjoh: The Political Economy of Redistribution
Given that inequality exists, why do redistribution policies not function adequately? It was Zen'ichi Kenjoh (権丈善一) of Keio University who tackled this question from a political economy perspective. Kenjoh's works, including Chotto Ki ni Naru Shakai Hoshō (A Casual Look at Social Security) and especially his seven-volume Saibunpai Seisaku no Seiji Keizaigaku (Political Economy of Redistribution Policy), presented a framework for analyzing social security systems not as "policy technology" but as "products of political processes."
Kenjoh's core insight is that the design of social security systems is determined not solely by economic rationality but by political dynamics — negotiations among stakeholders, shifts in public opinion, and institutional path dependency. When a system appears "inefficient," it can often be rationally explained as the outcome of political processes rather than design failure.
This perspective carries important implications for ISVD's analysis. To "read the structure" of social problems means not merely pointing out technical deficiencies of institutions, but understanding in political-economic terms why those institutions exist in their current form.
Tarō Miyamoto: Japan's Welfare Regime Theory
Tarō Miyamoto (宮本太郎) occupies the most significant position as the scholar who connected comparative welfare state theory to the Japanese context. After analyzing the strategic character of the Swedish welfare state in Fukushi Kokka to iu Senryaku (The Welfare State as Strategy, 1999), Miyamoto continued with Fukushi Seiji (Welfare Politics, 2008), Seikatsu Hoshō (Livelihood Security, 2009, Iwanami Shinsho), and Kyōsei Hoshō (Symbiotic Security, 2017, Iwanami Shinsho), consistently interrogating the positioning and reconstruction of Japan's welfare state.
Miyamoto's intellectual foundation rests on Esping-Andersen's welfare regime typology. In The Three Worlds of Welfare Capitalism (1990), Esping-Andersen classified the welfare states of advanced capitalist nations into three types: liberal, conservative, and social-democratic regimes. Within this framework, Japan was long positioned as a "hybrid" that did not fit neatly into any single type.
Miyamoto's contribution lies in not treating Japan's hybrid character as a mere classificatory exception but actively analyzing the distinctive logic of Japanese-style welfare — dependence on corporate welfare and family welfare, the structure of "security through employment." In Livelihood Security, he presented the concept of seikatsu hoshō (livelihood security) that integrates employment and social security. In Symbiotic Security, he further articulated the direction of "transcending the fixation of supporter and supported roles."
International Context: Piketty and the Rediscovery of Inequality
Internationally, Thomas Piketty's Capital in the Twenty-First Century (2013) elevated inequality research from academic periphery to political center. Piketty's r > g proposition — that the rate of return on capital structurally exceeds the rate of economic growth — demonstrated that widening inequality is not a policy failure but an intrinsic tendency of capitalism.
Piketty's contribution extends beyond theoretical propositions. His construction of the World Inequality Database (WID.world) is significant for building data infrastructure for inequality research. If the absence of data produces the invisibility of problems, then constructing databases is itself an act of intervention.
Makoto Yuasa: Visualizing the "Sliding-Door Society"
From a different channel than academic research, Makoto Yuasa (湯浅誠) made inequality and poverty visible. In Han Hinkon (Anti-Poverty: Escape from the "Sliding-Door Society", 2008, Iwanami Shinsho), Yuasa's concept of the "sliding-door society" (suberidai shakai) sharply visualized the structural defects of Japan's social security system.
According to Yuasa's analysis, Japan's social security consists of three layers — employment insurance, social insurance, and public assistance — but there is no "reservoir" (buffer) between them. Once one falls out of regular employment, one slides through employment insurance and directly down to the public assistance level. Intermediate safety nets are institutionally absent.
The intellectual significance of the "sliding-door society" lies in naming the structural character of the "gaps" between institutions, rather than individual deficiencies of each system. This was a practical breakthrough against what Fricker calls hermeneutical epistemic injustice — the inability to recognize a problem because society lacks the concepts to articulate it. Through the creation of the "sliding-door society" concept, experiences that had been processed as individual misfortune became visible as structural problems.
Reading the Structure
The Methodological Difference Between Social Policy Research and ISVD
Surveying the intellectual lineage above, social policy research can be seen to possess three methodological characteristics.
First, empirical measurement. Tachibana's Gini coefficient analysis, Piketty's long-term time-series data, and Ōtake's demographic decomposition are all attempts to quantitatively grasp the phenomenon of inequality.
Second, institutional analysis. Kenjoh's political economy, Miyamoto's welfare regime theory, and Esping-Andersen's typology analyze the structure and dynamics of social security systems.
Third, concept creation. Yuasa's "sliding-door society," Miyamoto's "livelihood security" and "symbiotic security" make visible realities that existing frameworks could not capture through new concepts.
ISVD's methodology is closest to this third characteristic — visualization through concept creation. However, there is a decisive difference. Whereas concept creation in academic social policy research is directed at fellow researchers through papers and books, ISVD's "Reading the Structure" aims at transforming citizens' perception through the methods of information design — data visualization, article composition, and diagrams. Visualization not as explanation, but as intervention.
The Politics of Measurement Revealed by the Tachibana–Ōtake Debate
The Tachibana–Ōtake debate contains a methodologically important lesson for ISVD's work. The fact that contradictory conclusions — "inequality is expanding" versus "no, that is apparent change" — were drawn from the same statistical data demonstrates that data presentation alone does not resolve problems.
The same issue arises in the context of EBPM (Evidence-Based Policy Making). In evidence-based policymaking, "what counts as evidence" and "which analytical framework is used to interpret data" are often political choices. ISVD's insistence on including a "Reading the Structure" section when presenting data visualizations rests on the recognition that data presentation alone is insufficient — an interpretive framework must be provided simultaneously.
Piketty's Data Infrastructure and ISVD's e-Stat Utilization
What Piketty achieved through WID.world was the democratization of inequality data. By enabling researchers worldwide to access long-term time-series income and wealth data, the entry barrier for inequality research was dramatically lowered.
ISVD's attempt to build statistical dashboards using the e-Stat API rests on the same logic, albeit at a different scale. Japan's public statistical data is publicly available, but significant barriers exist in terms of accessibility and interpretability. The existence of data and the visibility of data are not synonymous. ISVD's dashboards, by making already-published data "visible," position visualization itself as an act of intervention.
Miyamoto's "Symbiotic Security" and ISVD's Structural Approach
The direction Miyamoto articulated in Symbiotic Security — "transcending the fixation of supporter and supported roles" — resonates with the concern at the root of ISVD's work. In social design, those affected by social problems are simultaneously "subjects" of analysis and "agents" of structural transformation.
However, ISVD's approach has a different scope from Miyamoto's argument. Where Miyamoto envisions "symbiotic security" through the institutional design of the welfare state, ISVD pursues structural transformation through the design of information environments — how things are seen and what becomes visible. Institutional change and perceptual change are complementary but not identical.
Remaining Questions
First, there is the practical challenge of how to translate the empirical knowledge accumulated by social policy research into ISVD's articles and visualizations. The precision of academic papers and the accessibility of information design for citizens are often in a trade-off relationship.
Second, while there are success stories like the "sliding-door society" where concept creation changed social perception, there is a risk that as concepts circulate, their original analytical precision erodes. Methodological safeguards are needed to prevent the analytical frameworks presented in ISVD's "Reading the Structure" from being reduced to mere catchphrases.
Third, there is the integrative challenge of how the lineage of social policy research covered in this note connects with the intellectual lineage from agnotology to structural invisibility. The invisibility of inequality (social policy) and the production of ignorance (agnotology) are, in ISVD's methodology, different facets of the same phenomenon. This integration remains a task for this research lab.
→ Related: Social Design Foundations Lab: Hypothesis Overview | Literature Map: From Agnotology to "Structural Invisibility"
