Historical effects of shocks on inequality: the great leveler revisited

The paper scrutinizes the widely cited “great leveler” hypothesis, which posits that catastrophic shocks (e.g., pandemics, wars, revolutions, natural disasters) are the primary drivers of reductions in inequality. It asks under what conditions shocks reduce versus amplify inequality. Drawing on debates around the Black Death, and modern work by Scheidel, Piketty, and Milanovic, the authors contend that while some shocks temporarily reduced inequality, most disasters ultimately increased wealth disparities. They set up a framework separating immediate impact, medium-term institutional responses, and long-run effects, arguing that pre-disaster wealth distribution and political leverage largely determine outcomes.

The article surveys major strands of scholarship: Scheidel’s thesis that only violent or catastrophic events reduce inequality; Piketty’s emphasis on the equalizing effects of the World Wars via destruction and progressive taxation; Milanovic’s view that pre-industrial inequality declines were typically driven by exogenous shocks. It reviews historical debates on the Black Death, including Malthusian interpretations (Postan) and quantitative evidence showing wage increases and temporary wealth compression (e.g., Alfani’s Italian data; Pamuk on real wages). It contrasts regional trajectories: Northwestern Europe’s greater freedom and higher wages post-Black Death versus Southern Castile’s concentration via large estates and Northeastern Europe’s later imposition of serfdom. The review extends to disasters such as famines and floods, highlighting mechanisms of asset loss, forced sales, and consolidation (e.g., England c.1300 crises; Great Famine; North Sea floods), and modern political economy work on power and institutions (e.g., Kashwan et al., Gilens and Page).

The study is a critical historical review and comparative analysis spanning medieval to contemporary periods. It synthesizes large historical datasets and case studies from Europe (e.g., Italy, Low Countries, England, Eastern Europe), using a three-stage analytical framework: (1) immediate impact of shocks shaped by pre-existing wealth distributions and institutions; (2) medium-term institutional responses shaped by political leverage; (3) long-run, path-dependent outcomes, including carry-over effects to subsequent shocks. The authors deploy comparative within-region and across-time analyses (e.g., Italian plagues of 1347–1352 vs. 1629–1631; Low Countries’ recurrent floods 1300–1800) to hold geography constant while tracing institutional variation. Conceptual diagrams (stability landscapes and feedback schemes) illustrate how leverage and institutional settings modulate trajectories of inequality.

• Most historical shocks were followed by widening wealth gaps. Wealthy actors’ buffers and leverage enabled them to weather crises and acquire assets from distressed households, leading to consolidation.
• Two determinants govern outcomes: (a) pre-shock wealth distribution (buffers, market access) and (b) political leverage (ability to set post-crisis rules). Their interaction typically yields disequalizing institutional responses where elites dominate.
• Black Death (1347–1352): mortality up to ~50% in Eurasia; short-run wage gains and some wealth compression in parts of Europe; long-run divergence. Northwestern Europe saw greater freedom and higher real wages; parts of Italy initially reduced wealth inequality but later elite legal innovations (e.g., fiduciary entails) preserved estates; Northeastern Europe trended towards renewed coercion and, in places, serfdom.
• Italy’s 1630 plague (mortality roughly one-third) lacked equalizing effects and was followed by rising inequality due to entrenched elite institutions and inheritance constraints protecting large properties.
• Floods and famines: while initial destruction could level wealth, long-run effects generally increased inequality through forced land sales, high repair costs, and elite-led reinvestment consolidating absentee ownership (e.g., North Sea coastal areas, 1509 Dollard flood, 1717 storm flood).
• Carry-over effects: institutional responses to one disaster shape vulnerability and leverage for subsequent shocks. Egalitarian, participatory water management increased resilience and equity; elite-dominated settings showed non-adaptation, repeated disasters, and further polarization.
• Twentieth century: World Wars and the Great Depression reduced inequality primarily via political contexts with strong organizations of ordinary people that enabled progressive inheritance and wealth taxes and the creation of social security systems; equalization persisted into the 1970s.
• Post-1970s: oil crisis used to legitimize deregulation and privatization; weakening of organized labor; subsequent 2008 financial crisis increased inequality as policy responses (bank rescues, monetary expansion) prioritized financial stability, benefiting asset holders.
• COVID-19 outlook: given post-2008 increases in wealth and political concentration, absent strong countervailing organizations, responses are likely to further raise inequality.

The findings challenge the “great leveler” narrative by showing that shocks do not inherently reduce inequality. Instead, outcomes hinge on pre-existing wealth buffers and on who holds decision-making leverage when institutions are reshaped after crises. Where elites dominate, policy and legal changes (labor laws, tax structures, inheritance rules, property regimes) tend to entrench or accelerate inequality. Conversely, where ordinary people are organized (guilds, commons organizations, unions, cooperatives, political movements) and possess leverage, crises can become windows for equalizing institutional reforms (e.g., progressive taxation, inclusive governance). The analysis underscores path dependence: institutional responses to one crisis determine future vulnerability and leverage distributions, shaping the impact of subsequent shocks. This framework explains both medieval divergence after the Black Death and modern shifts from mid-20th-century equalization to late-20th and early-21st-century re-concentration of wealth.

The paper offers a unifying framework explaining why most shocks historically catalyzed inequality: wealth buffers and skewed political leverage allow elites to shape post-crisis institutions in their favor. Exceptions arise when strong, broad-based organizations of ordinary people enable equalizing responses. The authors reinterpret well-known episodes (Black Death, Italian plagues, floods, 20th-century wars, 2008 crisis) through this lens and visualize dynamics via stability landscapes and carry-over feedbacks. Future research should: (1) further quantify the role and measurement of political leverage and associational power across contexts; (2) disentangle causal effects of specific institutional changes from broader socio-economic dynamics over long timescales; (3) incorporate multi-scale tipping points and poverty traps into models of inequality; and (4) expand beyond Europe to test generality. Policy implications suggest that building and sustaining inclusive institutions and organizations prior to crises is crucial for steering post-shock trajectories toward equity.

• Data constraints: for some regions and periods (e.g., parts of Northeastern Europe), direct measures of wealth distribution and immediate post-shock impacts are sparse, limiting precision.
• Causal disentanglement: institutional responses and broader socio-economic dynamics co-evolve, making it difficult to isolate the effect of a given shock or reform.
• Modeling simplifications: conceptual diagrams and simple inequality models rely on single-index measures (e.g., Gini) and omit multi-dimensional dynamics (e.g., poverty traps, thresholds, sectoral heterogeneity) and organizational emergence.
• External validity: many cases are European; broader comparative studies beyond Europe are needed to assess generality.
• Temporal scale: long-run feedbacks and carry-over effects are complex and may be influenced by global shifts (e.g., globalization) not fully captured in historical case syntheses.