Researcher Directory

Pioneering agent-based modeling of financial markets, technology forecasting using Wright's Law, housing market ABMs, and making the case that complexity economics can generate actionable policy. Author of "Making Sense of Chaos" (2024).

Founding complexity economics as a field. Increasing returns, path dependence, lock-in, the El Farol Bar Problem. First to articulate that the economy is not in equilibrium but constantly evolving and computing.

Best synthesizer of complexity economics for a general audience via "The Origin of Wealth" (2006). Articulated the economy as an evolutionary system. Connecting complexity econ to policy and prosperity.

Heterogeneous agent models with bounded rationality in financial markets. Showed that simple behavioral switching rules between strategies can generate realistic market dynamics including bubbles and crashes.

Defining and formalizing Agent-based Computational Economics (ACE) as a methodology. Created the ACE website, the definitive resource. Pioneered ABM in energy/electricity market design.

Building the Santa Fe Artificial Stock Market with Arthur and Palmer. Demonstrated that heterogeneous agents with adaptive learning generate realistic financial time series including fat tails and volatility clustering.

Scaling agent-based models to hundreds of millions of agents. Co-created Sugarscape with Epstein. Showed firm size distributions emerge from agent interactions. Built largest-ever ABM of the entire US economy.

Evolutionary economics and innovation. The K+S (Keynes+Schumpeter) agent-based model connecting micro-level innovation dynamics with macro-level business cycles. Technology paradigms and trajectories.

Empirical validation of agent-based models. International trade networks analysis. Co-developer of the K+S model with Dosi. Bridging ABMs and econometrics for credible policy simulations.

Climate-economy ABMs. Extended the K+S model to incorporate climate change, green transition policies, and fiscal/monetary interactions. Showing how complexity models can evaluate climate policy.

Agent-based macroeconomics. Financial fragility in ABMs. Connecting Minsky's financial instability hypothesis with complexity economics through computational models.

Agent-based models of financial markets with herding and contagion. Showed how switching between fundamentalist and chartist strategies generates realistic fat-tailed return distributions.

Demonstrating that the representative agent is a fundamental flaw in mainstream economics. Ant colony models of economic behavior. Bridge figure between general equilibrium theory and complexity.

Articulating the post-Walrasian research program and how complexity economics fits into the future of economic thought. Advocate for reforming economics education to include complexity.

Self-organization in economic systems. Energy and entropy approaches to economic dynamics. One of the earliest advocates for applying complexity science to economics from within the discipline.

Micro-meso-macro framework for evolutionary economics. Articulated how novelty and rules propagate through economic systems at different scales. Theoretical foundations of economic evolution.

Applying complexity economics to innovation policy and the creative economy. Network theory of economic evolution. Extending Dopfer's micro-meso-macro framework.

History and methodology of complexity economics. Mapping the intellectual networks and evolution of the complexity economics community itself. Scientometrics of the field.

Game-theoretic learning dynamics in complex environments. Housing market ABMs. Showing when and why agent-based models converge or don't to Nash equilibrium.

Bringing ABM to central banking. Agent-based models of the labor market. Using data science and complexity methods for official economic statistics and nowcasting.

Quantitative approaches to systemic risk using network science. Financial network topology. DebtRank algorithm for measuring financial institution systemic importance.

DebtRank — measuring systemic importance of financial institutions. Climate-finance stress testing. Network analysis of corporate control (the "network of global corporate control" paper).

Economic Complexity Index (ECI) and the Atlas of Economic Complexity. Showing that the productive knowledge embedded in a country's export basket predicts economic growth. Product Space.

Applying multiscale complexity analysis to economic and social crises — food prices, pandemics, ethnic violence. Showed how speculation drives food crises. Demonstrating real-world policy impact of complexity science.

Collective computation and intelligence theory. Articulating the deep connections between computation, adaptation, and economic behavior. Leading SFI's transdisciplinary complexity agenda.

Econophysics — applying statistical physics to financial markets. Random matrix theory in finance. Showing that markets are far from efficient with fat tails and volatility clustering rooted in physics.

Mathematical foundations of systemic risk. Endogenous market dynamics and feedback loops. Network models of financial contagion with rigorous mathematical treatment.

Co-founding econophysics. "An Introduction to Econophysics" with Stanley — the field's defining textbook. Hierarchical clustering of financial markets.

Co-founding econophysics. Scaling laws in economics — showed power laws in stock returns, firm growth, city sizes. Applied statistical physics methods to quantify universal patterns in economic data.

Scale-free networks in economics. Network reconstruction methods for financial systems. Trade network analysis and economic fitness complexity.

Economic Fitness and Complexity (EFC) — an alternative to Hidalgo's ECI. Developed fitness-complexity algorithm adopted by the World Bank for development forecasting.

Economic Fitness and Complexity framework. Applying fractal geometry and statistical physics to economic development. Adviser to the World Bank on complexity-based development metrics.

Bringing complexity science into central banking. "The dog and the frisbee" speech advocating simple rules for complex financial systems. Network analysis of systemic risk at the Bank of England.

Applied ecological network stability theory to financial systems. Showed that the same network structures that destabilize ecosystems destabilize banking networks. Hugely influential crossover paper with Haldane.

Agent-based modeling of social and economic systems. Economic network analysis. Brownian agent models connecting physics of active matter to economic dynamics.

Social physics and computational social science. Pedestrian dynamics applied to panic/crowd economics. FuturICT project proposing a "living earth simulator" for socio-economic systems.

Co-authored "An Evolutionary Theory of Economic Change" (1982) with Winter — the foundational text of evolutionary economics that directly inspired complexity economics.

Co-authored "An Evolutionary Theory of Economic Change" with Nelson. Routines as economic genes. Organizational capabilities. Foundational theory that economies evolve through variation, selection, retention.

Nobel laureate who co-founded the Santa Fe Institute. "More is Different" — the idea that complex systems have emergent properties not reducible to their parts. Catalyst for applying physics to economics.

Co-created Sugarscape with Axtell — "Growing Artificial Societies." Generative social science — "if you didn't grow it, you didn't explain it." Agent-based modeling of epidemics and civil violence.

Diversity-drives-innovation thesis. "The Difference" showed how diverse problem-solving groups outperform homogeneous expert groups. The Model Thinker. Complexity economics pedagogy at SFI.

Co-authored "Complex Adaptive Systems" with Page — the definitive SFI textbook. Computational models of markets and institutions. Active learning in economic games.

Leverage cycles — showing how endogenous leverage amplifies booms and busts. Connecting general equilibrium theory with complexity through collateral and default dynamics.

"The End of Theory" — arguing that agent-based models should replace equilibrium models for financial regulation. Built ABM for the Office of Financial Research to model systemic risk.

Dragon King theory — extreme outlier events that are predictable because they arise from amplifying feedback mechanisms. Log-periodic power law models for predicting financial crashes.

Critical transitions and tipping points in complex systems. Early warning signals for regime shifts — methods applicable to economic crises, climate tipping points, and social transitions.

Complex networks and phase transitions applied to innovation, technological evolution, and language. Synthetic biology approaches to understanding economic complexity.

Co-developed the Atlas of Economic Complexity with Hidalgo. Product Space theory — countries diversify into products near their current capabilities. Growth diagnostics framework.

Network propagation of economic shocks. Showed that microeconomic shocks can cascade through production networks to create aggregate fluctuations — connecting network science with macro. Nobel 2024.

Social and economic networks — definitive treatment of network theory in economics. Game theory on networks. How network structure shapes economic outcomes, diffusion, and inequality.

Scale-free networks and preferential attachment. Showed that many real networks (including economic) follow power-law degree distributions. "Linked" brought network science to a popular audience.

Small-world networks with Strogatz. "Six Degrees" showed how small-world structure matters for economic diffusion, organizational design, and information cascading.

Universal scaling laws from biology to cities and companies. Showed that cities and firms follow quantitative scaling laws — metabolic theory applied to economic systems. "Scale" (2017).

Urban scaling theory — cities as social reactors. Showed that innovation and wealth scale superlinearly with city size while infrastructure scales sublinearly. Quantitative urban economics.

EURACE — the first large-scale agent-based macroeconomic model for the European economy. Connecting ABM to actual policy simulation at continental scale.

EURACE@Unibi — a major policy-oriented agent-based macroeconomic model. Innovation-driven growth in ABMs. Regional economic dynamics and industrial policy through complexity lens.

EURACE financial market modules. Agent-based modeling of financial markets with realistic institutional features. Connecting ABM with financial engineering.

Stock-flow consistent agent-based models. Benchmark ABM integrating Keynesian macroeconomics with agent-based microfoundations. Bridging post-Keynesian and complexity economics.

Climate-economy interactions in ABMs. Machine learning for ABM calibration. Developing methods to make agent-based models empirically grounded and policy-relevant for climate transitions.

Agent-based models of production networks. Climate change and green transition ABMs. Network effects in input-output economics with heterogeneous firms.

Agent-based macroeconomic models with financial accelerator dynamics. Bankruptcy cascades. Connecting Minsky's financial instability hypothesis with network contagion in ABMs.

Comprehensive survey of agent-based models of financial markets from the physics perspective. Bridge figure documenting the state of ABM in finance.

Baseline closed macroeconomic ABM. Showed that simple agent-based models with decentralized markets can reproduce key macroeconomic regularities without top-down calibration.

Mark-0 ABM — a minimal agent-based macroeconomic model with rich phase diagrams. Showed how simple agent interactions produce qualitatively different economic regimes (growth, crisis, stagflation).

Green economic complexity — mapping countries' green industrial capabilities using product space methods. Interpreting economic complexity through the lens of green transition.

Technology improvement rates and Wright's Law. Empirical foundations of technology forecasting. Production network models connecting micro technology learning to macro productivity.

Statistical mechanics approaches to housing markets. Random utility models and their phase transitions. Bridging econophysics and agent-based complexity economics.

Supply chain contagion models during COVID-19. Production network ABMs for pandemic economic impact. Showed how supply chain disruptions cascade through production networks.

Empirical technology forecasting. Statistical testing of Wright's Law and Moore's Law across hundreds of technologies. Making technology cost prediction rigorous and probabilistic.

The "fast green transition is cheaper" paper (2022) — used technology forecasting to show that a rapid clean energy transition would likely save trillions vs. a slow transition. Major policy impact.

Creator of NetLogo — the most widely used platform for agent-based modeling. Democratized ABM for economics, ecology, and social science through accessible software.

Fat tails, antifragility, and Black Swan theory. Argued that standard economic models catastrophically underestimate tail risk. Influenced complexity thinking about non-Gaussian distributions in finance.

Social interactions and speculative bubbles through heterogeneous beliefs. Showed how interacting agents with disagreement generate bubbles and excess volatility. Bridging mainstream finance with complexity.

Co-creator of the small-world network model with Duncan Watts. Nonlinear dynamics and synchronization. "Sync" and "Nonlinear Dynamics and Chaos" — foundational math underlying complexity economics.

Evolutionary game theory applied to economic segregation, stereotypes, and inequality. Connecting complexity and agent-based reasoning to social and criminal justice outcomes.

Stochastic evolutionary game theory applied to economic conventions and norms. How institutions and conventions emerge from decentralized interactions. Innovation diffusion in networks.