Department of Urban Planning and Public Policy · UC Irvine

We study the spatial organization of neighborhoods, cities, and regions.

Spatial methods for urban processes, open science for public decisions.

SSUS is the research lab of Elijah Knaap at the University of California, Irvine. We draw on urban economics, sociology, and geography to explain why activity concentrates where it does, how places change, and who gains or loses as they do.

People and places are connected and interdependent. Understanding network structure and relationships embedded in space requires formal geographic models: we develop spatial econometric and Bayesian models of spillovers, sorting, and flows, and the sparse numerical tools that make them feasible for whole metropolitan regions.

Research areas

Structure and Form

How land, housing, and jobs are arranged across a region.

  • Land and housing markets
  • Economic geography
  • Agglomeration
  • Urban form

Sorting and Change

Who lives where, and how neighborhoods change.

  • Residential sorting
  • Segregation
  • Neighborhood change
  • Neighborhood effects

Access and Policy

Who can reach what, and how public decisions change it.

  • Access to opportunity
  • Schools
  • Public health
  • Transportation
  • Fair housing

How We Work

  • Spatial econometrics
  • Spatial statistics
  • Bayesian estimation at scale
  • Discrete choice models
  • Measurement models
  • Areal interpolation
  • Regionalization
  • Network accessibility
  • Open-source software
Nine small line charts, one per metropolitan area, each showing a segregation index falling as the distance defining the neighborhood grows, with one line per census year from 1980 to 2010.

From the work

Segregation depends on the scale you measure it at

A multiscalar profile recomputes segregation as the neighborhood around each location widens. Here, nine U.S. metropolitan areas from 1980 to 2010: the curves fall with distance, and the shape of the fall differs from one metro to the next.

The segregation package computes these profiles

The book

Urban Analysis & Spatial Science

Theory, Methods, & Code for Studying Neighborhoods, Cities, & Regions

Knaap's textbook introduces the theory and intermediate quantitative methods of urban and regional analysis as a series of executable computational notebooks in Python. Each chapter takes a topic from the social science and policy literature and carries out a real analysis step by step.

CRC Press, forthcoming 2027 · draft online, CC BY-NC-ND

Read the draft
Bid-rent curves around a market centerThree bid-rent lines fall with distance from the market center. Commercial bids are highest and steepest and win out to distance a; residential bids win from a to b; agricultural bids, lowest and flattest, win from b to c. Land rent follows the upper envelope of the three lines.Land rentabcabcMarket centerCommercialResidentialAgriculture
Bid rent, from the book's part on urban spatial structure: each land use outbids the others over one band of distance from the market center, so land rent follows the upper envelope of the three bids.
  1. Spatial Data
  2. Interpolation and Change of Support
  3. Spatial Analysis
  4. Accessibility and Interaction
  5. Urban Spatial Structure
  6. Segregation
  7. Urban Factor Models
  8. Neighborhood Delineation
  9. Neighborhood Change
  10. Spatial Econometrics
  11. Location Models
  1. Upcoming

    PySAL workshop and new segregation research at NARSC, Philadelphia

    Knaap and Sergio Rey teach Spatial Data Analysis and Econometrics with PySAL on the first day of the North American Regional Science Council’s annual meeting, November 11–14, and Knaap presents Separated, Polarized, and Factioned?

  2. Release

    sparsax 0.11.0

    Sparse direct solvers for JAX, backed by SuiteSparse: factorizations, solves, and log-determinants that run natively inside compiled code.

  3. News

    Knaap joins the editorial board of Regional Science Policy & Practice

Projects

All projects

Selected publications

All publications
  1. 2026
    segregation: Segregation Analysis, Inference, and Decomposition in Python

    Renan X. Cortes, Elijah Knaap, Sergio J. Rey · Journal of Open Source Software

  2. 2025
    Exploring Space-Time Interactions in Fatal Opioid Overdoses

    Sergio J. Rey, Elijah Knaap, Alejandra Cabral, Jennifer Syvertsen · Geographical Analysis

  3. 2024
    Segregated by design? Street network topological structure and the measurement of urban segregation

    Elijah Knaap and Sergio J. Rey · Environment and Planning B: Urban Analytics and City Science

  4. 2024
    Measuring two decades of urban spatial structure: The evolution of agglomeration economies in American metros

    Elijah Knaap and Sergio J. Rey · Computers, Environment and Urban Systems

Software

All software