10 papers
Treatment Effects with Correlated Spillovers: Bridging Discrete and Continuous Methods
Tatsuru Kikuchi
This paper develops a continuous functional framework for treatment effects propagating through geographic space and economic networks. We derive a master equation from three indep…
Emergent Dynamical Spatial Boundaries in Emergency Medical Services: A Navier-Stokes Framework from First Principles
Tatsuru Kikuchi
Emergency medical services (EMS) response times are critical determinants of patient survival, yet existing approaches to spatial coverage analysis rely on discrete distance buffer…
Dynamic Spatial Treatment Effects as Continuous Functionals: Theory and Evidence from Healthcare Access
Tatsuru Kikuchi
I develop a continuous functional framework for spatial treatment effects grounded in Navier-Stokes partial differential equations. Rather than discrete treatment parameters, the f…
Dynamic Spatial Treatment Effect Boundaries: A Continuous Functional Framework from Navier-Stokes Equations
Tatsuru Kikuchi
I develop a comprehensive theoretical framework for dynamic spatial treatment effect boundaries using continuous functional definitions grounded in Navier-Stokes partial differenti…
Nonparametric Identification of Spatial Treatment Effect Boundaries: Evidence from Bank Branch Consolidation
Tatsuru Kikuchi
I develop a nonparametric framework for identifying spatial boundaries of treatment effects without imposing parametric functional form restrictions. The method employs local linea…
Nonparametric Identification and Estimation of Spatial Treatment Effect Boundaries: Evidence from 42 Million Pollution Observations
Tatsuru Kikuchi
This paper develops a nonparametric framework for identifying and estimating spatial boundaries of treatment effects in settings with geographic spillovers. While atmospheric dispe…
Spatial and Temporal Boundaries in Difference-in-Differences: A Framework from Navier-Stokes Equation
Tatsuru Kikuchi
This paper develops a unified framework for identifying spatial and temporal boundaries of treatment effects in difference-in-differences designs. Starting from fundamental fluid d…
A Unified Framework for Spatial and Temporal Treatment Effect Boundaries: Theory and Identification
Tatsuru Kikuchi
This paper develops a unified theoretical framework for detecting and estimating boundaries in treatment effects across both spatial and temporal dimensions. We formalize the conce…
Stochastic Boundaries in Spatial General Equilibrium: A Diffusion-Based Approach to Causal Inference with Spillover Effects
Tatsuru Kikuchi
This paper introduces a novel framework for causal inference in spatial economics that explicitly models the stochastic transition from partial to general equilibrium effects. We d…
Methods of Stochastic Field Theory in Non-Equilibrium Systems -- Spontaneous Symmetry Breaking of Ergodicity
Tatsuru Kikuchi
Recently, a couple of investigations related to symmetry breaking phenomena, 'spontaneous stochasticity' and 'ergodicity breaking' have led to significant impacts in a variety of f…