Simulation Model

A computer simulation model has been published in the International Journal of Community Currency Research that illustrates token-dollar flow in a virtual US county. A press release has been issued that announces publication of the paper.

The aims of the paper are to: (1) introduce the LEDDA framework and Token Exchange System (which governs dollar and token flow); (2) describe some general concepts of token-dollar flow; and (3) demonstrate that a stock-flow consistent illustrative model of token and dollar flow can be parameterized such that every LEDDA-member family receives a direct income gain over baseline in every year, and the membership eventually achieves full income equality and full employment. Results presented in the model are for a county population of size 100,000 adults.

The model illustrates a token-dollar economy, and is not predictive. While hypothetical, it is semi-realistic in the sense that dollar flows at the start of the simulation resemble those of a real county economy, and conditions evolve from this base. For example, starting income levels resemble real income levels, and tax rates resemble real tax rates.

Although the model is elementary in many respects, it represents a milestone; it is the first agent-based simulation model to examine semi-realistic flows of complementary and national currency within a local economy. It sets the stage for future studies that will expand the model, assess its assumptions, and examine whether such results can be practically achieved in a real LEDDA.

Links to the paper and it’s appendix can also be found at A collection of graphs produced by the model is also available.

Paper Title and Abstract

Boik J. “First microsimulation model of a LEDDA community currency-dollar economy.” International Journal of Community Currency Research. 2014; 18(A), 11-29.

Results are presented for a first-in-class microsimulation model of a local-national currency system. The agent-based, stock-flow consistent model uses US Census income data as a starting point to project the evolution of local currency (community currency) and dollar flows within a simplified county-level economy over a period of 28 years. Changes in the distribution of family income are tracked. The community currency system under investigation is the Token Exchange System (TES), a component of the larger Local Economic Direct Democracy Association (LEDDA) framework under development by the Principled Societies Project. The model captures key design features of a TES, and results suggest parameter ranges under which the simulated TES is capable of achieving stated aims. Median and mean take-home family incomes more than double during the simulation period, income inequality is nearly eliminated, and the unemployment rate drops to a 1 percent structural level. The need for more sophisticated modeling of a TES, and avenues for future research, are discussed.

Python TES-simulation Package

The Python package TES-simulation runs the simulation model described in the paper. The package can be downloaded at  See the installation instructions on the Pypi page. The package was developed and tested using a Linux operating system. It has not been tested on Windows operating systems.

The package is released to the public under a GPL version 3 license.


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