Computational Model Library

Displaying 10 of 179 results for "Mark R Kramer" clear search

Agent-based model of power dynamics in agri-food systems

Tim Williams | Published Sunday, October 27, 2024 | Last modified Thursday, June 12, 2025

This is a stylised agent-based model designed to explore the conditions that lead to lock-ins and transitions in agri-food systems.

The model represents interactions between four different types of agents: farmers, consumers, markets, and the state. Farmers and consumers are heterogeneous, and at each time step decide whether to trade with one of two market agents: the conventional or alternative. The state agent provides subsidies to the farmers at each time step.

The key emergent outcome is the fraction of trade in each time step that flows through the alternative market agent. This arises from the distributed decisions of farmer and consumer agents. A “sustainability transition” is defined as a shift in the dominant practices (and associated balance of power) towards the alternative paradigm.

This paper investigates the impact of agents' trading decisions on market liquidity and transactional efficiency in markets for illiquid (hard-to-trade) assets. Drawing on a unique order book dataset from the fine wine exchange Liv-ex, we offer novel insights into liquidity dynamics in illiquid markets. Using an agent-based framework, we assess the adequacy of conventional liquidity measures in capturing market liquidity and transactional efficiency. Our main findings reveal that conventional liquidity measures, such as the number of bids, asks, new bids and new asks, may not accurately represent overall transactional efficiency. Instead, volume (measured by the number of trades) and relative spread measures may be more appropriate indicators of liquidity within the context of illiquid markets. Furthermore, our simulations demonstrate that a greater number of traders participating in the market correlates with an increased efficiency in trade execution, while wider trader-set margins may decrease the transactional efficiency. Interestingly, the trading period of the agents appears to have a significant impact on trade execution. This suggests that granting market participants additional time for trading (for example, through the support of automated trading systems) can enhance transactional efficiency within illiquid markets. These insights offer practical implications for market participants and policymakers aiming to optimise market functioning and liquidity.

ACT: Agent-based model of Critical Transitions

Igor Nikolic Oscar Kraan Steven Dalderop Gert Jan Kramer | Published Wednesday, October 18, 2017 | Last modified Monday, August 27, 2018

ACT is an ABM based on an existing conceptualisation of the concept of critical transitions applied to the energy transition. With the model we departed from the mean-field approach simulated relevant actor behaviour in the energy transition.

Peer reviewed Simulating the Economic Impact of Boko Haram on a Cameroonian Floodplain

Mark Moritz Nathaniel Henry Sarah Laborde | Published Saturday, October 22, 2016 | Last modified Wednesday, June 07, 2017

This model examines the potential impact of market collapse on the economy and demography of fishing households in the Logone Floodplain, Cameroon.

Informal risk-sharing cooperatives : ORP and Learning

Juliette Rouchier Victorien Barbet Renaud Bourlès | Published Monday, February 13, 2017 | Last modified Tuesday, May 16, 2023

The model studies the dynamics of risk-sharing cooperatives among heterogeneous farmers. Based on their knowledge on their risk exposure and the performance of the cooperative farmers choose whether or not to remain in the risk-sharing agreement.

WATER REUSE ADOPTION BY FARMERS (WRAF)

Farshid Shoushtarian | Published Tuesday, September 27, 2022

Agriculture is the largest water-consuming sector worldwide, responsible for almost 70% of the world’s total freshwater consumption. Agricultural water reuse is one of the most sustainable and reliable methods to alleviate water shortages worldwide. However, the dynamics of agricultural water reuse adoption by farmers and its impacts on local water resources are still unknown to the scientific community, according to the literature. Therefore, the primary purpose of the WRAF model is to investigate the micro-level dynamics of agricultural water reuse adoption by farmers and its impacts on local water resources. The WRAF was developed using agent-based modeling as an exploratory tool for scenario analysis. The model was specifically designed for researchers and water resources decision-makers, especially those interested in natural resources management and water reuse.
WRAF simulates a virtual agricultural area in which several autonomous farms operate. It also simulates these farms’ water consumption dynamics. The developed model includes two types of agents: farmers and wastewater treatment plants. In general, farmer agents are the main water-consuming agents, and wastewater treatment plant agents are recycled water providers in the WRAF model. Dynamic simulation of agricultural water supply and demand in the area allows the user to observe the results of various irrigation water management scenarios, including recycled water. The models also enable the user to apply multiple climate change scenarios, including normal, moderate drought, severe drought, and wet weather conditions.

FNNR-ABM

Judy Mak | Published Thursday, February 28, 2019 | Last modified Saturday, December 07, 2019

FNNR-ABM is an agent-based model that simulates human activity, Guizhou snub-nosed monkey movement, and GTGP-enrolled land parcel conversion in the Fanjingshan National Nature Reserve in Guizhou, China.

Quick-start guide:
1. Install Python and set environmental path variables.
2. Install the mesa, matplotlib (optional), and pyshp (optional) Python libraries.
3. Configure fnnr_config_file.py.

Peer reviewed Family Herd Demography

Mark Moritz Ian M Hamilton Andrew Yoak Rebecca Garabed Abigail Buffington | Published Monday, August 15, 2016 | Last modified Saturday, January 06, 2018

The model examines the dynamics of herd growth in African pastoral systems. We used it to examine the role of scale (herd size) stochasticity (in mortality, fertility, and offtake) on herd growth.

Informal Information Transmission Networks among Medieval Genoese Investors

Christopher Frantz | Published Wednesday, October 09, 2013 | Last modified Thursday, October 24, 2013

This model represents informal information transmission networks among medieval Genoese investors used to inform each other about cheating merchants they employed as part of long-distance trade operations.

This model allows for analyzing the most efficient levers for enhancing the use of recycled construction materials, and the role of empirically based decision parameters.

Displaying 10 of 179 results for "Mark R Kramer" clear search

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