## Browse quantitative models header

There follows a list of quantitative models in the SES Library.

There follows a list of quantitative models in the SES Library.

Title | Type |
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## Life table | Model |

The life table model is one of the type of survival analysis which pertains to "time to event". The information that were accumulated throughout the study is one of the advatage of this method.This often used in demographics and epidemiology but can also be used on agricultural economics. Sperling and Loevinsohn (1992) used this method in analyzing varietal diffusion for beans in which the main objective is to know howm nay technology adopters remains after a time period. | 30 Nov 2017 |

## Leukopoiesis Model | Model |

# Eqn 1:#β(Q) is the introduction rate#β0 represents the maximal rate of introduction in the proliferating phase#θ1 is the value for which β reaches half of its maximal value#n is the sen- sitivity of the rate of reintroduction#Q is the quiscent cells# Eqn 2:#k(W) is the differentiation rate#k0 is a proportionality coefficiet#m and θ2 depend on the growth factors responsible for maturation of considered white blood cells#W is lymphocytes (T, B, or NK)# Eqn 3:#Kv is the differentiation rate to... | 03 Oct 2016 |

## Human and nature dynamics (HANDY): Modeling inequality and use of resources in the collapse or sustainability of societies | Model |

HANDY is a 4-variable thought-experiment model for interaction of humans and nature. The focus is on predicting long-term behavior rather than short-term forecasting. Carrying Capacity is developed as a practical measure for forecasting collapses. A sustainable steady state is shown to be possible in different types of societies but over-exploitation of either Labor or Nature results in a societal collapse. | 09 Oct 2016 |

## Fractal Poverty Traps | Model |

The dynamic model for poverty traps contains parameters as government policies and technologies, and variables such as income, expenditures, assets holdings and anthropometric status. This dynamic model for poverty traps offers a new perspective by showing the existence of multiple stable equilibria, which implies that there's one unstable dynamic equilibria. At this unstable equilibria, any little shock in the system will cause a switch to state equilibrium. Different to the standard economic... | 29 Nov 2017 |

## Fishery Model | Model |

This is a standard Gordon-Schaefer model that simulates a simple open-access fishery in discrete time. A fishery stock grows logistically and is harvested by humans. Fishers always exert too much effort and harvest fish at a level that is socially NOT optimal. This happens because fishers are driven to harvest until their net profit drops down to zero. A socially optimal level of harvesting effort is attained when marginal cost of harvesting effort and marginal revenue from harvesting become... | 09 Aug 2016 |

## Effects of population and population pressure on forest resources and their conservation: a modeling study | Model |

in this model, cumulative density of forest resources and population density use generalized logistic models with predatory-prey type nonlinear interactions. The model is an effort to capture not only the effect of population density on forest resources (a logistic model), but also the effect of population pressure on forest resources, which grows proportionally to population density and is limited by the carrying capacity of the forest. Additionally, it models the effect of economic... | 01 Oct 2016 |

## Effect of infrastructure design on commons dilemmas | Model |

The authors address the question of how infrastructure design affects SES sustainability in two stages. First, they explore the effects of design variations in shared infrastructure on long-term system behavior in a model system. They examine two types of distribution infrastructure, one with and one without upstream−downstream asymmetry, and different threshold characteristics of infrastructure maintenance. Second, they evaluate how these design variations influence the robustness of... | 09 Oct 2016 |

## Ecological-economic model for optimal control of fire-driven, semi-arid rangelands | Model |

This is an ecological-economic model that endogenizes discontinuous change between states of fire-driven, semi-arid rangelands which may exist in varying degrees as grassland and woodlands depending partly on the given soil conditions. More sandy soils will result in woodlands, whereas clay soils will more likely result in grasslands. One of the critical features of this model is the existence and impact of fires on these different types of rangelands. Grasslands may build up biomass and create... | 01 Oct 2016 |

## Dynamics of coupled populations in an open, three-trophic-level system | Model |

This model explicitly incorporates the immigration and emigration processes in the context of three-trophic-level systems (e.g., a stream reach), and reveals how the coupled populations will change in response to the primary-productivity gradients (e.g., r, K). In contrast, traditional simple food-chain models study mostly two-trophic-level system which can be open or close. More interstingly, though not reflected here, there are two contrasting models presented in the paper:... | 09 Oct 2016 |

## Demographic-Fiscal Model of the Growth and Collapse of Agrarian States | Model |

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## Culture and Human Agro-ecosystem Dynamics: the Tsembaga of New Guinea | Model |

The model of Tsembaga agro-ecology explores the coupled dynamics involving population growth, renewable resource base, resource consumption by humans, and the self-regulating effect of cultural ritual. The model demonstrates that the cultural ritual of Tsembaga (Kaiko) can stabilize the Tsembaga population and its resource level. This is achieved by attenuating wildly fluctuating limit cycles of population and resource levels down to desirable small-amplitude cycles. Anderies (1998) describes... | 09 Aug 2016 |

## Conflict between groups of players in coupled socio-economic and ecological dynamics | Model |

This is a model for the coupled dynamics of conflict between two different user groups regarding their socioeconomic choice (between cooperative and non-cooperative collective action) and nutrient loading input level into a lake water system. Suzuki and Iwasa (2009),gives the following overview of the model. "Conflict among multiple groups is a major source of difficulty in environmental conservation. People are often divided into various groups that have different social factors, sometimes ... | 09 Aug 2016 |

## Brander-Taylor Model | Model |

This is the original Brander-Taylor Easter Island model. Brander and Taylor (1998) describes the model as the following: "The paper presents a general equilibrium model of renewable resource and population dynamics related to the Lotka-Volterra predator-prey model, with man as the predator and the resource base as the prey. We apply the model to the rise and fall of Easter Island, showing that plausible parameter values generate a 'feast and famine" pattern of cyclical adjustment in... | 09 Aug 2016 |

## Australian Rangelands Model | Model |

This model tells a story of resilience of a rangeland system in Australia. Anderies et al. (2002) provides the following overview of the model. "We developed a stylized mathematical model to explore the effects of physical, ecological, and economic factors on the resilience of a managed fire-driven rangeland system. Depending on grazing pressure, the model exhibits one of three distinct configurations: a fire-dominated, grazing-dominated, or shrub-dominated rangeland system. Transaction costs... | 09 Aug 2016 |

## Animated demonstration of the Lorenz Model | Model |

Animated demonstration of the Lorenz model and its sensitivity to initial conditions. The simulation starts with twenty points very close to each other, and follows them as they move further away. The starting values differ in the fifth and sixth significant digits of a single coordinate. The Lorenz model was developed by Edward Lorenz in 1963 to study fluid mechanics.The model is a three-dimentional system of differential equations. Specifically, the model describes the convection motion of a... | 09 Aug 2016 |