The Lotka-Volterra model assignment

14 - 23 July, Semkovo, Rila Mountain

The Lotka-Volterra model assignment

The Lotka-Volterra model, originally devised to describe the dynamics of biological systems in which two species interact, has found intriguing applications in the field of economics. Recent research trends have utilized this model to investigate various economic phenomena, highlighting its versatility and effectiveness in capturing complex interactions.

One such application is in the study of trade relationships. In a paper titled “The Evolution of Trade Relations between China and ASEAN Countries: An Analysis Based on the Lotka-Volterra Model” by Zhang and Wang (2023), the authors employ the model to analyze the trade dynamics between China and the ten ASEAN countries. The study identifies different types of trade relationships, such as competitive, trade-biased, and mutually beneficial, and provides insights into potential trade frictions and strategies for coordinated regional economic development.

Another innovative application of the Lotka-Volterra model is in the exploration of sustainable economic development. In their paper “Sustainable Development of the Global Economy: A Lotka-Volterra Ecosystem Model”, Zhang and Wang (2023) propose viewing the global economy as an ecosystem, with countries as species. The model is used to analyze the interactions between countries in terms of economic development, considering factors such as resource consumption, environmental pollution, and technological progress. The authors suggest that sustainable development can be achieved through the balance and coordination of these factors.

A third application is in the study of public concerns and their interactions. In “A Lotka-Volterra Based Approach to Modelling the Interaction among People’s Worries” by Dominioni, Sitas, and Tavoni (2023), the authors use the model to examine how different sources of concern, such as the environment, economy, safety, social issues, and immigration, interact in people’s minds. The study reveals that an increase in concern for the environment often promotes concerns for the economy, while an increase in economic concerns often reduces environmental concerns. This research provides valuable insights into public opinion dynamics and their implications for policy-making.

These recent applications of the Lotka-Volterra model in economics demonstrate its potential in capturing the complex dynamics of economic systems and providing valuable insights for policy-making. The model’s ability to describe interactions and dynamics makes it a powerful tool for economic analysis, and it is likely to see continued use and development in the future.

’’’ def lotka_volterra(x, y, a, b, c, d, dt): dx_dt = a * x - b * x * y dy_dt = c * x * y - d * y x += dx_dt * dt y += dy_dt * dt return x, y ‘’’

’’’ def simulate_lotka_volterra(x0, y0, a, b, c, d, dt, steps): x_values = [x0] y_values = [y0]

x = x0
y = y0
for _ in range(steps):
    x, y = lotka_volterra(x, y, a, b, c, d, dt)
    x_values.append(x)
    y_values.append(y)

return x_values, y_values '''

’’’

Set the model parameters

a = 1.2 b = 0.4 c = 0.6 d = 0.8 dt = 0.01 steps = 1000

Set the initial population sizes

x0 = 10 # Initial prey population size y0 = 5 # Initial predator population size

Simulate the Lotka-Volterra model

x_values, y_values = simulate_lotka_volterra(x0, y0, a, b, c, d, dt, steps)

Print the results

time = [i * dt for i in range(steps + 1)] for t, x, y in zip(time, x_values, y_values): print(f”Time: {t:.2f} Prey: {x:.2f} Predator: {y:.2f}”) ‘’’

x and y: These represent the populations of prey and predators, respectively, at a given time.
a: The growth rate of the prey population. It determines how fast the prey population grows in the absence of predators.
b: The predation rate. It determines the effect of predators on the prey population. A higher b value indicates that predators consume more prey, resulting in a decrease in the prey population.
c: The efficiency of converting consumed prey into predator offspring. It represents how effectively predators can utilize the prey as a source of energy and reproduction.
d: The mortality rate of predators. It determines how quickly predators die in the absence of prey.
dt: The time step or interval at which the simulation progresses. It controls the granularity of the simulation.
steps: The number of simulation steps or iterations to perform.
By adjusting these parameters, you can explore different scenarios and understand the dynamics between the prey and predator populations. For example, increasing the prey growth rate (a) or reducing the predation rate (b) could lead to an increase in the prey population and, subsequently, an increase in the predator population. On the other hand, increasing the predation rate or reducing the conversion efficiency (c) might cause the predator population to increase while the prey population declines.

It’s important to note that the Lotka-Volterra model is a simplified representation of real ecological systems and makes several assumptions, such as constant parameter values, no external factors impacting the populations, and a homogeneous environment. Nevertheless, it serves as a useful conceptual framework for studying predator-prey interactions and population dynamics.

Certainly! One economic simulation that can be analyzed using the Lotka-Volterra model is the relationship between producers and consumers in a market. In this scenario, the prey population can represent the number of consumers, while the predator population can represent the number of producers.

Let’s define the parameters in the context of this economic simulation:

x: Number of consumers or buyers in the market.
y: Number of producers or sellers in the market.
a: Consumer growth rate. It represents the rate at which new consumers enter the market, such as through population growth or increasing demand. b: Producer competition rate. It indicates how the number of producers affects the consumer population. More producers might lead to increased competition for consumers, resulting in a decrease in the consumer population.
c: Producer success rate. It represents how well producers can attract and retain consumers. A higher c value implies that producers are more successful in satisfying consumer demand and gaining market share.
d: Consumer attrition rate. It represents the rate at which consumers leave the market due to factors such as changing preferences, economic conditions, or dissatisfaction.
dt: The time step or interval at which the simulation progresses. It controls the granularity of the simulation. steps: The number of simulation steps or iterations to perform.
By running the simulation with different parameter values, you can analyze the dynamics between consumers and producers in the market. For example, increasing the consumer growth rate (a) might lead to a higher consumer population, which can attract more producers. However, if the producer competition rate (b) is also high, it could result in a decline in the consumer population due to increased competition. On the other hand, if the producer success rate (c) is high, producers may effectively attract and retain consumers, leading to a stable or growing consumer population.

This economic simulation based on the Lotka-Volterra model provides a simplified representation of market dynamics and can be used to gain insights into the interplay between consumers and producers, competition, market growth, and attrition.

Here are some resources where you might find economic data analyzed through the Lotka-Volterra model:
1. An Economic Application of the Lotka-Volterra Predator-Prey Model: This paper presents Goodwin’s original model, an augmented Goodwin model, and empirical tests.
2. An Economic Application of the Lotka-Volterra Predator-Prey Model: This document also discusses the application of the Lotka-Volterra model in economics.
3. The Lotka-Volterra Equations in Economics: An Italian Precursor: This paper on ResearchGate discusses the introduction of the Lotka-Volterra equations into economics.
4. Lotka-Volterra equations, diagram 2: This page on ResearchGate provides a diagram of the Lotka-Volterra equations in economics.
5. Data-Driven Corrections of Partial Lotka–Volterra Models: This paper presents a data-driven “closure model” for partial Lotka–Volterra equations.
Please note that while these resources discuss the application of the Lotka-Volterra model in economics, they may not provide direct download links for the analyzed data. You might need to contact the authors or the hosting institutions for access to the raw data.