Abstract:

This presentation details an economic valuation study of the Puentes Sopó ecotourism park, utilizing a simplified zonal travel cost method (TCM). The study aims to estimate the recreational value of the park by determining the consumer surplus visitors obtain. It outlines the historical context and methodology of TCM, including data collection via surveys for origin, costs, and socioeconomic factors. The core analysis involves calculating travel costs (displacement, time opportunity, entrance fee) from four defined zones, estimating visitor demand based on varying entrance prices, and computing the consumer surplus using a geometric approximation of the demand curve. Additionally, the study calculates a break-even point for a proposed new trail and applies the Poisson distribution to model daily visitor probabilities.

Summary: Economic Valuation of Puentes Sopó Ecotourism Park

• 0:02 Project Introduction: The study focuses on the economic valuation of the Puentes Sopó ecotourism park using the travel cost method.
• 0:18 Travel Cost Method (TCM) Overview: TCM, a revealed preference method, originated post-WWII to value U.S. National Parks. It observes that park visits decrease with increased travel distance and cost, allowing for the estimation of a demand function and, subsequently, consumer surplus.
• 1:08 Methodological Evolution: Initially a zonal method (applied in Yosemite in the late 1950s), it evolved with regression analysis in the 1960s-70s, leading to individual-based estimations.
• 1:32 Core Principle: TCM measures the "excedent" (consumer surplus) visitors obtain, not the travel cost itself, which represents the welfare gained from the recreational experience.
• 2:12 Data Collection: Information was gathered through surveys, capturing visitor origin, economic costs, opportunity costs of time, socioeconomic characteristics, and environmental quality perceptions.
• 2:43 Zonal Definition: Four zones were defined for the zonal TCM: Cajicá (~7 km), Sopó (~10.4 km), Chía (~12.9 km), and Zipaquirá (~21.8 km). The methodology is considered applicable only up to 60 km due to topographic limitations.
• 3:17 Travel Cost Components:
  • Displacement Cost: Calculated based on gasoline consumption (1L/12km), gasoline price ($2,563 COP/L), and distance, yielding $213 COP/km. For a car shared by four people, each pays a quarter of the gasoline cost.
  • Time Cost: Derived from the minimum legal monthly wage, calculating a per-minute value multiplied by round-trip travel time.
  • Entrance Fee: A fixed fee of $10,000 COP, set by the regional autonomous corporation (CAR).
• 4:57 Sample Size & Visitation: Based on 955 weekly weekend visits to Puentes Sopó, a sample size of 127 visitors was determined for a 95% confidence level. Hotelling's method was applied to show visit trends: fewer visits from the closest zone (Cajicá), increasing for intermediate zones, and decreasing again for the farthest (Zipaquirá) due to higher costs.
• 6:09 Visitor Ratios: The percentage of visits per inhabitant was calculated for each zone using municipal census data.
• 6:34 Demand Curve & Price Increment: An incremental entrance price strategy was modeled (starting with zero increase), where subsequent increases were based on travel cost differences between zones, augmented by stated willingness-to-pay from the surveys.
• 7:32 Estimated Visits: As the entrance price increased, estimated visits from more distant zones decreased, eventually concentrating only on closer zones, and finally resulting in no visits at the highest price increment.
• 9:27 Demand Curve Visualization: A demand curve was plotted showing estimated visits (x-axis) against the entrance price increment (y-axis).
• 9:51 Consumer Surplus Calculation: The area under the demand curve was calculated using a geometric method (summing areas of triangles and rectangles).
• 11:57 Consumer Surplus Result: The total calculated area was $438,003 COP. Dividing by the 127 surveyed individuals yielded an average consumer surplus of $3,448 COP per person, interpreted as the welfare gained by each visitor.
• 13:05 Simplified Methodology: The study acknowledges using a simplified zonal method with only four zones; a more complex analysis with more zones would typically require regression.
• 13:38 Break-Even Analysis for New Trail: For a proposed new trail, using the $3,448 COP consumer surplus per person as the unit price, and considering fixed costs for maintenance and salary, the break-even point was determined to be 960 visitors, grouped into 38 groups of 25.
• 14:17 Poisson Distribution Introduction: The Poisson distribution, a discrete probability distribution, was used to model the number of occurrences (visits) within a defined interval (e.g., a day), with the formula P(X=k) = (λ^k * e^-λ) / k!.
• 15:48 Poisson Application to Visitor Data:
  • An average of 136 persons per day was used (based on 955 weekly visits).
  • The probability of 60 visits in a day was stated as 10.9%.
  • The probability of 200 visits in a day was stated as 34.17%.
  • It was concluded that 200 visits in a day are more probable than 60 visits.

Analyze and Adopt

Domain: Environmental Economics & Quantitative Analysis Persona: Senior Resource Economist / Quantitative Policy Analyst Tone: Academic, technical, and analytical. Focus is on methodology, welfare measurement, and statistical rigor.

Abstract

This presentation outlines an economic valuation study of the Ecotourist Park "Puente Sopó," utilizing the Travel Cost Method (TCM) to estimate the recreational value of a non-market environmental asset. The methodology relies on revealed preference theory, mapping visitor origins to calculate costs associated with travel, time opportunity, and entry fees. By establishing a zonal demand curve and calculating the area under said curve, the researchers estimate the Consumer Surplus as a proxy for the park's total economic welfare. Additionally, the study applies the Poisson Distribution to model visitor arrival probabilities, providing a quantitative basis for operational capacity planning and infrastructure investment, specifically regarding the maintenance of a proposed new trail.

Summary: Travel Cost Valuation and Capacity Modeling

• 0:18 Theoretical Framework: The Travel Cost Method (TCM) is grounded in revealed preference theory. It assumes an inverse relationship between distance/cost and the frequency of visits, allowing for the construction of a demand function.
• 0:59 Zonal TCM Methodology: The study partitions the catchment area into four zones (7km, 10.4km, 12.9km, and 21.8km) to analyze demand variability. The method is restricted to a 60km radius to maintain topographical consistency.
• 3:25 Cost Composition: The "Total Travel Cost" is calculated as a summation of three variables:
  • Direct Transport: Fuel efficiency (12km/liter) and local gasoline prices.
  • Opportunity Cost of Time: Derived from the legal minimum wage per minute.
  • Access Fee: The fixed entry cost (10,000 COP) set by the management authority.
• 5:06 Sample & Population: Using a 95% confidence level, a sample size of 127 visitors was determined from a weekend population of 955.
• 9:51 Consumer Surplus Calculation: By applying a geometric approach to the demand curve (summing the areas of triangles and rectangles derived from travel increments), the researchers estimated a Consumer Surplus of 3,448 COP per visitor, representing the individual welfare gain from the park's services.
• 13:46 Break-even Point: To justify the capital expenditure of a new trail, the study calculates a break-even requirement of 960 visitors, organized into 38 groups of 25, to cover fixed maintenance costs.
• 14:24 Poisson Distribution Analysis: To predict operational load, the Poisson model was applied to daily visitor arrivals (mean $\mu = 136$):
  • 16:49 Probability of 60 daily visits: ~1.9%
  • 17:20 Probability of 200 daily visits: ~34.17%
• 17:29 Takeaway: The model indicates that higher-volume days (200 visitors) are significantly more probable than lower-volume days (60 visitors) under the current distribution parameters.

Expert Recommendation for Peer Review: To ensure the integrity of this study, I recommend review by: 1. Environmental Economists: To validate the choice of the Zonal TCM over the Individual TCM and verify the treatment of travel time opportunity costs. 2. Statisticians/Operations Researchers: To verify the Poisson model's assumption of stationarity (i.e., whether visitor arrival rates are truly independent and constant over the time intervals used). 3. Park Management Specialists: To assess the practical application of the calculated break-even visitor threshold relative to the physical carrying capacity of the site.