A simulation-based optimization model that balances tourism revenue against environmental impact, using Juneau, Alaska as its primary case study and New Zealand as a second test. A per-visitor tax, and how its revenue is split across infrastructure, community programs, and conservation, is tuned to maximize a single Environmental-Economic (E) index.
Built with Python, NumPy, and Matplotlib.
For the full mathematical write-up, see the paper here.
Juneau, Alaska, a city of about 30,000 residents, set a record in 2023 with 1.6 million cruise passengers, hosting as many as seven large cruise ships and up to ~20,000 visitors on the busiest days. Those tourists bring in roughly $375 million and account for around 85% of all direct spending in the city, but they also bring overcrowding, strained drinking water and waste infrastructure, rising housing costs, and a growing carbon footprint. Around 22% of households report being negatively impacted by tourism, and the Mendenhall Glacier, one of Juneau's premier attractions, has receded the equivalent of eight football fields since 2007 as warming accelerates, leaving locals worried the tourists, and their revenue, will eventually disappear with the glacier.
This creates a genuine optimization problem. Caps, visitor fees, and higher taxes can protect natural and cultural resources, but residents who depend on tourism fear those same measures will drive visitors away and shrink their businesses. This project models that tension directly: it simulates how visitors respond to a tax, how the resulting revenue (reinvested into infrastructure, community programs, and conservation) feeds back into visitor capacity, carbon footprint, and revenue over a multi-year horizon, and it searches for the policy that best balances a healthy economy against a healthy environment so a tourist council can plan for a sustainable future.
Install the required package:
py -3 -m pip install numpyRun the simulation:
py -3 Model.pyEdit the decision variables at the top of Model.py to test a policy: the per-visitor tax Visitor_Tax and the spending shares Infrastructure_Share and Programs_Share. Running the script prints the final Environmental-Economic, carbon, and revenue scores along with the ending visitor count and capacity.
Three headline cases from a 25-year simulation of Juneau:
- Base case (no tax): revenue and E score each decline by ~0.01 and annual visitors fall by ~15,000, a slow erosion of both trade and environmental quality.
- Realistic case (Hawaii-style ~$50 tax, even split): E ≈ 1.27, with the carbon score rising ~0.6, much better for the environment at a modest cost to revenue.
- Best case (brute-force search): a $100 tax split 65% infrastructure / 10% programs / 25% conservation yields E ≈ 1.26 with both visitors and visitor capacity rising substantially over the period, the strongest balance of revenue and environmental health.