Every festival that takes public money gets the same question afterwards: what did the event do for the local economy? Funders want a number. Councils want a number. Most organizers end up with an attendance estimate, a short visitor survey, and a lot of hope.
This guide explains how event impact is usually estimated in Ontario, why the survey step so often breaks, and where mobile location data can help. It also covers what location data cannot do, so you know what you still need to collect yourself.
How event impact is normally estimated in Ontario
The three ingredients
Almost every festival impact estimate in Ontario is built from the same three pieces:
- How many people came. Ticket scans, gate counts, wristbands, or for open-access events, estimates from counting and sampling.
- How many of them were visitors. Only spending by people from outside the area counts as new money for the local economy. Spending by residents would mostly have happened anyway.
- How much the visitors spent. Usually from a survey asking about tickets, food, lodging, fuel and shopping.
Those inputs then go into an economic model that turns spending into jobs, GDP and tax figures.
TREIM, Ontario's model
In Ontario, the usual model is TREIM, the Tourism Regional Economic Impact Model run by the Ministry of Tourism, Culture and Gaming. It is an online tool with no user fees. You choose a geography and a year, then enter either visitor spending or visitor numbers, and it estimates the economic effects for the province and the local area 2.
TREIM uses the standard Canadian definition of a visitor: someone on an overnight trip, or a same-day trip of 40 km or more from home. Routine trips such as commuting and regular shopping do not count 2.
TREIM does the economics for you. It does not tell you how many of your attendees were visitors. You have to bring that.
One practical note: in November 2026, the ontario.ca TREIM page said the TREIM website was unavailable because of a technical issue 2. Check the page before you plan your report around it, and ask your program contact what to use if it is still down.
Sport Tourism Canada's models
For sport events, and for festivals through its FEST PRO service, Sport Tourism Canada offers paid studies that measure actual impact after the event. Its site describes data collected on site through face-to-face intercept surveys, kiosks and QR codes 5.
What funders ask you to report
Experience Ontario is the province's main festival and event funding program. Its 2026 guidelines are clear that tourism is the point. The program funds events with a tourism economic impact, and it defines a tourist much the same way TREIM defines a visitor: a person, including an Ontario resident, who travels 40 km or more one way, or crosses into Ontario, to attend 3.
A few details from the 2026 guidelines matter here:
- Tourist share is an eligibility test. For the Established Events stream, the event must show tourist attendance of at least 30%, or at least 5,000 tourists, at least once in the past three years. The Capacity Building stream does not carry this test 3.
- Final reports need evidence. Recipients report within 90 days of the event. They are expected to supply supporting evidence for their performance metrics, such as ticket sales reports, a headcount tracker or an on-site survey, plus any economic impact studies or visitor analysis 3.
- Impact studies are an eligible expense. The guidelines list economic impact studies among eligible costs 3.
So the funder needs two things you may not have: a defensible share of visitors who came from 40 km or more, and evidence behind it.
Why survey-based estimates often fall short
The sample of visitors is usually too small
Survey guidelines for open-access festivals, published in 2007 with Ontario's tourism ministry among the funders, recommend at least 200 completed surveys with non-local attendees before you estimate their economic impact. If you want separate results for, say, in-province and out-of-province visitors, you need 200 for each group 4. The document is now available only as an archived copy, and we found no newer provincial edition.
That bar is hard for a community festival to reach. Volunteers with clipboards or a QR code on a sign tend to collect replies from whoever is willing, and many of them live nearby. The same guidelines suggest that if fewer than 10% of attendees are tourists, organizers may want to measure on-site spending instead of tourism impact 4.
A documented example
In 2023, the McMaster Research Shop evaluated Hamilton's It's Your Festival for the Hamilton Folk Arts Heritage Council. The team ran after-event surveys of attendees and vendors. Because too few non-local visitors were in the sample, they could not assess economic impact. They measured the event's economic output from the spending of all attendees instead 1.
That is not a failing of the researchers. It is what happens when the survey is the only source of visitor origin. The one number the funding case depends on, the share of people from away, is the number the survey is least able to supply.
Open-access events are harder still
The 2007 guidelines are frank that counting people at an ungated event is complex and labour intensive. People come and go at different points, and passers-by mix with attendees. Even random interviews do not give a representative sample unless you also have a system for estimating total attendance 4. Downtown festivals, street events and parades sit squarely in this category.
Surveys also carry known biases
The same guidelines flag a few common errors. Local residents' spending must be left out of a tourism impact estimate. Visitors who would have come anyway, called "casuals", and "time switchers", who would have visited at another time, also need separate treatment 4. A survey can ask about these, but only of the people who answer it.
Where mobile location data helps
Privacy-compliant mobile location data comes from apps where people have opted in to location sharing. It is aggregated and anonymized, with no personal information, and it describes patterns across many devices, never individuals. Each device's home area is estimated at the six-digit postal code level 6. That last point is what makes it useful for event impact.
Here is what it can show.
Visitor origin shares
The share of event visitors who were local, regional, or from further away, measured by distance from their home area. This does not depend on who agrees to fill in a form, so out-of-town visitors who would never stop for a survey are still in the picture.
Event lift against ordinary weekends
How much traffic rose during the event compared with surrounding weekends, for the site and the area around it. This is a cleaner answer to "did the event bring people in?" than a headcount alone, because it compares the event with what a normal weekend looks like.
Day and time patterns
Which days and hours grew. This tells you whether a new Thursday program or a late-night stage changed behaviour.
Spread across the area
How much of the surrounding town visitors reached beyond the event site. This is the evidence a BIA or a council needs to show the benefit was not confined to the venue.
Year-over-year change
The same measures against last year's event, with the same method. Historical data goes back up to 24 months, so you can often measure last year's event after the fact.
An example
A recurring downtown event in the Niagara region used this approach for its municipal and funding partners. Comparing the event weekend with surrounding weekends across two years:
- event-weekend traffic was 48% higher than surrounding weekends;
- visitors from beyond 15 km rose from 49% to 62%;
- Thursday's share of weekend traffic grew from 32% to 43%;
- visitors reached 66% of the town's blocks.
You can read the full case study.
Where mobile location data does not help
Be clear with your funders about this.
- It does not give a headcount. The data covers a large sample of devices, never everyone. Results are shares and indexes, not attendance. You still need your own ticket, gate or count-based estimate.
- It does not show spending. It records that a device was at a location, not what anyone bought. Spending per visitor still has to come from a survey, a provincial model, or another source.
- It does not know why someone came. It cannot tell a festival-goer from someone who was downtown for another reason, so it does not settle the casuals question on its own.
- It complements, it does not replace. The strongest funding case uses all three: your count, the visitor share from location data, and a spending source.
Putting it together
A practical approach for your next final report:
- Use your gate count or attendance estimate as the base.
- Apply the visitor origin share from location data to split it into local and non-local visitors. Ask your data provider for origin bands that match your funder's definition. For Experience Ontario and TREIM, the line is 40 km.
- Take spending per visitor from a short survey (it only needs to answer the spending question now, not origin) or from a model.
- Run the result through TREIM, if it is available, or whatever model your funder accepts.
- Add the lift, day-pattern and spread results as supporting evidence of what the event did for the area.
- Repeat with the same method next year, so the trend is comparable.
State the method in the report. Funders trust figures that show their workings. Our Event Impact Reports are built around this approach.
FAQ
Can mobile data tell us how many people attended?
No. It measures a large sample of devices, not everyone, so it reports shares and indexed change. Pair those shares with your own ticket or gate counts.
Do we still need a survey?
For spending, usually yes, unless you use a model's default spending figures. But the survey no longer has to carry the visitor-origin question, which is the part that most often fails.
Does Experience Ontario accept location data as evidence?
The 2026 guidelines ask for supporting evidence of performance metrics and list visitor analysis among the materials recipients may provide. The guidelines themselves do not name specific data sources. The final report is filed through the Transfer Payment Ontario portal, which may ask for more detail. Check with your program contact about what they will accept for your event.
Can we measure an event that already happened?
Yes, if it took place within the last 24 months.
Is this privacy compliant?
The data is aggregated and anonymized, with no personal information, and our method follows PIPEDA and provincial privacy rules. If you have questions about your own obligations, get advice for your situation.
How long does a report take?
A first report usually takes 2 to 3 weeks from when the area and dates are agreed.
Next step
Want to see what your last event looked like? Request a Sample Insight. It is complimentary and takes about a week.