There is a difference between a place where people spend money and a place where people spend time.

For years, economic development has understandably focused on getting people through the door. Cities measure visitors, event attendance, hotel stays, restaurant sales, retail occupancy and any number of other indicators that tell us whether people are coming.

But I think we are missing another measurement that may be just as important: how long they stay once they get there.

Think about the economics of a typical shopping trip. You need something, so you drive to the store that sells it. You park, make the purchase, get back in your car and leave. The business got exactly what it wanted, but there wasn’t much opportunity for anyone else to benefit from your presence.

Now think about the last place you spent an entire afternoon without planning to.

Maybe you originally went there for lunch. Afterward you walked around. Someone wanted coffee. You noticed a store. You ran into somebody you knew. A drink sounded good. Eventually it was close enough to dinner that you started thinking about staying for that too.

Your original reason for being there may have cost you $25. Your decision to stay there for three hours could easily have been worth several times that amount to the surrounding businesses.

More importantly, nobody had to market those additional purchases to you before you arrived.

The place created them.

That distinction deserves more attention from people who think about cities and economic development.

We have become very good at creating destinations. A shopping center is a destination. A restaurant can be a destination. A stadium is a destination. You drive there because you have a specific reason to go, and when that reason has been satisfied, you leave.

Great places behave differently. They keep presenting you with another reason to stay.

That has enormous economic implications.

Digital marketers have understood the value of time for decades. If someone visits a website and leaves after eight seconds, we consider that a problem. If they stay for fifteen minutes, browse six pages and look at several products, we consider that engagement. Businesses spend fortunes studying what causes people to stay, browse and eventually purchase something they had no intention of purchasing when they arrived.

Yet we don’t always apply the same thinking to physical places.

Amazon would never design its website so that you could purchase exactly what you came for without seeing another product. A lot of our commercial development effectively does exactly that.

We make it extraordinarily easy to drive directly to a business, park immediately in front of it, complete a transaction and disappear.

Convenient? Absolutely.

But convenience and economic productivity aren’t always the same thing.

This is one reason I think the concept of parking once deserves more attention, particularly in places like South Florida where pretending people are suddenly going to stop driving isn’t realistic.

The question doesn’t have to be whether people drive. The better question might be what happens after they park.

If someone drives downtown for dinner and then drives three blocks to get dessert, those are two separate trips with two opportunities to simply go home. If the environment makes it comfortable and interesting to walk those three blocks instead, something else happens along the way. They pass storefronts. They see other restaurants. They discover businesses they didn’t know existed. They become familiar with the area.

They may not spend another dollar that night.

But perhaps two weeks later they remember the store they walked past.

This is where the economics of place become difficult to measure using our traditional tools.

What is a shade tree worth to a restaurant?

On a balance sheet, probably nothing.

But what if shade makes people comfortable enough to walk another block during a Florida afternoon?

What is an attractive old building worth to the coffee shop next door?

What is a bench worth to the ice cream shop across the street?

What is good lighting worth at 9:30 at night if it makes people comfortable enough to stay after dinner instead of heading home?

We usually put those things into categories such as beautification, streetscape improvements, public amenities or quality of life. I think that understates their economic function.

They influence behavior.

And behavior is ultimately what produces economic activity.

This may also explain something I’ve observed repeatedly about successful restaurant districts. One good restaurant can sometimes accomplish more for a struggling block than an elaborate redevelopment strategy.

The restaurant gives people a reason to come.

Once enough people are there, someone else begins looking at the vacant storefront next door differently. A location that looked risky six months earlier suddenly looks interesting because there are now 300 potential customers walking past it every night.

Then another business opens.

Now people have two reasons to come.

Eventually they have five.

At some point, the neighborhood itself becomes the destination rather than any individual business within it.

That is a very different economic condition.

It is also why beauty, architecture and public space shouldn’t automatically be dismissed as the softer side of economic development.

People routinely drive past perfectly adequate restaurants to eat somewhere with atmosphere. They pay more for apartments in neighborhoods where they can walk outside and find something interesting. Businesses pay premiums to locate in districts where their customers already want to be.

There is economic value in enjoying where you are.

The problem is that it is much easier to measure the cost of making a place attractive than the value created by people wanting to remain there.

A city council can see exactly what 50 new trees cost.

It’s considerably harder to put a number on the additional restaurant tabs, retail purchases, leases, property investment and repeat visits those trees might indirectly help generate over the next twenty years.

That doesn’t mean the value isn’t there.

It means we haven’t gotten particularly good at measuring it.

I would love to see cities begin studying what I think of as physical dwell time with the same seriousness businesses study digital dwell time.

Not simply how many people attended an event or visited downtown, but what they did afterward. How long they stayed. How many establishments they visited. Whether they parked once. Whether an evening visitor also became a restaurant customer. Whether someone who came for lunch was still there two hours later.

The answers might change some of our assumptions about economic development.

We might discover that attracting another visitor isn’t always the highest-value objective.

Sometimes the person we should be thinking about is already there.

We just need to give them a reason not to go home yet.