Riding to LaGuardia at the end of a business trip to New York City this past Saturday, my cab plained of the traffic in Midtown. In a non-malicious way (for a New Yorker), he suggested that the general increase in recent times might be due to the ride-sharing service Uber.

Generally speaking, I like Uber. I can only say “generally,” because I haven’t actually tried it yet. It’s a good idea though, as far as I’m concerned (shhh, don’t tell Hilary Clinton).

Nevertheless, call me old-fashioned or sentimental, but I still prefer a yellow cab. This is likely in part due to the fact that Grand Rapids, MI, where I live, has never had a thriving taxi business. For the most part, everyone either owns a car or takes the bus, so riding in a taxi feels like I get to be a part of every movie ever set in New York City to me. It’s at least a little magical, you know, like Die Hard 3.

Anyway, to get back to my cab driver, whose name I regret to have forgotten, I wondered if perhaps he was right. A recent article at FiveThirtyEight by Carl Bialik, Reuben Fischer-Baum and Dhrumil Mehta actually explores some data on NYC taxi and Uber business. They write that in the Manhattan core area,

The increase in total Uber and taxi pickups during evening rush hours and later at night wasn’t spread evenly between the peting services. Instead, Uber pickups surged by more during that time than they did the rest of the day, while taxi pickups experienced their biggest drops.

So Uber isn’t just poaching cab rides, it’s getting some business from people who wouldn’t have taken a taxi. And outside of the Manhattan core the effect is even sharper:

The picture is very different when you look outside the Manhattan core, in the other four New York City boroughs and northern Manhattan. In these areas, Uber added substantially to the number of for-hire vehicles on the street throughout the day.

This is set somewhat in contrast to a statement from Uber:

Uber maintains that any increase it is generating in overall traffic is minimal.

“As I was over the summer, I’m still skeptical this is having an impact on congestion in a material way,” Josh Mohrer, general manager of Uber in New York City, said in a telephone interview. He pointed out that our analysis doesn’t consider whether Uber is replacing rides in private cars or by other panies. “Uber is taking lots of cars off the road and will continue to do that,” he said.

So on the one hand, it seems incorrect to say that Uber is just poaching taxi rides, and notably my driver did not make this claim. Indeed, plaint that Uber is adding traffic would require Uber to be doing more than displacing a fixed number of for-hire rides.

On the other hand, I’m a bit skeptical of Mohrer’s optimism. Is Uber “taking lots of cars off the road”? Or is its relative pared to taxis taking people off of the subway and bus? And are people now less likely to walk a long distance if they think a more affordable for-hire service can get them there?

I don’t have the answer to those questions, but I do have a plication. It may be that Uber isn’t adding too many cars to the total number on the road, but that Uber is still significantly contributing to increased congestion.

Probabilist Nassim Nicholas Taleb explains in his book Antifragile,

[I]ncrease the number of cars by 10 percent and watch the travel time jump by 50 percent…. [T]he average number of cars on the road does not matter at all for traffic speed. If you have 90,000 cars for one hour, then 110,000 cars for another hour, traffic would be much slower than if you had 100,000 cars for two hours.

He continues to summarize his point: “So travel cost is fragile to the volatility of the number of cars on the highway; it does not depend so much on their average number. Every additional car increases travel time more than the previous one.”

Most people have experienced this effect, even outside of NYC. It happens at rush hour in every city in the world. For a while traffic can handle the increase in cars just fine. But after a certain tipping point, pounds by the car.

For Taleb, there is a greater lesson here: “This is a hint to a central problem of the world today, that of the misunderstanding of nonlinear response by those involved in creating ‘efficiencies’ and ‘optimization’ of systems.”

It is a nonlinear problem because if you graphed number of cars on the road on one axis of a graph and travel time on another, travel time does not increase on a straight trajectory with the volume of cars. Instead, after a point, it shoots up exponentially.

Taleb then gives an example from economics:

We can see applications of the point across economic domains: central banks can print money; they print and print with no effect (and claim the “safety” of such a measure), then, “unexpectedly,” the printing causes a jump in inflation…. Alas, the tools (and culture) of policy makers are based on the overly linear, ignoring these hidden effects.

We may relate this same principle to our spiritual life as well. A person who is careless about little temptations will find themselves surprised when they fall into a large one.

I few years ago, I wrote about this in Touchstone:

Among Christians today, there is often shock when an elder, pastor, or prominent member of a congregation is exposed as an embezzler, adulterer, drug addict, or worse. Indeed, such a revelation is rightly called a scandal, because it creates a stumbling block in the way of the Christian life: those who are Christians e disheartened; those who are not dismiss Christianity on its basis.

“How could this happen?” we often ask when a scandal erupts. I propose that the metaphor of the leaven provides the answer.

St. Paul uses the metaphor of leaven to explain how allowing a small sin can eventually work its way through a munity (e.g. 1 Corinthians 5:4-6).

Just like adding a few more cars during rush hour or printing a few more dollars can have dramatic consequences, letting the small stuff go until we are at a tipping point opens us up to sins we thought we’d mit.

However, this principle cuts both ways. Jesus uses the metaphor of leaven in a positive way: “The kingdom of heaven is like leaven, which a woman took and hid in three measures of meal till it was all leavened” (Matthew 13:33).

As I wrote for Touchstone,

Thankfully, the principle of leaven applies in reverse: good yeast works its way through a lump of dough as well as bad. A good first step toward keeping our little bad habits in check is simply making ourselves aware of what they are, but even when we notice them, we may lack the necessary self-control to break them. And this, according to the ancient Church, is precisely where the spiritual e in. They are the leaven in a Christian way of life.

Those who use the spiritual practices of just a little self-discipline and kindness each day open themselves up to opportunities for saintly deeds, should the occasion arise. Even if it doesn’t, they can take joy in fort that sainthood isn’t about what one does so much as it is about who one is on the inside, living a life of genuine repentance.

On the economic side, we can see that a little self-restraint when es to easy-money solutions to economic challenges might help forestall the “unexpected” surprise of unwanted inflation.

As for taxis vs. Uber, well, I think we’ve reached the limit of the positive application. I so no reason to punish either Uber or taxis with extra regulation. The biggest problem is what time people go out on the road, but schedules are not often as flexible as how often one prays or fasts or how much money central banks choose to print.

In that case, at least, there is an additional economic counterbalance: If traffic gets too bad during rush hour, the subway will e a more attractive option again, assuming it has the capacity.

In the meantime, next time you hear plain that Uber is making traffic worse, whether it is or not, remember all the other nonlinear areas of volatility in your life, from the economy to “work[ing] out your own salvation” (Philippians 2:12).