Here’s some Labor Day weekend reading on one of New York’s vexing problems: bike theft, which, is up 25 percent over last year. As of July, 1,694 bikes were reported stolen this year, according to the NYPD, which encourages bike owners to have their frames etched with identifying codes. Actual thefts are likely much higher than the reported number.

Stealing bikes has a relatively low reward compared to other types of theft, yet it remains common. The Priceonomics Blog, run by a company that provides estimates for reselling goods, including bikes, recently looked at why bike theft is so prevalent:

It seems as if stealing bikes shouldn’t be a lucrative form of criminal activity. Used bikes aren’t particularly liquid or in demand compared to other things one could steal (phones, electronics, drugs). And yet, bikes continue to get stolen so they must be generating sufficient income for thieves.

A great number of stolen bikes are resold for cents on the dollar. According to writer Patrick Symmes, who investigated bike theft with the San Francisco Police Department after having his own bicycle stolen, bikes act as one of four forms of “street currency” — the others being cash, sex and drugs. “Of those, only one is routinely left outside unattended,” wrote Symmes.

More advanced thieves resell the bikes for closer to their market value. These bikes often end up on Craigslist, but theft victims have become savvier about keeping an eye out for their wheels online and at flea markets. As a result, these bikes are sometimes shipped and resold in other cities where nobody is looking for them.

In the end, it comes down to risk and reward. Despite the small rewards that bike theft brings to opportunistic criminals, police generally show little to no interest in going after these thefts. As a result, it becomes a virtually risk-free crime.

The NYPD has taken occasional action to crack down on bike theft. The Ninth Precinct, for example, temporarily shut down an East Village bike shop for selling stolen goods; its manager disputed the accusation.

Even though bike theft feels common in many big cities and has received minimal police attention compared to other forms of property theft, it has failed to develop into a truly large-scale underground enterprise, writes Priceonomics:

Criminal masterminds have to value their time and resources, and bike theft isn’t really that profitable […] If you want to get a good price for a stolen bicycle, it requires a decent amount of work. That amount of work is what limits the bike theft trade from really flourishing.

Caroline Samponaro of Transportation Alternatives says that although theft persists in NYC, it’s been less of a scourge in recent years. “I mostly hear from folks that theft feels like less of a problem these days,” she said, despite the recent one-year uptick in NYPD statistics.

With the surge in cycling, Samponaro says one contributing factor to an increase in thefts might be that many new riders do not know how to effectively lock a bicycle. Until bike theft is taken as seriously as other forms of theft, the best defense is locking up correctly. Hal Ruzal can help you out with that.

Enjoy the long weekend, everyone. We’ll see you back here on Tuesday.