Police Release Thermal Imaging Video of Suspect’s Capture

The Massachusetts State Police on Sunday released new video showing the final moments of Friday night’s standoff with Dzhokhar Tsarnaev, 19, before he was taken into custody.

The three-minute long video, which shows images captured with thermal imaging technology, shows Mr. Tsarnaev hiding under a plastic cover in a boat in at a residence in Watertown, Mass., and, later, a robotic arm attached to a vehicle being used to pull the tarp back.

There is also what appears to be an explosion. Police said they used several “flash-bang” grenades, non-lethal explosive devices used to temporarily disorient the suspect.

After a neighbor reported that a bloody man was hiding in his boat, the police swarmed to the scene and Mr. Tsarnaev initially exchanged gunfire with the police, according to law enforcement officials.

An F.B.I. hostage negotiator, who kept his distance, communicating from the second floor of the nearby home, began talking to Mr. Tsarnaev and eventually convinced him to surrender, according to the Watertown Police Chief Edward Deveau.

“A hostage negotiator talked to him for about 25 minutes and talked him into climbing out of the boat,” according to one law enforcement official.

There were several SWAT teams present, but the F.B.I. team initially took him into custody and then allowed members of one of the local police teams to cuff Mr. Tsarnaev, the official said.

Police Release Thermal Imaging Video of Suspect’s Capture

The Massachusetts State Police on Sunday released new video showing the final moments of Friday night’s standoff with Dzhokhar Tsarnaev, 19, before he was taken into custody.

The three-minute long video, which shows images captured with thermal imaging technology, shows Mr. Tsarnaev hiding under a plastic cover in a boat in at a residence in Watertown, Mass., and, later, a robotic arm attached to a vehicle being used to pull the tarp back.

There is also what appears to be an explosion. Police said they used several “flash-bang” grenades, non-lethal explosive devices used to temporarily disorient the suspect.

After a neighbor reported that a bloody man was hiding in his boat, the police swarmed to the scene and Mr. Tsarnaev initially exchanged gunfire with the police, according to law enforcement officials.

An F.B.I. hostage negotiator, who kept his distance, communicating from the second floor of the nearby home, began talking to Mr. Tsarnaev and eventually convinced him to surrender, according to the Watertown Police Chief Edward Deveau.

“A hostage negotiator talked to him for about 25 minutes and talked him into climbing out of the boat,” according to one law enforcement official.

There were several SWAT teams present, but the F.B.I. team initially took him into custody and then allowed members of one of the local police teams to cuff Mr. Tsarnaev, the official said.

Scientific Management Redux: The Difference Is in the Data

I wrote a Sunday column about the rise of what is being called “work force science.” Lots of companies are embracing the trend, but anyone familiar with business history might reasonably ask, What’s really new here?

Certainly, the current enthusiasm for worker measurement and trait testing has its echoes in the past. Frederick Winslow Taylor’s time-and-motion studies of physical labor, like bricklaying and shoveling coal, became the “scientific management” of a century ago.

And for decades, major American corporations employed industrial psychologists and routinely gave job candidates personality and intelligence tests.

Companies pulled back from such statistical analysis of employees in the 1970s, amid questions about its effectiveness, worker resistance and a wave of anti-discrimination lawsuits. Companies apparently figured that if any of their test results showed women or minorities doing poorly, it might become evidence in court cases, said Peter Cappelli, director of the Center for Human Resources at the University of Pennsylvania’s Wharton School.

Today, worker measurement and testing is enjoying a renaissance, powered by digital tools.

What is different now, said Mitchell Hoffman, an economist and postdoctoral researcher at the Yale School of Management, is the amount and detail of worker data being collected. In the past, he said, studies of worker behavior typically might have involved observing a few hundred people at most â€" the traditional approach in sociology or personnel economics.

But a new working paper, written by Mr. Hoffman and three other researchers, mines data from companies in three industries â€" telephone call centers, trucking and software â€"- on a total of more than one million job applicants and more than 70,000 workers over several years.

The measurements can be quite detailed including call “handle” times and customer satisfaction surveys (call centers), miles driven per week and accidents (trucking), and patent applications and lines of code written (software).

Their subject is worker referrals, and the paper is titled, “The Value of Hiring Through Referrals.”

Selecting new workers who are recommended by a company’s current employees has long been seen as a way to increase the odds of hiring productive workers. It makes sense that the social networks of a company’s workers would be a valuable resource to tap, and many companies pay their employees referral bonuses.

The researchers found that referred employees â€" across the three industries â€" were 25 percent more profitable than nonreferred workers. But the referral payoff comes entirely from recommendations from a company’s best workers, whose productivity is above average.

“A recommendation from Joe Shmoe the dud is worse than hiring a nonreferred worker,” Mr. Hoffman noted.

The paper suggests that companies might want to rethink across-the-board referral policies.

“The previous work on worker referrals has been mostly anecdotal and impressionistic,” said Stephen Burks, an economist at the University of Minnesota, Morris, who was a co-author of the paper. “It hasn’t been quantified in this way before, the way you can with these rich data sets.”

But another co-author, Bo Cowgill, points to a challenge in work force science, and for much of the emerging social science using Big Data. Mr. Cowgill, a doctoral student at the University of California, Berkeley, spent six years as a quantitative analyst at Google. So he has plenty of first-hand experience in sophisticated data handling.

The data in work force science is observational data rather than data from experiments, which is the gold standard in science. What much of Big Data research lacks, Mr. Cowgill said, is the equivalent rigor of randomized clinical trials in drug-testing. That is, controlled experiments.

Observing how large numbers of people behave, Mr. Cowgill noted, can be extremely valuable, pointing to powerful correlations. But without controlled experiments, he added, you often do not get to the deeper understanding of the causes of observed behavior â€" understanding causation rather than merely identifying correlation.

“Some people feel that knowing correlations are enough,” Mr. Cowgill said. “Not me, and most economists would agree.”

But other economists say this kind of Big Data research is just getting under way â€" and already yielding significant results. “I wouldn’t sell short being able to see the correlations,” said Erik Brynjolfsson, an economist at M.I.T.’s Sloan School of Management. “That is a big step in itself. And this is the way science works. You start with measurement and it progresses to experiment.”

San Francisco Hangout Becomes Casualty of Tech Boom

Since 1999, The Grove restaurant, with its warm, woodsy interior and comfort food, has marketed itself as “San Francisco’s living room.” Its customers, who have a habit of lingering for hours, seem to agree.

That year, The Grove opened its flagship restaurant on Chestnut Street, in San Francisco’s tony Marina district, where Brian Wilson, the Giants’ quirky, former closer, is occasionally spotted completing crossword puzzles in a corner and disheveled techies, who keep late hours, come for the all-day breakfast.

The Grove acquired such a following over the past decade that its owners have opened three more locations around the city. But they recently announced that they’ll be closing the Chestnut Street location because of untenable rents â€" driven up, in large part, because of the well-paid techies who chow down on its huevos rancheros every day.

This year, the landlords raised the annual rent to $246,816, or roughly $20,000 a month, for the 1,500 square foot ground floor space. That is 50 percent higher than what The Grove’s owners paid five years ago. They said the only way they could possibly keep pace would be to drastically raise prices.

“It’s such a unique restaurant â€" it has an amazing product, a well-priced product â€" and it’s upsetting to think that their business model can no longer survive,” said Katie Spalding, a local interior designer. “To pay rent, they’ll either have to have astronomical prices, which will drive away customers, or go out of business.”

“It’s our favorite brunch spot,” Ms. Spalding added. “It will be really sad if it becomes just another bar.”

Regulars complain that The Grove’s planned closure is just the latest confirmation that the tech boom is making San Francisco unlivable, and pricing long-time businesses and residents out of the market. As start-ups and established tech companies like Google, Facebook and Square poach one another’s engineers with high salaries, rents are, on average, up almost 8 percent from a year ago, to $2,768 for an apartment in a large complex, according to RealFacts, a Novato, Calif., company that tracks real estate prices.

According to a report last month by the National Low Income Housing Coalition, 4 of the 10 most expensive housing markets in the country â€" San Francisco, San Mateo, Santa Clara and Marin counties â€" are in the greater Bay Area. Even Oakland, once a cheaper alternative to the city, saw average rent surge 11 percent in 2012 over the previous year.

Those lucky enough to live in rent-controlled apartments say they fear that they can never afford to move. Those who are not so lucky say the rent increases have left them with little choice but to leave the city.

One apartment seeker, Melissa Jensen, said she recently moved from Los Angeles where she paid less than $2,000 for a one-bedroom in a nice neighborhood. “To get that same space in San Francisco I’m realizing I’m going to have to pay twice that much,” said Ms. Jensen, who is working to open a Northern California branch of The Help Company, a Los Angeles-based boutique staffing firm.

She compared apartment open houses to “cattle calls.” She said she had offered to pay one landlord six months rent up front, thinking that might do the trick, but he told her she was competing with others who were already in an all-out bidding war for the space. “There are young people with disposable incomes who make over $200,000 a year who are willing to pay whatever it takes,” she sighed. “It’s impossible.”

The Grove’s owners are looking for alternative locations in more affordable neighborhoods â€" if those still exist. But back on Chestnut Street last Friday morning, most of their patrons seemed oblivious to the impending closure. They were busy talking tech and, it seemed, too engulfed in the huevos rancheros.

Today’s Scuttlebot: Kickstarter Jr. and Google in Utah

The technology reporters and editors of The New York Times scour the Web for important and peculiar items. For Thursday, selections include a look at how easy it is to create a fake person on the Web, hackers using reports of bad news to spread bad software and a criticism of an amateur manhunt on Reddit in the Boston bombings.