Lyubov Kostyrya, a pollster, stands in front of an apartment building in Moscow. (Alexander Zemlianichenko Jr/For The Washington Post)

Russian President Vladimir Putin has an 83 percent approval rating. Lyubov Kostyrya’s job is to knock on doors to track it.

Every week, Russian pollsters dispatch an army of workers to canvass the country’s 11 time zones for people’s views on Putin, the economy and other issues. And so Kostyrya visits one home after another to learn what Russians are thinking. Two years after Putin’s ratings skyrocketed at the start of a geopolitical conflict with the West, they have stayed there, week after week, month after month.

On behalf of the Kremlin, pollsters in recent weeks have tracked economic sentiment in struggling industrial towns. They ran a snap survey to test support to spurn an electricity deal with Ukraine that left Crimeans in the dark. And they have kept close track of reactions to cease-fire negotiations with Syrian President Bashar ­al-Assad.

“Survey!” Kostyrya said after she rang the bell of yet another steel-doored apartment in a Soviet-era 12-story complex of identically laid-out dwellings on Moscow’s edge. “Can I ask you a few questions?”

Just over two years ago, as Russia headed toward the Winter Olympics in Sochi, Putin’s poll numbers were slumping. Only 61 percent of Russians approved of his job performance — high by Western standards, but the lowest for Putin since shortly after he took office. After Putin annexed Ukraine’s Crimean Peninsula, then stoked tensions with the West to their worst since the Cold War, Russians took their minds off their struggling economy and positioned themselves resolutely behind their leader.

It is a development that has flummoxed Western nations and frustrated Russia’s motley band of oppositionists. Some of them say that Russians are too scared to speak their minds to pollsters. Others claim that the poll numbers are manipulated, although most Western polling firms arrive at similar figures.

The pollsters say that the Kremlin is keenly interested in the results they turn up every week — and that it quickly reacts when it sees problems that could pose a threat to Putin’s ratings. Even as pocketbook problems have mounted, Putin has launched popular military campaigns in Ukraine and now in Syria.

“Putin is attentive, yes. Fifteen years he’s been in power, but he’s still interested in our data,” said Valery Fedorov, the head of the state-owned Russian Public Opinion Research Center. The organization’s bustling offices suggest that even with the country’s economy in a tailspin, business is booming for those who monitor public opinion on behalf of the Kremlin.

“How can you understand what to do if you can’t understand the people?” Fedorov said.

In the massive apartment building — nearly two football fields long — where Kostyrya conducted the survey on behalf of the Russian Public Opinion Research Center, guests arrived at a birthday party with red roses and cheap bubbly. Teenagers sneaked kisses in the hallway. Toddlers peeked out from behind the legs of their parents.

But many people just shouted through the peephole.

“Oy! I already have a headache!” one woman said when Kostyrya told her that the survey was about politics. Over the course of five hours, Kostyrya conducted just five interviews after knocking on 144 doors — a worse response rate than comparable door-to-door surveys in the United States.

The polling organization allowed a reporter a rare opportunity to accompany one of its workers for a day on the condition that no respondents be identified by name or by specific answers to questions in the survey.

One 62-year-old woman answered the door in a blue daisy-print housedress and slippers. Kostyrya readied the Samsung tablet she used to record responses to the survey. The woman was happy to chat.

“I watch soap operas,” she said. “On TV there’s war, war and nothing but war.” But she said that she trusted Putin — just not the people underneath him.

The main issue on her mind, she said, was the price of medicine. “It’s 500 rubles here, 500 there, 300 here. Prices are so high!” she said. Five hundred rubles, the Russian currency, is about $6.50 — not easy on her pension of $225 a month, she said.

Others said they feared for the future as prices rise and incomes stagnate, turning commonplace groceries into luxuries. Some were skeptical that Russian authorities had a plan to fix Russia’s dependence on oil to power its budget. Many complained about local ­politicians.

A few floors above, a 70-year-old man wearing a thick gray sweater answered the door. He trusted Putin, he said.

“How does he sleep?” the man asked about the president. “He skis. He goes to factory openings to congratulate the workers. He promises them support. He’s in good health.”

Most of the people Kostyrya interviewed drew a sharp line between their support for Putin and their feelings about Russia’s direction, which has taken a sharply negative turn as economic pain accumulates. That is reflected in the polls, which show that support for Putin has barely dropped, even though only 45 percent of Russians believe their country is on the right track, down from 64 percent in June, according to figures from the Levada Center, an independent polling firm.

Analysts said that after the Crimean annexation, Putin became untouchable to a large slice of the population.

“People interpret him as a permanent component of their construction of the world,” said Alexander Oslon, the head of the Public Opinion Foundation, another of Russia’s leading pollsters. “They don’t look at him as a political leader who comes and goes.” But he said that if economic troubles last long enough, even Putin’s rating might be vulnerable.

The Kremlin is so ratings-conscious that it frequently commissions polls on the same topics from several firms simultaneously, pollsters said. It also has an in-house polling agency that does not release numbers publicly and is run by the Federal Guards Service, the Russian equivalent of the Secret Service.

At times, it uses the polling results to bolster struggling regions with extra resources. The Kremlin also trumpets its high ratings to the Russian people through state-run television, creating a feedback loop in which it emphasizes its legitimacy.

“It’s a PR campaign when you already know what the results will be,” said Denis Volkov, an analyst at the Levada Center.

In a nation in which the Kremlin controls the airwaves, opinions can also be easily swayed, because few contrary opinions can be found in the mainstream. In September, weeks before Putin announced Russia’s surprise entrance into the conflict, few Russians saw the Islamic State as a direct threat. Within weeks — and after constant coverage on TV — the number shot up to a solid majority.

But what goes up can also go down. The longtime mayor of Moscow, Yuri Luzhkov, saw his ratings plummet after he was suddenly fired in 2010. Putin critics say that his popularity may be equally fleeting.

“Switch off the television, and this popularity would go away in two months,” said Mikhail Kasyanov, a former prime minister who is now a leading opposition politician.

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