So what’s really at stake in this year’s election? Well, among other things, the fate of the planet.

Last year was the hottest on record, by a wide margin, which should — but won’t — put an end to climate deniers’ claims that global warming has stopped. The truth is that climate change just keeps getting scarier; it is, by far, the most important policy issue facing America and the world. Still, this election wouldn’t have much bearing on the issue if there were no prospect of effective action against the looming catastrophe.

But the situation on that front has changed drastically for the better in recent years, because we’re now achingly close to achieving a renewable-energy revolution. What’s more, getting that energy revolution wouldn’t require a political revolution. All it would take are fairly modest policy changes, some of which have already happened and others of which are already underway. But those changes won’t happen if the wrong people end up in power.

To see what I’m talking about, you need to know something about the current state of climate economics, which has changed far more in recent years than most people seem to realize.

How rich do we need the rich to be?

That’s not an idle question. It is, arguably, what U.S. politics are substantively about. Liberals want to raise taxes on high incomes and use the proceeds to strengthen the social safety net; conservatives want to do the reverse, claiming that tax-the-rich policies hurt everyone by reducing the incentives to create wealth.

Now, recent experience has not been kind to the conservative position. President Obama pushed through a substantial rise in top tax rates, and his health care reform was the biggest expansion of the welfare state since L.B.J. Conservatives confidently predicted disaster, just as they did when Bill Clinton raised taxes on the top 1 percent. Instead, Mr. Obama has ended up presiding over the best job growth since the 1990s. Is there, however, a longer-term case in favor of vast inequality?

It won’t surprise you to hear that many members of the economic elite believe that there is. It also won’t surprise you to learn that I disagree, that I believe that the economy can flourish with much less concentration of income and wealth at the very top. But why do I believe that?

I find it helpful to think in terms of three stylized models of where extreme inequality might come from, with the real economy involving elements from all three.

Do you remember the “Bush boom”? Probably not. Anyway, the administration of George W. Bush began its tenure with a recession, followed by an extended “jobless recovery.” By the summer of 2003, however, the economy began adding jobs again. The pace of job creation wasn’t anything special by historical standards, but conservatives insisted that the job gains after that trough represented a huge triumph, a vindication of the Bush tax cuts.

So what should we say about the Obama job record? Private-sector employment — the relevant number, as I’ll explain in a minute — hit its low point in February 2010. Since then we’ve gained 14 million jobs, a figure that startled even me, roughly double the number of jobs added during the supposed Bush boom before it turned into the Great Recession. If that was a boom, this expansion, capped by last month’s really good report, outbooms it by a wide margin.

Does President Obama deserve credit for these gains? No. In general, presidents and their policies matter much less for the economy’s performance than most people imagine. Times of crisis are an exception, and the Obama stimulus plan enacted in 2009 made a big positive difference. But that stimulus faded out fast after 2010, and has very little to do with the economy’s current situation.

2015 was, of course, the year of Donald Trump, whose rise has inspired horror among establishment Republicans and, let’s face it, glee — call it Trumpenfreude — among many Democrats. But Trumpism has in one way worked to the G.O.P. establishment’s advantage: it has distracted pundits and the press from the hard right turn even conventional Republican candidates have taken, a turn whose radicalism would have seemed implausible not long ago.

After all, you might have expected the debacle of George W. Bush’s presidency — a debacle not just for the nation, but for the Republican Party, which saw Democrats both take the White House and achieve some major parts of their agenda — to inspire some reconsideration of W-type policies. What we’ve seen instead is a doubling down, a determination to take whatever didn’t work from 2001 to 2008 and do it again, in a more extreme form.
Start with the example that’s easiest to quantify, tax cuts.

Big tax cuts tilted toward the wealthy were the Bush administration’s signature domestic policy. They were sold at the time as fiscally responsible, a matter of giving back part of the budget surplus America was running when W took office. (Alan Greenspan infamously argued that tax cuts were needed to avoid paying off federal debt too fast.) Since then, however, over-the-top warnings about the evils of debt and deficits have become a routine part of Republican rhetoric; and even conservatives occasionally admit that soaring inequality is a problem.

OAKLAND – For the past decade, much attention has been paid to Greece’s public finances. And when, in November, the country faced the first review of its reform progress under its latest agreement with its creditors – an exercise required to obtain a new infusion of bailout funds – its budget deficit was put under the microscope once again.

But Greeks would do well to consider another type of deficit – one that has received far less public scrutiny, but could have economic consequences that are just as serious. Like the rest of the Mediterranean region (and indeed the entire world), Greece is not just running a fiscal deficit; it is also running an ecological one.

According to our analysis, Mediterranean countries currently use 2.5 times more ecological resources and services than their ecosystems can renew. Greece, for example, would need the total ecological resources and services of three Greeces in order to meet its citizens’ demand on nature for food, fiber, timber, housing, urban infrastructure, and carbon sequestration. Athens alone demands 22% more from nature than the entire country’s ecosystems can provide. And, after years of recession during which pressure on Greece’s natural resources declined, demand has begun to rise again, as GDP growth has shown some improvement.

We live in an era of political news that is, all too often, shocking but not surprising. The rise of Donald Trump definitely falls into that category. And so does the electoral earthquake that struck France in Sunday’s regional elections, with the right-wing National Front winning more votes than either of the major mainstream parties.

What do these events have in common? Both involved political figures tapping into the resentments of a bloc of xenophobic and/or racist voters who have been there all along. The good news is that such voters are a minority; the bad news is that it’s a pretty big minority, on both sides of the Atlantic. If you are wondering where the support for Mr. Trump or Marine Le Pen, the head of the National Front, is coming from, you just haven’t been paying attention.

But why are these voters making themselves heard so loudly now? Have they become much more numerous? Maybe, but it’s not clear. More important, I’d argue, is the way the strategies elites have traditionally used to keep a lid on those angry voters have finally broken down.
Let me start with what is happening in Europe, both because it’s probably less familiar to American readers and because it is, in a way, a simpler story than what is happening here.

NEW YORK – This week, Angus Deaton will receive the Nobel Memorial Prize in Economics “for his analysis of consumption, poverty, and welfare.” Deservedly so. Indeed, soon after the award was announced in October, Deaton published some startling work with Anne Case in the Proceedings of the National Academy of Sciences – research that is at least as newsworthy as the Nobel ceremony.

Analyzing a vast amount of data about health and deaths among Americans, Case and Deaton showed declining life expectancy and health for middle-aged white Americans, especially those with a high school education or less. Among the causes were suicide, drugs, and alcoholism.

America prides itself on being one of the world’s most prosperous countries, and can boast that in every recent year except one (2009) per capita GDP has increased. And a sign of prosperity is supposed to be good health and longevity. But, while the US spends more money per capita on medical care than almost any other country (and more as a percentage of GDP), it is far from topping the world in life expectancy. France, for example, spends less than 12% of its GDP on medical care, compared to 17% in the US. Yet Americans can expect to live three full years less than the French.

For years, many Americans explained away this gap. The US is a more heterogeneous society, they argued, and the gap supposedly reflected the huge difference in average life expectancy between African Americans and white Americans.

According to the economist Kevin O’Rourke, who has been doing a running comparison between the Great Depression that began in 1929 and the Great Recession that began almost eight years ago, the world has just passed a sad landmark. While the initial slump this time around wasn’t nearly as bad as the collapse from 1929 to 1933, the recovery has been much weaker — and at this point world industrial production is doing worse than it did at the same point in the 1930s. A remarkable achievement!

But the bad news is unevenly distributed. In particular, Europe has done very badly, while America has done relatively well. True, U.S. performance looks good only if you grade on a curve. Still, unemployment has been cut in half, and the Federal Reserve is getting ready to raise interest rates at a time when its counterpart, the European Central Bank, is still desperately seeking ways to boost spending.

Now, I believe that the Fed is making a mistake. But the fact that hiking rates is even halfway defensible is a sign that the U.S. economy isn’t doing too badly. So what did we do right?

The answer, basically, is that the Fed and the White House have mostly worried about the right things. (Congress, not so much.) Their actions fell far short of what should have been done; unemployment should have come down much faster than it did. But at least they avoided taking destructive steps to fight phantoms.

Last week I wrote about what in our macroeconomic models has and hasn’t worked since 2008. As I said, demand-side events have been very much what people using IS-LM would have predicted (and did). But on the supply side, not so much. For one thing, the “accelerationist” doctrine that has dominated economic discussion of inflation and unemployment for 40 years has fallen flat. If inflation had responded to the Great Recession and aftermath the way it did in previous big slumps, we would be deep in deflation by now; we aren’t.

Now, the usual response from model-oriented public officials and research staff at policy institutions is to say that what they work with now is a Phillips curve with “anchored” expectations. The idea is that price- and wage-setters now act as if they expect policymakers to hit their 2 percent target, and don’t change their expectations in the face of recent experience. Operationally, of course, such a curve looks just like the old, pre-NAIRU Phillips curves people estimated in the 1960s. And the truth is that such curves fit pretty well on data since 1990.

How is a 74-year-old self-described Democratic socialist from one of the least populous states in the country turning the Democratic primary upside down and proving an adept challenger to one of the most established candidates in modern politics?

Easy, supporters of Senator Bernie Sanders say: He represents an unyielding crusader who will restore decency to American politics. Mr. Sanders is ideologically pure at a time when everything and everyone else in Democratic Washington seems to revolve around compromise. And as this primary is proving, many Democrats (and even some Republicans) are frustrated with compromise. In some way, Mr. Sanders’s appeal stems from his own un-electability.

But first, an exploration of the facts: Before Hillary Clinton announced her candidacy, political observers expected her to run away with the Democratic nomination. And that conventional wisdom appeared to pay off, at first. Mrs. Clinton still leads Mr. Sanders by roughly 25 points in national polls — the same spread that there is between Donald J. Trump, the Republican front-runner, and Mike Huckabee, the trailing former Arkansas governor. Still, the gentleman from Vermont has succeeded in neighboring New Hampshire, where he is virtually tied with Mrs. Clinton.

To understand how Mr. Sanders has outperformed expectations in the Democratic primary, you have to look at how he’s long been outperforming expectations in Washington, where he first arrived after winning a seat in Congress in 1990.