Martin Wolf has written that Krugman is both the "most hated and most admired columnist in the US".
Economist J. Peter Neary has noted that Krugman "has written on a wide range of topics, always combining one of the best prose styles in the profession with an ability to construct elegant, insightful and useful models". Neary added that "no discussion of his work could fail to mention his transition from Academic Superstar to Public Intellectual. Through his extensive writings, including a regular column for The New York Times, monographs and textbooks at every level, and books on economics and current affairs for the general public ... he has probably done more than any other writer to explain economic principles to a wide audience." Krugman has been described as the most controversial economist in his generation and according to Michael Tomasky since 1992 he has moved "from being a center-left scholar to being a liberal polemicist".
From the mid-1990s onwards, Krugman wrote for Fortune (1997–99) and Slate (1996–99), and then for The Harvard Business Review, Foreign Policy, The Economist, Harper's, and Washington Monthly. In this period Krugman critiqued various positions commonly taken on economic issues from across the political spectrum, from protectionism and opposition to the World Trade Organization on the left to supply-side economics on the right.
During the 1992 presidential campaign, Krugman praised Bill Clinton's economic plan in The New York Times, and Clinton's campaign used some of Krugman's work on income inequality. At the time, it was considered likely that Clinton would offer him a position in the new administration, but allegedly Krugman's volatility and outspokenness caused Clinton to look elsewhere. Krugman later said that he was "temperamentally unsuited for that kind of role. You have to be very good at people skills, biting your tongue when people say silly things." In a Fresh Dialogues interview, Krugman added, "you have to be reasonably organized ... I can move into a pristine office and within three days it will look like a grenade went off."
In 1999, near the height of the dot-com bubble, The New York Times approached Krugman to write a bi-weekly column on "the vagaries of business and economics in an age of prosperity". His first columns in 2000 addressed business and economic issues, but as the 2000 US presidential campaign progressed, Krugman increasingly focused on George W. Bush's policy proposals. According to Krugman, this was partly due to "the silence of the media – those 'liberal media' conservatives complain about ..." Krugman accused Bush of repeatedly misrepresenting his proposals, and criticized the proposals themselves. After Bush's election, and his perseverance with his proposed tax cut in the midst of the slump (which Krugman argued would do little to help the economy but substantially raise the fiscal deficit), Krugman's columns grew angrier and more focused on the administration. As Alan Blinder put it in 2002, "There's been a kind of missionary quality to his writing since then ... He's trying to stop something now, using the power of the pen." Partly as a result, Krugman's twice-weekly column on the Op-Ed page of The New York Times has made him, according to Nicholas Confessore, "the most important political columnist in America ... he is almost alone in analyzing the most important story in politics in recent years – the seamless melding of corporate, class, and political party interests at which the Bush administration excels." In an interview in late 2009, Krugman said his missionary zeal had changed in the post-Bush era and he described the Obama administration as "good guys but not as forceful as I'd like ... When I argue with them in my column this is a serious discussion. We really are in effect speaking across the transom here." Krugman says he's more effective at driving change outside the administration than inside it, "now, I'm trying to make this progressive moment in American history a success. So that's where I'm pushing."
Krugman's columns have drawn criticism as well as praise. A 2003 article in The Economist questioned Krugman's "growing tendency to attribute all the world's ills to George Bush", citing critics who felt that "his relentless partisanship is getting in the way of his argument" and claiming errors of economic and political reasoning in his columns. Daniel Okrent, a former The New York Times ombudsman, in his farewell column, criticized Krugman for what he said was "the disturbing habit of shaping, slicing and selectively citing numbers in a fashion that pleases his acolytes but leaves him open to substantive assaults".
Krugman's New York Times blog was "The Conscience of a Liberal", devoted largely to economics and politics.
Five days after 9/11 terrorist attacks, Krugman argued in his column that the calamity was "partly self-inflicted", citing poor pay and training for airport security driven by the transfer of responsibility for airport security from government to airlines. His column provoked an angry response and The New York Times was flooded with complaints. According to Larissa MacFarquhar of The New Yorker, while some people thought that he was too partisan to be a columnist for The New York Times, he was revered on the left. Similarly, on the 10th anniversary of the 9/11 attack on the United States, Krugman again provoked a controversy by accusing on his New York Times blog former U.S. President George W. Bush and former New York City mayor Rudy Giuliani of rushing "to cash in on the horror" after the attacks and describing the anniversary as "an occasion for shame".
Krugman was noteworthy for his opposition to the 2016 presidential campaign of Bernie Sanders. On January 19, 2016, he wrote an article which criticized Bernie Sanders for his perceived lack of political realism, compared Sanders' plans for healthcare and financial reform unfavorably to those of Hillary Clinton, and cited criticisms of Sanders from other liberal policy wonks like Mike Konczal and Ezra Klein. Later, Krugman wrote an article which accused Sanders of "[going] for easy slogans over hard thinking" and attacking Hillary Clinton in a way that was "just plain dishonest".
On the 12 July 2016, Krugman tweeted "leprechaun economics", in response to Central Statistics Office (Ireland) data that 2015 GDP grew 26.3% and 2015 GNP grew 18.7%. The leprechaun economics affair (proved in 2018 to be Apple restructuring its double Irish subsidiaries), led to the Central Bank of Ireland introducing a new economic statistic, Modified gross national income (or GNI*) to better measure the Irish economy (2016 Irish GDP is 143% of 2016 Irish GNI*). The term leprechaun economics has since been used by Krugman, and others, to describe distorted/unsound economic data.
Krugman's use of the term leprechaun to refer to Ireland and its people has raised rebuke. In June 2021, Krugman wrote an article titled, "Yellen's New Alliance Against Leprechauns". Following the article, the Irish Ambassador to the US, Daniel Mulhall, wrote a letter to his publisher saying, "This is not the first time your columnist has used the word 'leprechaun' when referring to Ireland, and I see it as my duty to point out that this represents an unacceptable slur."
Krugman harshly criticized the first Trump administration. In January 2025, speaking on his departure from The New York Times the previous month, Krugman said that he found the back-and-forth with his editor had become intrusive and tiresome. He cited "toning down [his] voice" and "pressure for what I considered false equivalence" as complaints, as well as a desire to publish him less often by removing his newsletter. The Columbia Journalism Review reported that he refused an offer to reduce his regular columns from twice to once a week in exchange for keeping his newsletter.