STMicro and France to Invest in New Microprocesors

The company, which is based in Geneva, said it planned to spend 1.3 billion euros, or $1.7 billion, through 2017 on new research and development and to expand chip production at its factory in Crolles, France, a town near Grenoble in the French Alps.

France, along with regional and municipal governments in and around Crolles, would contribute an additional 600 million euros to the project, which is part of an industry the government is eager to promote.

France and Italy hold a combined 27.5 percent stake in STMicro, making them the biggest shareholders in the chip maker.

A spokesman for the company, Alexis Breton, said that most of the investment would be used to develop faster and more efficient chips for TV set-top boxes, smartphones and routers to control home security, heating, air and entertainment systems wirelessly.

The market for such chips is expected to grow to 67 billion euros this year, according to World Semiconductor Trade Statistics, an industry research organization in San Jose, Calif. The investment would allow STMicro to double its production capacity of such chips at Crolles, potentially making it a stiffer rival to Broadcom, Texas Instruments, Infineon Technologies and Sony.

Because of the government subsidies involved, the investment must be approved by Joaquín Almunia, the European Union competition commissioner.

STMicro employs 48,000 people, almost half of them in France and Italy, and had sales of $8.5 billion last year.

The company’s factory in Crolles, which employs 2,500 workers, expanded recently with 1.8 billion euros in public and private investments.

But continuing losses at ST-Ericsson, a joint venture with the Swedish equipment maker Ericsson to produce chips for handsets, have put pressure on STMicro, which has reported losses for the past six quarters. The venture with Ericsson is set to close later this year.

In a speech to factory workers in Crolles on Monday, the French prime minister, Jean-Marc Ayrault, said the investment reflected an “exemplary” partnership between private business and local governments, among others. “There are more than 24,000 jobs that depend on this ecosystem,” Mr. Ayrault said.

Twitter Yields to Pressure in Hate Case in France

The case shows how challenging it is for Silicon Valley companies to champion the free speech rights of users while complying with the laws of countries where they do business. It also highlights Silicon Valley’s Europe problem: the Continent represents a large and lucrative market, but its lawmakers, regulators and courts have hounded the industry in recent months on issues as varied as privacy and antitrust law.

For months, Twitter had fought a court order obtained by a private French citizens’ group demanding that the company turn over the user information. But on Friday, the company said it had handed over the information to a prosecutor in Paris, in response to a law enforcement request. By turning over the information, Twitter said, it had ended a lawsuit related to the court order brought by the private group.

In a statement Friday, the company said: “in response to a valid legal request, Twitter has provided the prosecutor of Paris, Presse et Libertés Publiques section of the Paris Tribunal de Grande Instance, with data that may enable the identification of certain users that the Vice-Prosecutor believes have violated French law.”

The statement took pains to note that Twitter was providing the information to law enforcement through a legal request, not to the private group.

The case has important implications for Twitter users worldwide, as governments increasingly try to extract user information from the service. Legal experts say Twitter could have insisted that the French authorities seek to extract the user data by filing a claim in the United States, where the company is based.

Eric Goldman, a law professor at Santa Clara University, said that while Twitter had demonstrated its commitment to protecting free speech on many occasions, it was under pressure to meet nations’ demands for information on their citizens, both in America and abroad. Many companies face this pressure, and Twitter is all the more vulnerable now that it has an office in Paris, making its employees and assets there subject to French law.

“Governments have an unquenchable thirst for more information about their citizens, and Internet companies, as repositories of data, are going to be on the list of targets,” Mr. Goldman said. He added: “We are in no position to criticize another government for demanding data on users. Our government is doing that about us every day.”

The French Union of Jewish Students and SOS Racisme had sought the identities of the users, who had used pseudonyms, and in January a French court ordered Twitter to hand over the data. Twitter appealed, and lost, in June. The French student union filed a $50 million civil suit against the company, saying that it had failed to comply with the court order. On Friday, Jonathan Hayoun, president of the group, said that “Twitter has finally accepted its responsibility for hate prevention as a prominent player on the Web.”

In the second half of 2012, Twitter received over 1,000 requests from government agencies in the United States and abroad, from Australia to Turkey. It complied to varying degrees: 69 percent of the time with respect to requests from American authorities, 33 percent from the Dutch, and never in the case of countries like India, Israel or Turkey. Twitter on Friday said it did not have a uniform policy on how it treated law enforcement requests. “Requests for Twitter user information, whether domestic or international, are evaluated on a case-by-case basis,” the company said in a statement.

“There was more fighting Twitter could have done and chose not to,” said Christopher Wolf, a partner at Hogan Lovells who represents American technology companies, including in Europe. He added: “It is an episode that gives me some pause over the potential breadth of jurisdiction by a European government over a U.S. Internet company.”

Twitter’s legal feuds with foreign governments could muddle its expansion overseas. Running afoul of the law in any country potentially makes it vulnerable to having its assets seized and its employees arrested.

Complicating matters, Twitter, like other similar companies, has a sort of jurisprudence of its own, laid out in its Terms of Service. It does not explicitly address hate speech, but stipulates that “users are allowed to post content, including potentially inflammatory content, provided they do not violate the Twitter Terms of Service and Rules.” Those include a prohibition against “direct, specific threats of violence against others.”

The French case was prompted by a spate of anti-Semitic posts late last year. There were also jokes about the Holocaust and comments denigrating Muslims. Holocaust denial is a crime in France, and the country has strict laws against hate speech. Twitter removed the posts in France after the complaints.

France Télécom Board Backs Chief Executive

Mr. Richard’s grip on the job became uncertain last week after he was placed under formal investigation in connection with what was suspected to be fraud involving a 2008 arbitration case. But in a statement Monday, the board of the company, which is changing its name to Orange, expressed “its full confidence in Stéphane Richard and his ability to effectively meet the numerous challenges facing” the company. “In particular, the board considers that the legal measures affecting Stéphane Richard do not impede his ability to fully and effectively lead Orange as its chairman and chief executive officer.”

The statement said the board had also asked an independent board member, Bernard Dufau, “to follow the situation.”

With its 27 percent stake in France Télécom, the government appoints three of the 15 directors on the board, and its vote tends to be decisive.

Mr. Richard’s continued stewardship at France Télécom, at least for the short term, was essentially secured on Sunday when Mr. Hollande told the M6 television network that the executive had the state’s support, as long as the investigation did not stop him from performing his functions at the company.

“If the judicial procedure takes a turn such that he can no longer lead the enterprise, at that moment another decision will be taken,” Mr. Hollande added.

The company employs about 170,000 people worldwide. Mr. Richard has been chief executive since February 2010 and is credited with helping to restore stability after a major restructuring led by his predecessor caused morale to plunge. Company unions last week called for Mr. Richard to stay on despite the investigation.

Mr. Richard denies any wrongdoing, and a formal investigation does not necessarily lead to charges or trial.

In 2008, he was a top aide to Christine Lagarde, the French finance minister at the time, when a businessman named Bernard Tapie was awarded 403 million euros, or about $538 million, by an arbitration panel to settle a commercial dispute with Crédit Lyonnais, a state-owned bank. Mr. Tapie had been a lifelong Socialist, but he changed parties to support the 2007 election bid of former President Nicolas Sarkozy. Investigators are seeking to find out if Mr. Tapie might have received special treatment, and the state has begun working to overturn the award.

Ms. Lagarde, currently head of the International Monetary Fund, is also being investigated in the case as an assisted witness, a less serious status than formal investigation. She also denies any wrongdoing.

Investors appeared to support Mr. Richard’s expected retention, with shares of France Télécom ending 3.1 percent higher in Paris.

Air Controller Strike in France Causes Cancellations

PARIS — The scene at Charles de Gaulle Airport on Tuesday underscored an all-too-familiar trope about France.

With air traffic controllers on strike, tourists from around the world arrived in Paris to find themselves stranded, many unable to make connecting flights to other parts of the Continent. The three-day strike, which began Tuesday, sought to protest a proposal to accelerate the integration of air traffic management systems across the Continent. But for some it mainly served to highlight France’s stubborn singularity, which has made the country increasingly uncompetitive in European and global marketplaces.

“These strikes always happen, especially during the months of June and July,” said Britt-Marie Stromer, a 70-year-old Swedish retiree. “It doesn’t work like this in other European countries.”

Some 1,800 flights — roughly half of all scheduled flights — were canceled across the country Tuesday, while hundreds more were delayed and disrupted by the spillover in Europe. French aviation officials said they expected as many as 50 percent of flights to be canceled again Wednesday until at least midday Thursday. The controllers are protesting Brussels’s plans to accelerate the integration of the European Union’s fragmented air space, meant to improve transportation efficiency and lower the cost of air travel.

The terminals at Paris area airports were largely calm, because most airlines had managed to warn passengers well in advance. But many travelers still had not gotten the word.

But many passengers said they could not comprehend why France, one of Europe’s biggest tourist destinations, appeared so resistant to changes that economists say have the potential to bolster travel and, with it, economic growth.

“I’m on vacation, which is supposed to be a relaxing time,” said Brittany Beaton, a 28-year-old social worker from Canada who had planned to fly to Barcelona. An alternative flight Air France offered her was too expensive, she said, “so I’m going to try to take a train.”

French airports, airlines and traffic controllers tend to have the reputation of being more strike-prone than their European peers. In reality, analysts say, a number of similarly disruptive labor actions have been undertaken in recent years by workers in Germany, Spain and Britain.

Nonetheless, Tuesday’s events seemed to follow mounting opposition by workers in other sectors of the French economy who continue to resist structural changes aimed at shaving labor and operating costs.

While it was hard to tell on Tuesday, the government of France’s Socialist president, François Hollande, says it actually strongly supports the idea of a unified regional airspace. But French officials do not like the way Brussels is trying to cajole its 27 member states toward that goal.

Since the fall, Siim Kallas, the European transport commissioner, has been trying to turn up the heat on member states like France that are seen to be dragging their feet. It was a decade ago that European officials proposed legislation to replace a crazy quilt of air traffic control fiefs that officials say account for about $6.5 billion in unnecessary costs each year. The measure was passed by the European Parliament in 2009 and subsequently endorsed by France and all other member states.

Last year, Mr. Kallas threatened legal action and fines against member states for not meeting key milestones of the legislation. On Tuesday, he proposed ways to to inject fresh momentum into the process by granting significant new decision-making powers to Eurocontrol, an agency in Brussels that is already responsible for coordinating air traffic flows across the Union and an additional 12 nearby countries.

His proposals include a measure to separate national regulation of air travel from traffic management services, as well as a mandate that state-owned monopoly providers of navigation, weather forecasting, surveillance and other services be privatized. But Mr. Kallas’s proposals require approval from the European Parliament and member states.

It is these proposals that have angered Paris. In an interview Tuesday, France’s transport minister, Frédéric Cuvillier, said the initiative amounted to “regulatory harassment.” He accused Brussels of trying to rush through one-size-fits-all changes that did not take into account differences in the way member states have historically managed their own airspace.

“It is necessary that these things happen in a spirit of respect for differences in national organization,” Mr. Cuvillier said. “We have to give it time.”

And just to show France was not alone, Mr. Cuvillier said he had persuaded his German counterpart, Peter Ramsauer, to sign a joint letter to Mr. Kallas, asking him to delay presenting his new proposals to the European Parliament.

But Mr. Kallas said France, Germany and others have already had plenty of time.

“Our airlines and their passengers have had to endure more than 10 years of reduced services and missed deadlines,” he said Tuesday in Strasbourg. “We need to boost the competitiveness of the European aviation sector and create more jobs in the airlines and at airports.”

For passengers like Alexander Eliassem, a 38-year-old Norwegian, patience with France’s philosophy was wearing thin on Tuesday. He and his exhausted family were off to search for a place to stay for the night after their Lufthansa flight to Oslo was canceled.

“I have a 9-year-old child with me so, yes, it’s a little difficult,” Mr. Eliassem said. He said the airline would partly reimburse him, but only if he stayed in a hotel of no more than three stars in the notoriously generous rating system. “This is France, so that isn’t saying much.”

Catherine Chapman contributed reporting.

DealBook: France Expands Inquiry Into Tax Evasion at UBS

Michael Buholzer/ReutersThe Swiss bank UBS in Zurich.

8:41 a.m. | Updated

PARIS – UBS, the biggest Swiss bank, is the target of a widening tax evasion investigation in France, a spokeswoman for the Paris prosecutor’s office said on Friday, an indication that the lender’s problems with the French government are growing.

A French judge on Thursday placed UBS AG, the Swiss parent company, under formal investigation on suspicion that it illegally sold banking services to French citizens that helped them to set up secret accounts abroad, according to Agnès Thibault-Lecuivre, the spokeswoman for the Paris prosecutor’s office. The Swiss bank also was identified as an ‘‘assisted witness,’’ a less serious status, in a concurrent investigation of suspected money laundering and tax evasion, she said.

The expanded inquiry comes just a week after the bank’s local subsidiary, UBS France, was put under formal investigation on similar suspicions. In the French legal system, a formal investigation, sometimes compared to an indictment in the American system, can drag on for years, and does not necessarily lead to charges or trial. An assisted witness is required to answer prosecutors’ questions with a lawyer present, but is thought less likely to ultimately face charges.

Yves Kaufmann Lobato, a UBS spokesman in Zurich, sought to play down the significance of the latest development, noting that the investigation had been the subject of news reports since early last year.

‘‘We will continue working with the authorities in France within the applicable legal framework to arrive at a resolution to this matter,’’ he added, citing a bank statement.

The investigators are examining the question of whether bankers from the Swiss parent company broke a French law against “illicit solicitation” by actively approaching potential French clients.

According to a report on Friday in the French newspaper Le Monde, UBS bankers regularly sought to ingratiate themselves into networks of affluent people, mingling at sporting events and concerts in order to seek out possible clients for tax evasion. At least 353 French citizens suspected of evading taxes through UBS have been identified, and the French government has sought administrative assistance from the Swiss government in four cases, the newspaper reported, without citing its source.

Mario Tuor, a spokesman for the Swiss Federal Finance Ministry in Bern, declined to comment on the case, saying the details were confidential.

There is a broad push in the United States and Europe to stop offshore banks from aiding tax cheats. Switzerland – where the secrecy laws punish banks for revealing client data – has been in an uncomfortable spotlight. In France, President François Hollande has made ending tax evasion a top priority after his former budget minister, Jérôme Cahuzac, was found to have set up secret Swiss and Singapore accounts to hide some of his wealth.

UBS itself has been under international scrutiny since 2008, when the United States Justice Department threatened to indict it for conspiracy to defraud the Internal Revenue Service. In 2009, UBS eventually agreed to pay a $780 million fine to avoid prosecution, and turned over data on 4,450 client accounts held by United States citizens suspected of evading taxes.

Obama administration officials followed that case with a broad push to expose all the American accounts hidden behind Swiss banking secrecy laws. With about a dozen Swiss lenders facing the possibility of indictment in the United States, the Swiss government agreed last month on a framework for banks to hand over information on American clients, a deal it hoped would permanently end the threat of United States prosecution. That agreement still must be approved by the Swiss legislature.

UBS said on Friday that it ‘‘fully supports the strategy of Switzerland to limit itself to the management of declared assets.’’

‘‘We believe that Switzerland and the countries of the E.U. need to find a solution for the past,’’ according to a statement from the bank. ‘‘This is an industry issue that UBS has taken significant steps to resolve since 2009. UBS does not tolerate any activities intended to help its clients circumvent their tax obligations.’’

As Culture Moves Online, France Tries to Follow It With a Tax

PARIS — France’s “cultural exception” — the policy that creative works like books, music and movies deserve protection beyond what is accorded ordinary goods — is in line for a digital update.

A government adviser has suggested that manufacturers pay a 1 percent levy on the price of smartphones and tablet computers to help keep funding for such works alive, as more and more end up online and beyond the reach of existing taxes.

The tax, “painless for the consumer,” could also be used to ensure that artists are remunerated at a time when so much is downloaded free, said the report, which was presented Monday to President François Hollande and his culture minister, Aurélie Filippetti.

“Considering the weight of cultural content in connected devices, it is legitimate that those who make and distribute the equipment contribute to the financing of its creation,” according to the report, produced under the guidance of a former television executive and journalist, Pierre Lescure.

“L’exception culturelle” is no trifling matter: Nicole Bricq, the French trade minister, warned in March that it was “a red line” that could not be crossed in talks with the United States on a proposed free-trade area. France and 13 other European Union member nations insisted in a letter this week that the audiovisual sector must be left out of those talks, setting up a possible confrontation with the British prime minister, David Cameron, who has said that everything should be on the table.

In practice, the cultural exception means broadcasters must meet quotas for French music and television programming, for example, and prices for books are set by regulators. The effort stretches throughout the economy, requiring a system of taxes and subsidies for its upkeep, perhaps most visibly in the country’s film industry, which gets hundreds of million euros each year in subsidies — raised from taxes on movie tickets, television stations and Internet service providers — to defend itself from the Hollywood juggernaut.

But technology threatens to render such measures irrelevant, the report noted. The nature of Internet commerce means foreigners can have access to the French market without having to pay the levies that support French culture. And as more content is streamed online or stored in the cloud, a tax on recording media like blank compact discs and memory sticks will raise less money — and that is where the smartphone tax comes in.

Gilles Vercken, an intellectual property lawyer, acknowledged that streaming and the cloud would bring down those levies, which he estimated currently raise about €200 million, or $260 million, a year to support French authors, composers, actors, musicians and the like. But he expressed skepticism that the smartphone tax would see the light of day.

“I wonder what could be the legal grounds for such taxes,” he said, noting that the connection between hardware manufacturers and end users might prove a difficult one to defend in court. “I really don’t see it.”

Monica Horten, a visiting fellow at the London School of Economics who studies the politics of intellectual property rights, said that, in principle, such levies were possible under E.U. law, but that “the problem is in the implementation.”

The first issue would be drafting a law acceptable to the European Court of Justice, while another would be in actually getting device makers on board to pay the tax. “I think you can expect them to filibuster,” she said.

The report seeks to address a problem that is as old as the Internet, which has shifted the balance of power away from content creators in favor of newer actors like Google, Amazon and peer-to-peer downloading services, even as it gives creators previously unimagined opportunities to be seen or heard.

In addressing such matters, France has sometimes chosen to fight battles that other governments have shied away from. For instance, Google agreed in February to set up a €60 million fund to help French newspaper and magazine publishers develop their digital business, though it managed to fend off demands that it pay for the right to link to their content.

And the Lescure report comes less than two weeks after Arnaud Montebourg, the minister for industrial renewal, put the kibosh on a sale to Yahoo of a majority stake in Dailymotion, a French rival to YouTube, because the government had singled out the company as a national champion and did not want control falling into foreign hands.

The Lescure report also suggests that France throw out a “three-strikes” anti-piracy law that Nicolas Sarkozy, Mr. Hollande’s predecessor, had held up as one of his signature achievements and one that had been hailed by the global entertainment industry. Under the Hadopi Law, as it is known, illegal downloaders were to have their Internet access cut off if they failed to heed three warnings; violators were also to be subject to criminal sanctions and large fines. In practice, there has been little enforcement action, though proponents credit the law with helping to reduce Internet piracy.

If Mr. Lescure’s recommendations are followed, law enforcement will focus on the worst violators, and most people would face minimal fines. A proposed “Hadopi authority” would be eliminated, and responsibility for enforcement would revert to the national media regulator, the Conseil supérieur de l’audiovisuel.

Bundesbank President Says France Needs to Control Its Deficit

FRANKFURT — The head of the German central bank said Monday that France should not give up trying to bring its government deficit below 3 percent of gross domestic product, adding to the criticism being heaped on President François Hollande of France from abroad.

Jens Weidmann, president of the Bundesbank, cloaked his rebuke in the language of French-German solidarity and was considerably more diplomatic than Maurice M. Taylor Jr., the head of the American tire maker Titan International, who sparked a furor last week when he told the French industry minister that French workers were lazy.

Still, Mr. Weidmann was the latest prominent person to lecture the increasingly defensive French on how they should manage their economy.

Speaking in Paris at the École des Hautes Études Commerciales, a leading business school, Mr. Weidmann noted that unemployment in France was above 10 percent while France’s share of world exports had declined by 25 percent since the euro made its debut. Total government debt “has reached a level that could potentially hurt growth,” Mr. Weidmann said.

France would undermine confidence in its prospects if it delayed efforts to control deficit spending, he said.

“Putting consolidation off would just shift the problem into the future,” Mr. Weidmann said, according to an advanced text of his remarks. “It would buy time but in so doing also worsen matters today as there is the risk that trust in public finances would erode even more.”

The tone of Mr. Weidmann’s speech was polite and even included a joke at Germany’s expense. (“How many Germans do you need to change a light bulb? One: he holds the light bulb, and the rest of Europe revolves around him.”)

Mr. Weidmann invoked the durable, if sometimes contentious, relationship between France and Germany, which has always been crucial to the functioning of the European Union. “Only together can France and Germany solve the current crisis,” he said.

But he said that the largest countries in the European monetary union had a responsibility to set an example for other members. “It is in my view particularly important for the heavyweights in E.M.U. to give clear signals,” he said.

France’s government budget deficit will be 3.7 percent of gross domestic product this year, while Germany will have a slight surplus, the European Commission forecast last week. When European countries formed a common currency, they agreed to keep their deficits below 3 percent of G.D.P., though the target has often been breached.

Mr. Weidmann acknowledged that budget austerity might hurt growth but said countries had no choice. “It is important that governments adhere to the consolidation plans they announced,” he said. “This will inspire confidence, which is an important prerequisite for the economy to grow.”

He rejected suggestions by Christine Lagarde, president of the International Monetary Fund and the former economics minister of France, that Germany should somehow become less competitive to give other countries a chance.

“The deficit countries must act,” Mr. Weidmann said. “They must address their structural weaknesses. They must become more competitive, and they must increase their exports.”

DealBook Column: Welcoming Higher Taxes in France, but Not That High

Christian Hartmann/ReutersPresident François Hollande of France.

PARIS — A little over a year ago, some of the most prominent and wealthy executives in France signed a petition seeking higher taxes on themselves. Yes, higher taxes.

“We are conscious of having benefited from a French system and a European environment that we are attached to and which we hope to help maintain,” wrote the group, which included the chief executives of Air France-KLM and Société Générale, and the billionaire heiress to the L’Oréal fortune, among others. “When the public finances deficit and the prospects of a worsening state debt threaten the future of France and Europe and when the government is asking everybody for solidarity, it seems necessary for us to contribute.”

You may know what happened next: François Hollande, the country’s socialist president, proposed a 75 percent marginal tax rate on all income over $1.3 million. (The highest marginal tax rate on the first $1.3 million would be 45 percent, up from 41 percent.) Marginal tax rates on capital gains would rise to as much as about 60 percent.

Now many of the nation’s wealthiest executives — including some who signed the original petition — and entrepreneurs, private equity managers and others who are millionaires, or want to become millionaires, are crying foul. In a sign that executives are moving, or threatening to move, to lower-taxed countries, high-end real estate in Paris is being thrown on the market.

Jean-Paul Agon, chairman and chief executive of L’Oréal, who signed the original petition, has been decrying the new tax rates, saying they are significantly higher than he expected and would damage the country’s economy. Stephane Richard, the chief executive of France Télécom, who also signed the petition, and François-Henri Pinault, the chairman and chief executive of PPR, which owns brands like Gucci and Yves Saint Laurent, sounded off against the tax, too.

Last week, Pierre Chappaz, a French entrepreneur, wrote online, “I do not know a single start-up founder who accept the idea that creating a company, in which it will invest all his savings and years of effort often without a salary, must then give to the State 60.5 percent of gain when he sells his company if he succeeds.” The statement went viral. An online group calling itself Les Pigeons — slang for sucker — has more than 63,000 “likes” on its Facebook page.

The private equity industry is similarly up in arms. The 60.5 percent rate would help perpetuate “the image of a country that does not like achievement and success, and that strikes a confiscatory tax,” an industry group said in a statement.

And then there is Bernard Arnault, the chief executive of LVMH, one of France’s wealthiest men. He recently said he was applying for citizenship in Belgium, setting off a firestorm, including a headline in the left-leaning newspaper, Liberation, that mildly translated as, “Get lost, you rich idiot!”

Mr. Arnault, who is suing the newspaper for “extreme vulgarity and the violence of the headline,” has insisted he is not leaving the country over the new tax regime. He said he would “fulfill my fiscal obligations” to France as a resident, saying that “Our country must count on everyone to do their bit to face a deep economic crisis amid strict budgetary constraints.”

Still, all the anger and angst appears to be pushing Mr. Hollande and his administration to back down, at least slightly. The 75 percent tax will now be effective for only the next two years. And last week, a budget minister, Jérôme Cahuzac, perhaps bowing to pressure from Les Pigeons, said the capital gains treatment on start-ups was “a mistake” and said the government would seek a remedy.

The purpose of the tax is more populist than mathematical: the marginal income tax increase is estimated to raise only about $300 million.

The debate in France raises an important question amid the election campaign in the United States about whether the wealthy should pay more — and by how much. The American billionaire Warren E. Buffett, like some of the French, called for higher taxes on the rich, but he never sought rates at the levels being discussed here in France.

Under President Obama’s proposed Buffett Rule, the wealthiest Americans would have paid no less than 30 percent of all income.

Marginal tax rates in the United States were as high as 94 percent during World War II in 1944 and 1945, but there were so many loopholes that few people paid anything close to that rate. For now, it is capped at 35 percent, unless the Bush tax cuts expire.

So where is the line?

The reality in Europe is that moving from Paris to London may not be that big of a deal, so extreme tax rates could be a deciding factor in where a person or business decides to locate.

But Thomas Piketty and Emmanuel Saez, two French economists who influenced Mr. Hollande, have said that the country’s economic growth won’t be hurt unless the marginal rates on the highest incomes exceed 83 percent.

The idea of soaking the rich is often a popular one. But if there is lesson in the French experience, despite the economic models, it is that there are limits.