If you owned a business that employed low wage workers, would you increase the minimum wage you paid from $7.25 to $10.10 an hour? Should the federal government increase the minimum wage to $10.10 an hour?

President Obama on Monday renewed his call to raise the federal minimum wage and to protect the right to equal pay for women as the midterm elections come into sight.

In spite of opposition from Republicans, Mr. Obama said, addressing a crowd of about 6,000 people gathered in Milwaukee at a festival hosted by the local A.F.L.-C.I.O., his goal is to make sure all Americans can meet simple goals, like being able to pay their bills and send their children to school.

“There is no denying the simple truth: America deserves a raise,” he said.

Hailing examples set by employers like Kentucky State University, whose president took a pay cut to give raises to his lowest-paid workers, Mr. Obama said Congress needed to catch up to the businesses and other institutions — as well as 13 states and the District of Columbia — that have already acted to raise their minimum wage.

Mr. Obama also referred to his executive order in February requiring that federal contractors in 2015 increase their minimum hourly wage to $10.10 from $7.25.

Countering arguments that raising the minimum wage would reduce jobs, Mr. Obama said states that had not waited for the federal government to raise their wages had seen more job growth than those that had not raised their wages.

During his brief stop — he was in Milwaukee for about two hours — Mr. Obama expressed optimism about the nation’s economic recovery, emphasizing the progress made since the 2008 collapse, which happened about two weeks after he first spoke at this labor festival as a presidential candidate. He highlighted that nearly 10 million jobs have been added in the last four and a half years, and that the unemployment rate has been improving.

“By almost every measure, the American economy and American workers are better off than when I took office,” Mr. Obama said.

After a summer dominated by grim news at home and abroad, the president on Monday, the unofficial opening of the general election season, tried to refocus attention on an economic policy issue that could help his party. Democrats, wary of getting too close to Mr. Obama and his lackluster approval ratings, are fighting to keep control of the Senate in the midterm elections.

The president urged Americans not to listen to those who would have them believe that voting would not do them any good.

“Don’t buy it, because despite the cynics, America’s on the move,” he said. “It’s making progress.”

Accompanied by Thomas E. Perez, the labor secretary, and a handful of labor leaders who included Mary Kay Henry, the president of the Service Employees International Union, Mr. Obama praised American workers for banding together over the past century to achieve gains like the 40-hour workweek.

Wisconsin has been a battleground for labor unions in recent years. In July, the Wisconsin Supreme Court upheld a law limiting the collective bargaining rights of public workers, a measure that drew thousands to the State Capitol in protest in 2011.

On Monday, Gov. Scott Walker, the Republican who proposed the law, greeted Mr. Obama when he landed in Milwaukee.

Mr. Obama previewed his remarks in his weekly address on Saturday, saying that raising the minimum wage was “one of the best ways to give a boost to working families.”

“The bottom line is, America deserves a raise,” he said. “But until we’ve got a Congress that cares about raising working folks’ wages, it’s up to the rest of us to make it happen.”

What would you do if you were a new manager and you realized that some employees were working 70 hours a week and never paid a time-and-half overtime for more than 40 hours work a week? If you were a FedEx executive, would you categorize your couriers as independent contractors to avoid paying them overtime and other benefits?

Week after week, Guadalupe Rangel worked seven days straight, sometimes 11 hours a day, unloading dining room sets, trampolines, television stands and other imports from Asia that would soon be shipped to Walmart stores.

Even though he often clocked 70 hours a week at the Schneider warehouse here, he was never paid time-and-a-half overtime, he said. And now, having joined a lawsuit involving hundreds of warehouse workers, Mr. Rangel stands to receive more than $20,000 in back pay as part of a recent $21 million legal settlement with Schneider, a national trucking company.

“Sometimes I’d work 60, even 90 days in a row,” said Mr. Rangel, a soft-spoken immigrant from Mexico. “They never paid overtime.”

The lawsuit is part of a flood of recent cases — brought in California and across the nation — that accuse employers of violating minimum wage and overtime laws, erasing work hours and wrongfully taking employees’ tips. Worker advocates call these practices “wage theft,” insisting it has become far too prevalent.

Some federal and state officials agree. They assert that more companies are violating wage laws than ever before, pointing to the record number of enforcement actions they have pursued. They complain that more employers — perhaps motivated by fierce competition or a desire for higher profits — are flouting wage laws.

Many business groups counter that government officials have drummed up a flurry of wage enforcement actions, largely to score points with union allies. If anything, employers have become more scrupulous in complying with wage laws, the groups say, in response to the much publicized lawsuits about so-called off-the-clock work that were filed against Walmart and other large companies a decade ago.

Here in California, a federal appeals court ruled last week that FedEx had in effect committed wage theft by insisting that its drivers were independent contractors rather than employees. FedEx orders many drivers to work 10 hours a day, but does not pay them overtime, which is required only for employees. FedEx said it planned to appeal.

Julie Su, the state labor commissioner, recently ordered a janitorial company in Fremont to pay $332,675 in back pay and penalties to 41 workers who cleaned 17 supermarkets. She found that the company forced employees to sign blank time sheets, which it then used to record inaccurate, minimal hours of work.

David Weil, the director of the federal Labor Department’s wage and hour division, says wage theft is surging because of underlying changes in the nation’s business structure. The increased use of franchise operators, subcontractors and temp agencies leads to more employers being squeezed on costs and more cutting corners, he said. A result, he added, is that the companies on top can deny any knowledge of wage violations.

“We have a change in the structure of work that is then compounded by a falling level of what is viewed as acceptable in the workplace in terms of how you treat people and how you regard the law,” Mr. Weil said.

His agency has uncovered nearly $1 billion in illegally unpaid wages since 2010. He noted that the victimized workers were disproportionately immigrants.

Guadalupe Salazar, a cashier at a McDonald’s in Oakland, complained that her paychecks repeatedly missed a few hours of work time and overtime pay. Frustrated about this, she has joined one of seven lawsuits against McDonald’s and several of its franchise operators, asserting that workers were cheated out of overtime, had hours erased from timecards and had to work off the clock.

“Basically every time that I worked overtime, it didn’t show up in my paycheck,” Ms. Salazar said. “This is time that I would rather be with my family, and they just take it away.”

Business advocates see a hidden agenda in these lawsuits. For example, the lawsuit against Schneider — which owns a gigantic warehouse here that serves Walmart exclusively — coincides with unions pressuring Walmart to raise wages. The lawyers and labor groups behind the lawsuit have sought to hold Walmart jointly liable in the case.

Walmart says that it seeks to ensure that its contractors comply with all laws, and that it was not responsible for Schneider’s employment practices. Schneider said it “manages its operations with integrity,” noting that it had hired various subcontractors to oversee the loading and unloading crews.

Business groups note that the lawsuits against McDonald’s have been coordinated with the fast-food workers’ movement demanding a $15 wage. “This is a classic special-interest campaign by labor unions,” said Stephen J. Caldeira, president of the International Franchise Association. In legal papers, McDonald’s denied any liability in Ms. Salazar’s case, and the Oakland franchisee insisted that Ms. Salazar had failed to establish illegal actions by the restaurant.

Lee Schreter, co-chairwoman of the wage and hour practice group at Littler Mendelson, a law firm that represents employers, said wage theft was not increasing, adding that many companies had become more vigilant about compliance. But that has not stopped lawyers from bringing wage theft complaints because of the potential payoff, Ms. Schreter said. “These are opportunistic lawsuits,” she said.

Michael Rubin, one of the lawyers who sued Schneider, disagreed, saying there are many sound wage claims. “The reason there is so much wage theft is many employers think there is little chance of getting caught,” he said.

Commissioner Su of California said wage theft harmed not just low-wage workers. “My agency has found more wages being stolen from workers in California than any time in history,” she said. “This has spread to multiple industries across many sectors. It’s affected not just minimum-wage workers, but also middle-class workers.”

Many other states are seeing wage-theft cases. New York’s attorney general, Eric T. Schneiderman, has recovered $17 million in wage claims over the past three years. “I’m amazed at how petty and abusive some of these practices are,” he said. “Cutting corners is increasingly seen as a sign of libertarianism rather than the theft that it really is.”

In Nashville last February, nine housekeepers protested outside a DoubleTree hotel because the subcontractor that employed them had failed to pay a month’s wages. “The contractor said they didn’t have the money, that the hotel hadn’t paid them,” said Natalia Polvadera, a housekeeper. “We went to the hotel manager — he showed receipts that they had paid the contractor.”

Nonetheless, the protests persuaded DoubleTree to pay the $12,000 in wages owed.

Mr. Weil said some executives had urged him to increase enforcement because they dislike being underbid by unscrupulous employers.

His agency has begun cracking down on retaliation against workers who complain, suing a Texas company that fired a janitor when he refused to sign a statement that falsely said he had already received back wages due him from a Labor Department investigation.

“This is just not acceptable,” Mr. Weil said. “You can’t threaten people to lose their jobs because they are asserting rights that go back 75 years.”

If you were a NBC news executive, would you hire a former president’s daughter, with little journalism experience, as a journalist with a $600,000 annual salary? How would you manage other experienced reporters earning less who may be very envious?

Less than three years after she embarked on a new and lucrative career as an NBC News special correspondent, Chelsea Clinton said on Friday that she would leave that position.

In a letter posted on her Facebook page, Ms. Clinton said she had decided to depart NBC News to focus on philanthropic work at the Bill, Hillary & Chelsea Clinton Foundation. She and her husband, Marc Mezvinsky, are also expecting their first child this fall. At the same time, her mother, Hillary Rodham Clinton, is mulling a presidential bid in 2016.

“I am profoundly grateful to NBC viewers who responded to the stories I shared,” wrote Ms. Clinton, whose reports were part of NBC News’s “Making a Difference” series. Those reports were often in line with the charitable work Ms. Clinton does at the Clinton Foundation.

Ms. Clinton’s tenure at the news outlet was not a smooth one, less because of her feel-good reports than because a media-shy first daughter was hired as a television journalist earning a six-figure salary. (In 2009, NBC News hired Jenna Bush Hager, a daughter of former President George W. Bush, as a special correspondent for the “Today” show, drawing similar criticism.)

Ms. Clinton, who is vice chairwoman of the philanthropic organization her father founded, made an annual salary of $600,000 at NBC, according to Politico. She remains on the board of IAC/InterActiveCorp, the digital media company overseen by Barry Diller, a longtime Clinton supporter. In 2011, that position paid an annual retainer of $50,000 and a $250,000 grant of restricted stock.

More recently, Ms. Clinton’s affiliation with NBC News had been seen as a potential conflict as her mother embarked on a nationwide book tour that looked like the precursor to a presidential campaign. It was during Hillary Clinton’s hard-fought 2008 Democratic primary against then Senator Barack Obama that her daughter emerged as a more public figure, stumping for her mother.

While Chelsea Clinton’s NBC segments did not attract particularly large audiences, news executives and her subjects said her celebrity brought outsize attention to the communities and nonprofits she profiled. “It’s hard to get stories like this told on a platform as big as ‘NBC Nightly News,’ “ said Josh Wachs, chief strategy officer at Share Our Strength, a nonprofit that fights childhood hunger.

A number of media outlets talked to Ms. Clinton before she decided to sign with NBC News in December 2011. Since then the network has experienced a management shift; Deborah Turness, a British news executive, recently stepped in as president. Not long ago, Ms. Clinton switched to a contract that allowed her to exit.

In a statement, Alex Wallace, senior vice president of NBC News, said, “While she will be missed, we look forward to working with her in the future.”

If you were an executive of a U.S.-based company, would you acquire a firm overseas and reincorporate there to avoid paying U.S. taxes? Is that ethical?

A pharmaceutical company moved its headquarters to Ireland, sharply reducing its tax rate. A billboard company reclassified itself as a real estate concern, meaning it will no longer pay corporate taxes. And a big oil producer split itself in two, cleaving off a multibillion-dollar division that now operates tax-free.

Across corporate America, companies large and small are finding new ways to address one of the business world’s oldest irritations: paying taxes.

By exploiting existing loopholes and devising new ones, some of the country’s best-known companies are making it harder than ever for the federal government to replenish its already depleted coffers.

As a result, business income tax revenue remains stagnant at about 2 percent of gross domestic product even as corporate profits hit records.

Business taxes now make up less than 10 percent of federal revenue, and in some years as little as 6.6 percent. That is sharply down from the years after World War II, when about 30 percent of federal revenue came from corporate taxes.

The decline is the result of the rise of untraditional business structures, the effects of a more globalized economy and a labyrinth of subsidies and tax credits. And though the erosion has happened gradually over decades, the surging popularity of inversions — acquisitions of overseas companies that allow American corporations to reincorporate abroad — is raising concerns that an already precarious situation is growing untenable.

“There’s been a long, slow, steady decline,” said William G. Gale, co-director of the Urban-Brookings Tax Policy Center and an economic adviser to President George H. W. Bush. “It’s a confluence of a bunch of things, and it’s increasingly difficult to figure out how to effectively tax corporations.”

Lawmakers in Washington are calling for an overhaul of the corporate tax code. Upon becoming chairman of the Senate Finance Committee this year, Senator Ron Wyden, Democrat of Oregon, said it was time to revamp the “dysfunctional, rotting mess of a carcass that we call the tax code.” But political gridlock makes the possibility of any quick action all but nonexistent.

While officials may not be in the mood to cooperate, they are taking notice of recent developments. Three tax-avoidance tactics in particular have grabbed the attention of lawmakers and the White House, though the root of the problem runs much deeper.

Most prominently, the number of inversions is at an all-time high, fueled by a rush of health care companies striking deals for overseas rivals.

AbbVie, which will become one of the 50 largest companies in the world through its $54 billion takeover of the Irish drug maker Shire, became the largest American company to strike an inversion. But more than a dozen other firms have made similar moves, most likely costing the government nearly $20 billion over the next 10 years, according to the Joint Committee on Taxation.

Republicans and Democrats have called for legislation to end inversions, even in the absence of broader corporate tax reform. But the threat of new laws to curb them only seems to be quickening the pace.

“Wall Street is whispering in the ears of all these corporate executives saying, ‘Congress might shut this down, you’ve got to do it now,’ ” said Rebecca J. Wilkins, senior counsel at the Institute on Taxation and Economic Policy.

Another corporate structure being exploited now more than ever is the master limited partnership. These partnerships are part of a broad class of companies known as pass-through entities because they pass all profits along to shareholders and are therefore exempt from paying corporate income taxes.

Dozens of these have been created in the last two years, reducing the Treasury’s income by about $1.6 billion annually, according to the Joint Committee on Taxation. Last year, the oil and gas company Phillips 66 spun out its pipeline assets into a master limited partnership, shielding millions of dollars in profits from taxation.

In response to the uptick in master limited partnerships, the Internal Revenue Service temporarily halted new approvals of the structure this year, and the Treasury Department said it was examining the effects on future tax revenue.

Another type of pass-through entity, the real estate investment trust, is also experiencing record popularity. Like master limited partnerships, real estate investment trusts pass profits along to investors, exempting them from corporate taxes.

But loose standards have allowed an ever wider variety of businesses to reclassify themselves as real estate investment trusts, broadening the universe of businesses avoiding taxes altogether. CBS Outdoor, the billboard company, relisted as a REIT this year.

And in a recent ruling, the I.R.S. allowed Windstream, a telecommunications firm, to spin off its underground cables and assorted real estate into a separate publicly traded company. Tax experts believe the ruling opens the door for a new wave of such transactions from a broad range of businesses.

Corporate advisers say that companies are pursuing these structures because, in the face of slow organic growth, executives are looking for additional profits wherever they can find them.

“It’s self-help tax reform,” said Kyle E. Pomerleau, an economist at the Tax Foundation. “If Congress is not willing to reform the corporate tax code, companies are going to do it for themselves.”

Despite the outsize attention in Washington being paid to the tax-avoidance techniques, they represent only a small part of the reason corporate tax revenue has declined so precipitously.

“Inversions are the very small end of the tail,” Mr. Gale said. “They just happen to be the part that’s wagging right now.”

The more fundamental issue is a series of systemic changes to the tax system and the shifting international tax landscape.

Over the years, a growing portion of the United States economy has shifted away from traditional corporations and into lower-taxed structures like partnerships and S-corporations, which are exempt from paying income taxes. This has put a growing swath of the economy beyond the reach of the I.R.S.

“It’s gotten much easier to never put money into the corporate sector, or to move it around internationally once it is in the corporate sector,” Mr. Gale said.

Only 6 percent of businesses are traditional corporations subject to the corporate income tax, according to the Congressional Research Service. That is down from 17 percent in 1980. The result is that less than half of the government’s business income comes from corporations, down from about 80 percent in 1980.

And while most S-corporations are small to midsize businesses, as was intended, some of the country’s largest private companies, including Bechtel, one of the country’s largest engineering firms, are also organized as S-corporations to avoid corporate income taxes.

“A lot of the income that used to be earned at the corporate level is now being moved to the S-corp level,” Mr. Pomerleau said.

And for those traditional corporations that are subject to the United States corporate tax rate, which at 35 percent is the highest in the world, there are myriad ways to avoid paying anything close to that. By taking advantage of a warren of credits, deductions and exemptions, corporations pay an average effective rate of just 12.6 percent, according to the Government Accountability Office.

Much of the tax avoidance comes as multinational corporations take advantage of overseas subsidiaries to shuffle money, intellectual property and assets into lower-taxed jurisdictions. In 2010, a majority of overseas profits reported by American firms were recorded in just 12 low-tax countries like the Netherlands, Bermuda, and Ireland, according to Citizens for Tax Justice.

That skewed distribution of profits is a result of the changed global tax landscape, where many countries have sharply lowered their corporate rates while the United States has not.

Those attractive overseas rates — and the fact that, unlike the United States, other countries do not tax international earnings — are among the reasons that companies are rushing to strike inversion deals.

“We cannot compete with zero,” Ms. Wilkins said.

Republicans and Democrats in Congress and the White House all agree the country is overdue for comprehensive tax reform. The last big revision of the tax code came in 1986. Before that, the previous rewrite was in 1954. But ideas on how to proceed vary wildly, diminishing the likelihood of any rapid reforms.

“There’s no primitive law of nature that every 30 years they will revise the tax code,” Mr. Gale said. “I don’t see much in terms of comprehensive tax reform happening with this Congress and this administration. It feels like they’re done talking to one another.”