This argument, often trumpeted by skeptics of vaccines, causes consternation among public-health experts who say misinformation is dissuading parents from inoculating their children against dangerous diseases.
Stein has been attracting more attention since the Democratic National Convention amid concerns that some supporters of former presidential candidate Bernie Sanders will defect from the party and vote for her. They are conveying their dissatisfaction on Twitter with the hashtag #JillNotHill.
Stein's poll numbers give her no chance of becoming president but are notable for a third-party candidate. The latest CNN/ORC poll puts Stein at 5 percent of the vote. The other leading third-party candidate, Libertarian nominee Gary Johnson, polled at 9 percent.
Stein and Sanders do agree on some issues where he and Clinton have differences of opinion, such as Wall Street reform and single-payer health care.
Here's a quick look at what Stein stands for.
Stein opposes fossil fuels and nuclear energy, and her platform calls for a U.S. economy that relies exclusively on renewable energy by 2030. She would levy a tax on emissions of carbon dioxide and other greenhouse gases and eliminate subsidies for the fossil-fuel and nuclear industries.
Stein is skeptical of the Food and Drug Administration and other regulatory agencies that are responsible for vetting agricultural and pharmaceutical products. She believes that lobbyists have too much sway over these decisions, as she explained in her interview on vaccines.
She is especially skeptical of genetically modified organisms. Her platform calls for a moratorium on GMOs in foods "until they are proven safe."
A recent report published by the European Union reviewed dozens of studies of genetically modified organisms and concluded they were no more dangerous than conventionally bred strains. The American Association for the Advancement of Science agrees, and opposes labeling genetically modified products because labels could cause false alarm.
Still, there has been political support for such labels. Last week, President Obama signed the first federal law requiring labels of genetically modified ingredients.
Stein believes the government should provide a job to anyone who can't get one in the private sector but who is willing to work. In Stein's vision, employment would be "an enforceable right," presumably meaning workers could sue the government if it did not provide them a job.
The idea of providing work for the unemployed directly through the government has been around at least since the New Deal. Today, though, most liberal policymakers are focused on education and training to make sure that workers are qualified for employment in the private sector and on managing interest rates so that payrolls expand.
Stein would repeal the Taft-Hartley Act, the federal law that allows states to bar unions from demanding that employers hire only workers who are members. Experts on labor say these right-to-work rules are an important part of the reason that union membership has declined.
In addition to guaranteeing work, Stein would establish a federal minimum wage of $15 an hour and guarantee a minimum income for all Americans. This guarantee would include those who cannot work because they are sick, disabled, or caring for children or other loved ones.
Stein also argues for making child care free for all parents. By contrast, Clinton has set the more modest goal of limiting child-care expenses to 10 percent of any family's income.
Like Sanders, the former presidential candidate and senator from Vermont, Stein supports a "Medicare-for-All" system, in which the federal government reimburses hospitals and doctors for all their services, eliminating the private health insurance industry. "Eliminate the cancer of health insurance," her platform reads.
Analysts generally panned Sanders's health-care proposal, saying it would force the government to borrow trillions of dollars to cover Americans' medical expenses. Similar single-payer systems in other countries typically place restrictions on the treatments and services that are covered to keep costs in check, which Sanders's plan did not.
Budgetary experts have not studied Jill Stein's proposals. On one hand, a tax on carbon dioxide would bring in more money for the federal government. On the other, a single-payer health-care system, universal free child care and an employment guarantee would be costly.
One potential source of revenue is Stein's proposal to radically reform the financial sector.
Her platform calls for barring Wall Street from "creating money" — something banks do all the time when they make more loans than they have in cash.
Critics have come up with a few ways of altering this fundamental feature of the banking system, and Stein's platform does not go into details. However, one benefit of these proposals is that they can effectively give the government much more money to spend. Since the government alone would create new money, Congress and the president would be able to decide how to spend it, rather than private borrowers who spend the new money banks create under the current system.
Stein also supports reinstating the Glass-Steagall Act, which prevented ordinary, Main Street commercial banks form placing riskier and more lucrative bets on Wall Street. On this point, she has more in common with Republicans, whose platform also calls for restoring the law, than with Democrats. Although Sanders and some other Democrats support reinstating Glass-Steagall, Clinton does not.
The Pentagon's budget would be another source of savings that could help fund Stein's programs. She proposes reducing military spending by 50 percent and closing the military's bases overseas.
Stein would remove U.S. nuclear arms from Turkey and several European countries, ground U.S. drones, and end foreign aid to certain allies such as Egypt, Saudi Arabia and Israel. She thinks the United States should rely mainly on the National Guard for defense.
Again, with regard to the military, Stein has more in common with Republican nominee Donald Trump than with Clinton. Trump has also proposed drastically curtailing American involvement in international conflicts — although at times, Trump has also called for U.S. airstrikes in a number of unstable countries.
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