Presidential hopeful people in the Democratic Primary have had a new litmus test in recent weeks: do they want to switch off private health insurance?

Sen Kamala Harris stood for a simple version of this question and gave a simple answer. "Let's remove all that," Harris said about private reporting.

Senator Cory Booker stood for a slightly more confusing version of this question and gave a slightly more confusing answer that meant support for keeping certain parts of the healthcare system private.

An international perspective is useful here. When you look at the rest of the world – in the dozens of countries managing universal healthcare systems – you notice that every universal health plan relies on private insurance in one form or another.

"In principle, every country with universal coverage also has private insurance," says Gerard Anderson, a professor at Johns Hopkins University who studies international healthcare systems. "I do not think there is a model in the world that you can do without."

Other developed countries routinely use private insurance to fill in the gaps in their public plans or to provide patients with a way to reach a doctor faster. Some countries, such as Australia, even take aggressive steps, such as offering tax benefits to encourage citizens to register for private coverage alongside their public plan.

"Every country has its own role for private insurance," said Robin Osborn, vice president of the non-profit Commonwealth Fund, which studies international health systems. "In almost every system it is usually not controversial, because the commitment to universal basic coverage is there."

How other countries use private health insurance, it turns out, you can actually tell a lot about what countries find important in a healthcare system – and how they think access to care should be organized.

The three ways in which other countries use private health insurance

When you look at our countries, you actually see them using the coverage of private health care in three different ways.

First, there are some countries that require all citizens to sign up for health insurance that is managed by private insurers. These insurers usually compete in a market with strict rules about what they have to cover and how many different medical services cost.

The Netherlands and Israel are good examples of this type of systems. In both countries, citizens are obliged to purchase cover from a private plan. Somewhat coincidentally, the Netherlands and Israel both have four dominant health plans on their private markets.

In both cases, insurers must cover the same set of benefits and not charge higher sickness premiums. But they can compete on other dimensions.

"They compete on what other benefits they offer, and the price of the premium too," says Osborn. "In general, however, people do not change insurance much, they tend to stick to their plans for a long time, even though they have the opportunity to change every year."

The advantage that these systems offer is mainly related to the choice: in Israel and the Netherlands, patients have multiple options for looking for health insurance.

Secondly, there are some countries where private insurance supplements a public insurance policy. It is quite common for Canadians and Europeans to take out additional insurance policies that relate to things that the public plan will not do.

Sometimes this takes the form of additional insurance to pay for unsecured benefits. In Canada, for example, two thirds of the population makes private plans to cover the benefits in terms of vision, teeth and prescription drugs – none of which are included in the public plan. Thirty-nine percent of Danish citizens have private coverage for unsecured benefits, including physical therapy.

In other places this takes the form of additional insurance to cover the cost sharing that is included in the public plan. If you look at France, you can see that 95 percent of the population take out private insurance (or get government subsidies) to cover their copayments and deductibles.

Thirdly, there are a few countries where private insurance policies are complementary to public insurance. In these places, residents buy private cover to get better, faster access to benefits to be fall under the public system.

Osborn points to England as a particularly good example of this type of coverage. Approximately 11 percent of the British population buys additional cover that can give them faster access to specialized doctors or elective procedures.

"The UK attaches great importance to solidarity and equality in its health system, but at the same time they are still very comfortable with this private insurance role," she says. "I think it works like a safety valve, people use it for elective surgery, for something like a hip replacement where there is a long waiting list."

Australia is another example of a country that does really embraced additional coverage, to the point that 47 percent of the nation's residents carry private cover alongside their public plans. The government even encourages citizens to buy a private plan, offer tax credits to those who register – and a lower lifelong premium for those who sign up before their thirtieth.

Many countries also combine these different types of private insurance. In the Netherlands, for example, private plans use the basic benefits package – and 84 percent of Dutch residents buy a supplementary supplementary plan to cover more benefits. Denmark has strong markets for both additional and additional coverage, just like New Zealand and Australia.

Why do we have a debate about eliminating private coverage in the United States?

The debate we now have about universal coverage in the United States is now often concentrated on the care plan of Sen. Bernie Sanders (I-VT). His plan – that you can read a longer interpreter here – provides a government-managed health insurance that covers a wide range of benefits, including facial, dental and prescription drugs. His plan has no cost sharing for patients – which means that you do not pay an additional payment when you go to the doctor, nor do you have a deductible to save before your benefits begin.

The Sanders plan allows additional private insurance, the type that covers matters that are not covered by the public system. But because the public insurance plan covers virtually everything, it is difficult to see what role it would play.

Here is the problem: none of our countries have built such a health care system. Canada, France, England, Australia, the Netherlands – they all have health insurance systems with a funding deficit.

None of our countries has found a way to provide health care that covers all benefits for patients at no cost – the price is simply unaffordable. Instead, most offer free or cheap access to basic medical services, while patients are asked to use something for the parts that the government can not afford.

If you look at our colleagues, the main question does not seem to be or there is a private health insurance policy. The main question seems to be instead which role private health insurance. The answer to that question can often reflect the core values ​​of a health system.

Take Canada, for example. That country prohibits additional insurance. Any benefit covered by the public system – such as doctor's visits and hospital stays – can not be covered by a private provider there.

This reflects the commitment of the Canadian system for equality and fairness. As a scholar there memorably told the journalist T.R. Reid, Canadians do not mind waiting in rows, as long as rich Canadians and poor Canadians wait about the same amount. & # 39;

This is really different from the Australian system, where the government explicitly encourages citizens to register for private coverage with different tax deductions and fines. There, civil servants think they can alleviate the burden on the public system by building a robust private system in parallel.

It is true that Australians value their health care more than Canadians like theirs, but it is also true that the more well-to-do Australians take part in private insurance more often than Australians with lower incomes, thus introducing an element of inequality that does not exist in Canada. The health system that you prefer sets the values ​​you hold.

"I think there are some fundamental policy issues that countries have to deal with," Anderson says. "Should private insurance allow you to jump in line, you have to have a private room, these are big policy debates in other countries."