Opinion writer
Former president George W. Bush sits with the spouses of African leaders at a Spousal Symposium at the Kennedy Center on Aug. 6, 2014. (Pete Marovich/Getty Images)

Bombarded by negative news stories (is there any other kind?) and a reprehensible presidential campaign, it is, to put it mildly, easy to lose perspective. Two data points should give us plenty of perspective — and cause for optimism.

First, Deirdre McCloskey writes:

Two centuries ago, the average world income per human (in present-day prices) was about $3 a day. It had been so since we lived in caves. Now it is $33 a day—which is Brazil’s current level and the level of the U.S. in 1940. Over the past 200 years, the average real income per person—including even such present-day tragedies as Chad and North Korea—has grown by a factor of 10. It is stunning. In countries that adopted trade and economic betterment wholeheartedly, like Japan, Sweden and the U.S., it is more like a factor of 30—even more stunning.

A second data point, not unrelated to the first, comes from the World Health Organization’s new report on longevity:

Life expectancy increased by 5 years between 2000 and 2015, the fastest increase since the 1960s. Those gains reverse declines during the 1990s, when life expectancy fell in Africa because of the AIDS epidemic and in Eastern Europe following the collapse of the Soviet Union. The increase was greatest in the African Region of WHO where life expectancy increased by 9.4 years to 60 years, driven mainly by improvements in child survival, progress in malaria control and expanded access to antiretrovirals for treatment of HIV. . . .

Global life expectancy for children born in 2015 was 71.4 years (73.8 years for females and 69.1 years for males), but an individual child’s outlook depends on where he or she is born. The report shows that newborns in 29 countries – all of them high-income — have an average life expectancy of 80 years or more, while newborns in 22 others – all of them in sub-Saharan Africa — have life expectancy of less than 60 years.

No one is saying poverty has been eradicated or that great challenges and inequality do not exist. (The bottom five countries in life expectancy are all in sub-Saharan Africa.) Shockingly, 5.9 million children still die before their fifth birthday, for example. Nevertheless, it helps to remember that the planet’s population on average has never been richer or lived longer.

McClosky posits that it is the success and spread of  ” ‘liberalism,’ in its original meaning of ‘worthy of a free person,’ ” that is responsible for this unprecedented explosion in wealth, which in turn can be put to good uses such as reducing child mortality. This is what the American Enterprise Institute’s Arthur Brooks calls the moral case for capitalism: It has helped bring a billion people out of poverty and is helping the world be healthier and, yes, happier. (It’s hard to be happy when weighed down by poverty and/or illness.)

We’d be remiss, however, if we did not acknowledge that wealth creation alone does not automatically result in healthier and richer people around the globe. It takes both public efforts such as George W. Bush’s President’s Emergency Plan For AIDS Relief, which has saved millions of lives, and private efforts such as those of the Gates Foundation, which invests in “vaccines to prevent infectious diseases—including HIV, polio, and malaria—and support[s] the development of integrated health solutions for family planning, nutrition, and maternal and child health.”

Small-L liberalism that helps produce wealth (for the United States as a whole and Bill and Melinda Gates personally) and values in support of human dignity underwrite the phenomenal advances we see. We should be wary of demagogues who would dismantle or severely hinder the economic system that creates such prosperity (yes, we are talking to you, Bernie Sanders) or who trash U.S. global leadership and small-D democratic values (as Donald Trump does). Perhaps if more people understood the historic gains made in just this past generation, they’d be less inclined to tear down the architecture that produced such progress.