“The world my father told me about 50 years ago was a divided world,” says Hans Rosling, famed Swedish statistician and development expert, in a new video. Standing in the middle of one of his trademark graphs of development indicators, his body neatly splitting the data, he gestures: “In many people’s minds, the world still looks like this: developing and developed.”

“But it’s a myth,” he continues, “because the world has improved immensely in the last 50 years.”

Using Trendalyzer, software he and his colleagues at Gapminder developed to make data more visually appealing and comprehensible, Rosling plots total fertility and child mortality rates on a set of axes and sets the data in motion, showing how both indicators have declined since the early 1960s. “Year after year, child mortality fell in almost all countries,” he explains. “And as child mortality fell, women chose to have fewer and fewer babies.”

The video was launched to coincide with Bill Gates’ 2013 annual letter, which focuses on the need for improved measuring capabilities in development programs. Rosling’s emphasis on fertility and child mortality rates also reflects the recent resurgence of family planning on the development agenda, which the Bill and Melinda Gates Foundation has made a priority since spearheading the London Summit on Family Planning last year.

Rosling’s renowned gift for statistical presentation is an obvious match for Gates’ message. While conventional narratives of developing and developed nations remain firmly entrenched throughout much of the world, statistics paint a more nuanced and even optimistic picture.

To underscore this point, and to further highlight the need for improved measuring capabilities, Rosling highlights the case of Ethiopia, which has made tremendous progress in lowering both child mortality and total fertility rates since 1990. He cites “improved access to health service in rural areas and well-spent aid” for the precipitous decline in child mortality, which fell from a high of 23 percent to just under 8 percent in slightly more than a quarter century. Rosling also notes that “better access to family planning” has lowered the number of babies per woman from seven to around four during this same span.

Women and their children having access to more health services is certainly good news, but even this masks some wrinkles in the statistics. In Ethiopia, as in many other developing nations, there is a significant rural-urban split. “The capital, Addis Ababa, is already down here,” Rosling says, pointing to dramatically lowered fertility and child mortality rates. “But the remote Somali region still has high child mortality” and fertility rates.

Ethiopia’s large home-grown network of population, health, and environment (PHE) projects – which combine reproductive health and sustainable livelihood interventions – has made reaching the country’s rural areas a priority. And the combination of these elements into a synergized and holistic development approach has produced significant results, both in Ethiopia and elsewhere.

However, it has been difficult to accurately measure the impact that PHE programs have had. This is partly due to a lack of financing and evaluation capacity within the implementing organizations, but it’s also true that some organizations simply haven’t placed a high premium on accurate quantitative measurement and evaluation.

Neglecting data collection is a mistake, according to Rosling. “We must measure the progress of countries” to ensure that development goals are reached, he says. “It’s only by measuring, that we can cross the river of myths.”

Sources: Bill and Melinda Gates Foundation, Gapminder Foundation, World Bank.

Video Credit: “The River of Myths by Hans Rosling,” courtesy of the Bill and Melinda Gates Foundation; Chart: World Bank.