Researchers are warning that millions of people around the world aren’t being counted in census and survey data, leaving policymakers in the dark about the populations they govern.

They say a ‘quiet crisis’ is unfolding with census data due to declining response rates and concerns about the accuracy of the data.

Plastic bag regulations – bans and consumer fees – have led to meaningful reductions in plastic litter on U.S. shorelines, according to a new study. Plastic pollution has become a pervasive environmental issue; plastic debris comprises most of the marine litter worldwide and has been shown to pose serious threats to ocean life, ecosystems, and coastal economies.  Much of this pollution originates from land and enters the ocean via rivers, wastewater, or wind. Among the most problematic items entering marine systems are single-use plastic shopping bags, which has prompted the implementation of a variety of policies – ranging from fees to outright bans – to curb this pollution. Although these policies are being increasingly used worldwide, their effectiveness in reducing plastic waste in the environment remains unknown. To address this gap, Anna Papp and Kimberly Oremus evaluated the effects of plastic bag bans and fees in the United States on the prevalence of plastic bag litter on shorelines. Papp and Oremus analyzed crowdsourced data from more than 45,067 U.S. shoreline cleanups alongside 611 local and state-level plastic bag regulations enacted between 2017 and 2023. By applying robust causal inference methods, the authors found that plastic bag policies led to a 25–47% reduction in the proportion of plastic bags among total litter collected during cleanups compared to locations without such regulations. According to the findings, policies involving consumer fees potentially have the largest impact on reducing litter. While complete bag bans also reduced litter, partial bans, which often allow exceptions for thicker “reusable” bags, appeared to be the least effective. Moreover, the largest reductions in plastic litter occurred in places that had the highest baseline levels of plastic bag pollution, suggesting that these policies are most effective where the problem is most severe. Papp and Oremus also suggest that plastic bag policies may reduce wildlife entanglement by 30 to 37%, though they note that these estimates are imprecise due to data limitations.

A segment of Science's weekly podcast with Anna Papp, related to this research, will be available on the Science.org podcast landing page after the embargo lifts. Reporters are free to make use of the segments for broadcast purposes and/or quote from them – with appropriate attribution (i.e., cite "Science podcast"). Please note that the file itself should not be posted to any other Web site.

‘Starter packs’—curated user lists that new users can follow with a single click—played a key role in helping Bluesky grow to over 30 million users, according to a new study.

Researchers have validated a technique for studying how people make “moral” decisions when driving, with the goal of using the resulting data to train the artificial intelligence used in autonomous vehicles. These moral psychology experiments were tested using the most critical audience researchers could think of: philosophers.

Democracy is in danger. Two out of three people worldwide currently live in an autocracy; 20 years ago, it was only one in two. Even in traditionally stable democracies such as the US, institutions are being weakened, norms violated, and freedoms massively eroded. Now science is also coming under pressure. That is why researchers from a wide range of disciplines, led by Potsdam cognitive scientist Prof. Dr. Stephan Lewandowsky, have published a handbook in response to the global resurgence of autocracy. With their “Anti-Autocracy Handbook,” they aim to provide scientists and civil society actors with tools to understand the causes of this change and counteract it.

Higher levels of wellbeing may help reduce the risk of memory loss in middle age, suggests new research, which tracked more than 10,000 over 50-year-olds across a 16-year span.

Having poor access to food, living in a disadvantaged neighborhood and not having strong friend and family support may lead to worse outcomes after stroke, according to a study published on June 18, 2025, online in Neurology^® Clinical Practice, an official journal of the American Academy of Neurology. Conversely, the study found that people with these negative social factors had better survival rates after stroke. The study does not prove that socioeconomic factors lead to worse outcomes and better survival from stroke; it only shows an association.