Fears that this is resulting in some questionable findings began to emerge in 2005, when Dr. John P. A. Ioannidis, a kind of meta-scientist who researches research, wrote a paper pointedly titled “Why Most Published Research Findings Are False.”

Given the desire for ambitious scientists to break from the pack with a striking new finding, Dr. Ioannidis reasoned, many hypotheses already start with a high chance of being wrong. Otherwise proving them right would not be so difficult and surprising — and supportive of a scientist’s career. Taking into account the human tendency to see what we want to see, unconscious bias is inevitable. Without any ill intent, a scientist may be nudged toward interpreting the data so it supports the hypothesis, even if just barely.

The effect is amplified by competition for a shrinking pool of grant money and also by the design of so many experiments — with small sample sizes (cells in a lab dish or people in an epidemiological pool) and weak standards for what passes as statistically significant. That makes it all the easier to fool oneself.

... C. Glenn Begley, who is chief scientific officer at TetraLogic Pharmaceuticals, described an experience he had while at Amgen, another drug company. He and his colleagues could not replicate 47 of 53 landmark papers about cancer. Some of the results could not be reproduced even with the help of the original scientists working in their own labs.

Venezuela has the world’s cheapest gasoline, about six cents a gallon, a price so low that drivers often fill their tanks for less than a dollar and tip the gas station attendant more than the cost of the fuel pumped into their cars.

Despite the socialist orientation of Venezuela’s government, the wealthy and middle class benefit greatly from the fuel subsidy because they are more likely to have a car, while the poor primarily benefit through the effect on mass transportation fares. Two researchers at the Harvard Kennedy School, José Ramón Morales and Douglas Barrios, calculated that the value of the gasoline subsidy for the top 10 percent of households in 2010 was about $3,755 a year, compared with $506 a year for the bottom 10 percent.

Nations have so dragged their feet in battling climate change that the situation has grown critical and the risk of severe economic disruption is rising, according to a draft United Nations report. Another 15 years of failure to limit carbon emissions could make the problem virtually impossible to solve with current technologies, experts found.

Delay would likely force future generations to develop the ability to suck greenhouse gases out of the atmosphere and store them underground to preserve the livability of the planet, the report found. But it is not clear whether such technologies will ever exist at the necessary scale, and even if they do, the approach would likely be wildly expensive compared with taking steps now to slow emissions.