Metrics and Mechanisms: Measuring the Unmeasurable in the Science of Science

How does science work? What are its core mechanisms? In recent decades, research has increasingly explored such questions using a variety of quantitative metrics which can be easily calculated from publications. But some of these can be deceiving. Read more

Ranking earthquake forecasts using proper scoring rules: Binary events in a low probability environment

Probabilistic earthquake forecasts can be used to estimate the chance of future earthquake hazards, or to model important risk quantities including the number of fatalities, damaged elements of infrastructure or economic losses. The Collaboratory for the Study of Earthquake Predictability (CSEP) is a global community initiative seeking to make research on earthquake forecasting more open and rigorous, pursuing these ends by comparing different forecasts in a competitive setting and basing judgements of accuracy and usefulness on objective grounds. Read more

Measuring Unfair Inequality: Reconciling Equality of Opportunity and Freedom from Poverty

Over the past few decades, rising income inequality has spurred debates around the world. While many call for policies to help redistribute wealth and counter inequality, others argue that inequality is actually necessary to both motivate and reward hard work and economic productivity. But, as LML Fellow Ravi Kanbur and colleagues argue in a recent paper, standard measures of inequality don’t offer a useful basis for this debate over fairness. Read more

Inference on the History of a Randomly Growing Tree

The skeletal outlines of many natural processes resemble growing tree-like networks. Examples include the movement of a disease through a human community, news or rumours through social media or a computer virus through a web of connected computers. The elements in these networks correspond to nodes in the tree, and links or edges between nodes reflect some kind of connection between individuals – Read more

London traffic, climate lawsuits and the paradoxical nature of science

Here are some links to several recent articles by LML External Fellow Mark Buchanan

London’s traffic problems won’t be solved by a new driving tax

Bloomberg Opinion 22 February, 2022

How do you get to work in the morning? If you live within one kilometer, or about half a mile, of a bus or train stop, there’s a good chance you take public transit. If you live further away, you’re much more likely to drive. Read more

Epidemic oscillations induced by social network control: the discontinuous case

Since the early days of control theory,  engineers have understood that feedback can give rise to spontaneous and sustained oscillations. Examples abound in engineering systems such as thermostats and steering devices, as well as in natural and biological systems – for example, in homeostasis or diabetes in the human metabolism. Feedback-induced oscillations have also affected recent governmental efforts to control the covid-19 pandemic crisis through measures such as social distancing, lock downs and quarantine. Read more

The Long Run Evolution of Absolute Intergenerational Mobility

In the mid-20th century, many developed economies experienced several generations of high prosperity, with children generally earning higher incomes than their parents had at the same age. In economics, this is technically known as increasing absolute intergenerational mobility. For the United States, however, studies suggest that such mobility has more recently been falling. It decreased from 90% for children born in 1940 to just 50% for those born in 1980, mostly due to changes in the income distribution, but also due to slower economic growth. Whether this pattern also holds for other countries and birth cohorts is less clear. Read more

Choice history effects in mice and humans improve reward harvesting efficiency

In foraging for food and other resources, animals have to make repeated choices about where best to search. Experimental studies of such decisions typically work with the simplifying assumption that animals’ past decisions should have no impact on the distribution of actual resources, which remains fixed. Many such studies have nevertheless found that animals’ current decisions do often depend on their past decisions, and interpret this as a bias Read more

Aging power spectrum of membrane protein transport and other subordinated random walks

Many biological, physical and social systems exhibit correlations in their dynamics across multiple time scales. Such correlations manifest themselves as a broad spectrum of relaxation times and a 1/f decay in the power spectrum, which reflects temporal self-similarity in the dynamics. Such spectra are observed Read more

Exact simulation of extrinsic stress-release processes

In statistics and probability theory, a point process is a collection of mathematical points randomly located within a mathematical space such as the real line. In earthquake science, such processes are often used to model the occurrence of earthquake events in time, as stress builds in the Earth’s crust before being released at specific moments.
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