Culture Affects our Beliefs about Firearms, But Data are Also Important

Dan Kahan and Donald Braman’s provocative analysis contends that because people’s beliefs about firearms are primarily formed by cultural values, empirical data are unlikely to have much effect on the gun debate. Their proposed solution to this quandary is that scholars who want to help resolve the gun controversy should identify precisely the cultural visions that generate this dispute and formulate appropriate strategies for enabling those visions to be reconciled in law. In response to Kahan and Braman’s challenge to empirical research, I argue that while culture influences beliefs, it is but one of several such factors. Alongside culture (and presumably other factors as well), empirical evidence has a powerful influence on beliefs about gun control. In the first Part of this Commentary I discuss how cultural beliefs can significantly affect individuals’ beliefs about firearms and discuss strategies for helping people overcome their cultural biases to more honestly evaluate empirical evidence. The second Part provides examples of how data have played an important role in affecting individuals’ beliefs about firearms. I conclude by urging renewed attention to empirical research to inform the gun control debate.

Space, supervenience and substantivalism

[FIRST PARAGRAPH] Consider a straight line on a flat surface running from point A to C and passing though B. Suppose the distance AB to be four inches, and the distance BC to be six inches. We can infer that the distance AC is ten inches. Of all geometrical inferences, this is surely one of the simplest. Of course, things are a little more complicated if the surface is not flat. If A, B and C are points on a sphere, then the shortest distance between A and C may be smaller (it may even be zero). We can make our inference immune from concerns about non-Euclidean spaces, however, by qualifying it as follows: if AB = n, and BC = m, then, in the direction A⇒B⇒C, the distance AC is n + m. This is apparently entirely trivial. But trivial truths can hide significant ontological ones. Let us translate our mathematical example to the physical world, and suppose A, B and C to be points, still in a straight line, but now at the centre of gravity of three physical objects

On some intermediate mean values

We give a necessary and sufficient mean condition for the quotient of two Jensen functionals and define a new class $\Lambda_{f,g}(a, b)$ of mean values where $f, g$ are continuously differentiable convex functions satisfying the relation $f"(t)=t g"(t), t\in \Bbb R^+$. Then we asked for a characterization of $f, g$ such that the inequalities $H(a, b)\le \Lambda_{f, g}(a, b)\le A(a, b)$ or $L(a, b)\le \Lambda_{f, g}(a, b)\le I(a, b)$ hold for each positive $a, b$, where $H, A, L, I$ are the harmonic, arithmetic, logarithmic and identric means, respectively. For a subclass of $\Lambda$ with $g"(t)=t^s, s\in \Bbb R$, this problem is thoroughly solved

Is Inequality really a Major Cause of Violent Crime? Evidence From a Cross-National Panel of Robbery and Violent Theft Rates

This article argues that the link between income inequality and violent property crime might be spurious, complementing a similar argument in prior an alysis by the author on the determinants of homicide. In contrast, Fajnzylber, Lederman & Loayza (1998; 2002a, b) provide seemingly strong and robust evidence that inequality causes a higher rate of both homicide and robbery/violent theft even after controlling for country-specific fixed effects. Ou r results suggest that inequality is not a statistically significant determinant, unless either country- specific effects are not controlled for or the sample is artificially restricted to a small number of countries. The reason why the link between inequality and violent property crime might be spur ious is that income inequality is likely to be strongly correlated with country- specific fixed effects such as cultural differences. A high degree of inequality might be socially undesirable for any number of reasons, but that it causes vi! olent crime is far from proven.

Spectral radius of Hadamard product versus conventional product for non-negative matrices

We prove an inequality for the spectral radius of products of non-negative matrices conjectured by X. Zhan. We show that for all $n\times n$ non-negative matrices $A$ and $B$, $\rho(A\circ B)\le\rho((A\circ A)(B\circ B))^{1/2}\le\rho(AB)$, where $\circ$ represents the Hadamard product.Comment: 4.1 page