The Politics of Public Health: A Response to Epstein

Conservatives are taking aim at the field of public health, targeting its efforts to understand and control environmental and social causes of disease. Richard Epstein and others contend that these efforts in fact undermine people’s health and well-being by eroding people’s incentives to create economic value. Public health, they argue, should stick to its traditional task—the struggle against infectious diseases. Because markets are not up to the task of controlling the transmission of infectious disease, Epstein says, coercive government action is required. But market incentives, not state action, he asserts, represent our best hope for controlling the chronic illnesses that are the main causes of death in industrialized nations. In this article, we assess Epstein’s case. We consider his claims about the market’s capabilities and limits, the roles of personal choice and social influences in spreading disease, and the relationship between health and economic inequality. We argue that Epstein’s critique of public health overreaches, oversimplifies, and veils his political and moral preferences behind seemingly objective claims about the economics of disease control and the determinants of disease spread. Public health policy requires political and moral choices, but these choices should be transparent

Pseudodeterminants and perfect square spanning tree counts

The pseudodeterminant $\textrm{pdet}(M)$ of a square matrix is the last nonzero coefficient in its characteristic polynomial; for a nonsingular matrix, this is just the determinant. If $\partial$ is a symmetric or skew-symmetric matrix then $\textrm{pdet}(\partial\partial^t)=\textrm{pdet}(\partial)^2$. Whenever $\partial$ is the $k^{th}$ boundary map of a self-dual CW-complex $X$, this linear-algebraic identity implies that the torsion-weighted generating function for cellular $k$-trees in $X$ is a perfect square. In the case that $X$ is an \emph{antipodally} self-dual CW-sphere of odd dimension, the pseudodeterminant of its $k$th cellular boundary map can be interpreted directly as a torsion-weighted generating function both for $k$-trees and for $(k-1)$-trees, complementing the analogous result for even-dimensional spheres given by the second author. The argument relies on the topological fact that any self-dual even-dimensional CW-ball can be oriented so that its middle boundary map is skew-symmetric.Comment: Final version; minor revisions. To appear in Journal of Combinatoric

Floppy modes and non-affine deformations in random fiber networks

We study the elasticity of random fiber networks. Starting from a microscopic picture of the non-affine deformation fields we calculate the macroscopic elastic moduli both in a scaling theory and a self-consistent effective medium theory. By relating non-affinity to the low-energy excitations of the network (``floppy-modes'') we achieve a detailed characterization of the non-affine deformations present in fibrous networks.Comment: 4 pages, 2 figures, new figure