Bad Analogies Cause Even Worse Science

Homicide as Infectious Disease: Using Public Health Methods to Investigate the Diffusion of Homicide

April Zeoli et al.
Justice Quarterly, forthcoming

Abstract: This study examined the spatial and temporal movement of homicide in Newark, New Jersey from January 1982 through September 2008. We hypothesized that homicide would diffuse in a similar process to an infectious disease with firearms and gangs operating as the infectious agents. A total of 2,366 homicide incidents were analyzed using SaTScan v.9.0, a cluster detection software. The results revealed spatio-temporal patterns of expansion diffusion: overall, firearm and gang homicide clusters in Newark evolved from a common area in the center of the city and spread southward and westward over the course of two decades. This pattern of movement has implications in regards to the susceptibility of populations to homicide, particularly because northern and eastern Newark remained largely immune to homicide clusters. The theoretical and practical implications of the findings, as well as recommendations for future research, are discussed.

Suppose murder were like a rutabaga.  Then, it would be mostly dirty and underground, with a green leafy top.  And you could stop murder with herbicide.  If murder were like a rutabaga, that is.  It's not.  But then it's also not an infectious disease.  As Röyksopp  put it, "brave men tell the truth; the wise man's tools are analogies and puzzles."

Nod to Kevin Lewis

It's not just me anymore

The latest progressive meme is that the government should run like a business and any business in the government's situation would rationally and profitably borrow a lot of money and invest it right now. Mark Thoma and P. Krugman have made arguments like this and Ezra K. has a recent plaintive one in the WaPo.

The problems with this line of reasoning are many. For example, (1) the government ISN'T a business. Profit (or even ROI) is not its bottom line. (2) If the government were a business, its shareholders (i.e. us) wouldn't have to wait til November to boot our current management team. (3) In most businesses that I am aware of, management cannot vote to help themselves to more money from their shareholders.

People, it's not just me anymore; the "American street" simply doesn't trust the government to do things right.

At least Ezra does recognize that our government doesn't "do" infrastructure in a business-like manner:

The problem is that the way we choose our infrastructure projects is an embarrassment. About 10 percent of infrastructure spending comes from politicians securing earmarks. Most of the rest depends on a formula in which the government just hands money over to the states. There's no requirement for cost-benefit analysis or rate-of-return calculations. The decisions are horribly politicized.

Nice, but then he just hand-waves it away by saying we need to tie further massive borrowing to vague "reforms".

Good luck on that one, EK!