On the visible size and geometry of aggressively expanding civilizations at cosmological distances

If a subset of advanced civilizations in the universe choose to rapidly expand into unoccupied space, these civilizations would have the opportunity to grow to a cosmological scale over the course of billions of years. If such life also makes observable changes to the galaxies they inhabit, then it is possible that vast domains of life-saturated galaxies could be visible from the Earth. Here, we describe the shape and angular size of these domains as viewed from the Earth, and calculate median visible sizes for a variety of scenarios. We also calculate the total fraction of the sky that should be covered by at least one domain. In each of the 27 scenarios we examine, the median angular size of the nearest domain is within an order of magnitude of a percent of the whole celestial sphere. Observing such a domain would likely require an analysis of galaxies on the order of a Gly from the Earth.Comment: 12 pages, 4 figures, 1 table. References added and updated. New figure added (fig. 4). Additional discussion added. Minor numerical corrections to table 1 (bug fixed

Estimates for the number of visible galaxy-spanning civilizations and the cosmological expansion of life

If advanced civilizations appear in the universe with an ability and desire to expand, the entire universe can become saturated with life on a short timescale, even if such expanders appear rarely. Our presence in an apparently untouched Milky Way thus constrains the appearance rate of galaxy-spanning Kardashev type III (K3) civilizations, if it is assumed that some fraction of K3 civilizations will continue their expansion at intergalactic distances. We use this constraint to estimate the appearance rate of K3 civilizations for 81 cosmological scenarios by specifying the extent to which humanity is a statistical outlier. We find that in nearly all plausible scenarios, the distance to the nearest visible K3 is cosmological. In searches for K3 galaxies where the observable range is limited, we also find that the most likely detections tend to be expanding civilizations who have entered the observable range from farther away. An observation of K3 clusters is thus more likely than isolated K3 galaxies.Comment: 11 pages, 3 figures. In press, International Journal of Astrobiology. v2: Discussion added. Figures re-formated. Typos corrected. References added and update

On the Welfare Consequences of Political Activity

When economic actors are also allowed to become politically active, perhaps to influence a government price policy, they face decision problems with essentially simultaneous political and economic features. If, in addition, two groups struggle to pull the administered price level in opposite directions, an important strategic component is introduced. On two levels, then, such situations depart from the competitive economy framework of Arrow and Debreu. The model of this paper is designed to reconcile the general equilibrium model with politically active interest groups. This model is then used to assess the welfare consequences of such lobbying activity. We find that very often a lobbying program with price distortions is not the best means for regulating these economies. However, there may be cases in which no alternative policy could achieve the outcome resulting from the lobbying program. Keywords: Political economy, lobbying behavior, rent-seeking, distortionary policy.Political economy, lobbying behavior, rent-seeking, distortionary policy., Political Economy,

"Profits: The Views of Jerome Levy and Michal Kalecki"

Profits are the incentive for production and therefore employment in almost all of the world's economies; they also may represent exploitation of workers and consumers. Jerome Levy, using a complex process, derived the profits identity during the years 1908-1914. Michal Kalecki, taking advantage of the development of national accounting, derived it in the 1930s. Levy viewed the equation as a tool for developing policies that would enable capitalist economies to achieve high rates of employment. Recent American experience gives weight to his views. Kalecki's insights from the identity strengthened his belief that unemployment was inescapable under capitalism. He would find empirical support in Europe's high unemployment rates during the past two decades.

Continuous Differentiability of Renormalized Intersection Local Times in R^{1}

We study $\gamma_{k}(x_2,...,x_k;t)$, the k-fold renormalized self-intersection local time for Brownian motion in $R^1$. Our main result says that $\gamma_{k}(x_2,...,x_k;t)$ is continuously differentiable in the spatial variables, with probability 1

Mutual Fund Performance with Learning Across Funds

This paper is based on the premise that knowledge about the alphas of one set of funds will influence an investor's beliefs about other funds. This will be true insofar as an investor's expectation about the performance of a fund is partly a belief about the abilities of mutual fund managers as a group and, more generally, a belief about the degree to which financial markets are efficient. We develop a simple framework for incorporating this prior dependence' and find that it can have a substantial impact on the cross-section of posterior beliefs about fund performance as well as asset allocation. Under independence, the maximum posterior mean alpha increases without bound as the number of funds increases and 'extremely large' estimates are randomly observed. This is true even when fund managers have no skill. In contrast, with prior dependence, investors aggregate information across funds to form a general belief about the potential for abnormal performance. Each fund's alpha estimate is shrunk toward the aggregate estimate, mitigating extreme views. An additional implication is that restricting the estimation to surviving funds, a common practice in this literature, imparts an upward bias to the average fund alpha.