Sonet-1: Social network analysis and modeling system

SONET-I is a preliminary but completely operational version of a package of computer programs for the analysis of social structure. The programs were written to implement a strategy for the analysis of social networks which the authors have developed over the past several years. The conceptual basis for the research method has its origins in graph theory on the one hand and in anthropological studies of social organization — especially kinship studies — on the other. The method can, in fact, be seen as a graph theoretic formalization and generalization of kinship-based methods of social analysis often associated with British social anthropology.     

Internal cohesion of ls sets in graphs

Let G be a finite connected graph. A set of vertices H ? V(G) is called a LS set if for every proper subset K ? H, there are more edges linking K to H ? K than there are linking K to V(G)-H. Since “cliques” in social networks have usually been seen informally as sets of individuals more closely tied to each other than to outsiders, LS sets provide a natural realization of the “clique” concept. In this paper, it is shown that LS sets in social networks have cohesive properties that make them even more useful for empirical analyses. In particular, subgraphs induced by LS subsets remain connected even after several edges have been removed. Results bounding the number of edges that can be so removed are used to get an upper bound for the diameter of subgraphs induced by LS subsets.     

Overcoming the zero interest-rate bound: A quantitative prescription

Using a macro-econometric model we provide a quantitative estimate of the cash transfer or tax cut that would achieve recovery from a severe recession when the central bank is unable to achieve full recovery because of the zero bound. We introduce an automatic transfer and simulate its triggering in the severe recession. We find that an automatic transfer that averages 3% of quarterly GDP repeated four times (quarterly) reduces the unemployment rate an additional full percentage point and thereby completes the recovery. We recommend that legislatures enact an automatic counter-cyclical fiscal policy that will assure adequate stimulus without generating a long-term debt problem.     

A phased increase in the U.S. investment rate: Sacrifice times, T-year gains, and investment rate returns

We simulate a phased increase in the U.S. investment rate using a translog production function with technical progress (disembodied and/or embodied). We assume there will be an absorption lag implying that factors are underutilized during the transition to a higher investment rate. We find that the “sacrifice time” (the time that elapses until consumption surpasses the value it would have had under the initial investment rate) is roughly nine years. Across alternative specifications, phase-in periods, and absorption lags, the sacrifice time varies from seven to 13 years, and is insensitive to the percentage increase in the investment rate. With a three-year phase-in of a 20 percent increase in the investment rate with a one-year absorption lag, the average “ecade gain” in output (the percentage gain at the end of a decade) is roughly 4 percent; the decade gain in consumption, 0 percent; the five-decade gain, 10 percent in output and 6 percent in consumption; and the “investment rate return” (the internal rate of return on a permanent increase in the investment rate), 13 percent.