Low sonic boom design and performance of a Mach 2.4/1.8 overland high speed civil transport

This paper describes the design features of a Douglas Mach 2.4/1.8 Low Sonic Boom High Speed Civil Transport (HSCT) configuration developed for NASA. The configuration is designed to fly over water at Mach 2.4 for highest productivity and economic worth, and fly over land at Mach 1.8 with reduced sonic boom loudness

Environmental Taxes: Dead or Alive?

Both theory and recent trends suggest some optimism for the future of environment-related taxes. While new research emphasizes the potentially significant distortions created by environmental taxes and appears to undermine the so-called "double dividend" theory, it also suggests that virtually any environmental policy, including regulations, taxes, and tradable permits, can compound existing distortions in the tax system. Currently, direct environmental taxes, such as per-unit charges on emissions, are only in limited use; however, indirect environmental levies, including taxes on fuels, vehicles, beverage containers, and fertilizers, are growing in importance across the OECD nations. Over the period 1990-1993, environmental taxes as a share of total revenue increased while taxes on personal and corporate income declined slightly, indicating a modest tax shift.

Learning First, Technology Second: Enhancing Missionary Training Through Technology

This article describes how the missions agency EFCA ReachGlobal uses the open source online learning platform Moodle to train missionaries and to fulfill its goal to become a learning organization. Moodle is employed in three ways: online facilitated courses, collaboration zones and knowledge banks. Blended learning is also used, notably in ReachGlobal’s pre-field training for missionary candidates

Does the Provision of Free Technical Information Really Influence Firm Behavior?

Significant environmental benefits are often associated with the rapid diffusion of new energy-saving technologies. Over the past decade, the federal government, as well as electric and gas utilities, have begun to provide free technical information to potential buyers to stimulate private investment in certain technologies, particularly for retrofitting existing buildings. Yet it has not been demonstrated that this provision of technical information can truly accelerate the rate of technology diffusion. This study develops a model of firm behavior that incorporates multiple factors in the decision to retrofit high efficiency lighting technologies. Technology retrofit and the acceptance of technical information are modeled as jointly determined dichotomous variables, and their determinants are estimated using a bivariate probit specification. The principal conclusion is that information programs make a significant contribution to the diffusion of high efficiency lighting in commercial office buildings, although these programs are less important than basic price signals.

Curbing Power or Progress? Governing with an Opposition Veto

Veto institutions are often dominated by government opponents with rival electoral and policy interests (e.g. \divided government"). I investigate the tradeoff between policy control and policy blockade when both the government and the veto party may cater to opposing special interests. The value of an opposition veto depends on whether electoral accountability can discipline bad type politicians. When this is not the case, a veto is beneficial only if the government's special interests are expected to be harmful. In contrast, when bad types care about (re-)election, a veto always increases expected welfare, providing a new rationale for the frequent occurrence of "divided government". Without policy rivalry, an opposition veto fares even better.Political Accountability, Opposition, Veto, Divided Government

On the number of 4-cycles in a tournament

If $T$ is an $n$-vertex tournament with a given number of $3$-cycles, what can be said about the number of its $4$-cycles? The most interesting range of this problem is where $T$ is assumed to have $c\cdot n^3$ cyclic triples for some $c>0$ and we seek to minimize the number of $4$-cycles. We conjecture that the (asymptotic) minimizing $T$ is a random blow-up of a constant-sized transitive tournament. Using the method of flag algebras, we derive a lower bound that almost matches the conjectured value. We are able to answer the easier problem of maximizing the number of $4$-cycles. These questions can be equivalently stated in terms of transitive subtournaments. Namely, given the number of transitive triples in $T$, how many transitive quadruples can it have? As far as we know, this is the first study of inducibility in tournaments.Comment: 11 pages, 5 figure