The Effect of Broadleaf Canopies on Survey-grade Horizontal GPS/GLONASS Measurements

A study was conducted to empirically determine the degradation of survey-grade GPS horizontal position measurements due to the effects of broadleaf forest canopies. The measurements were taken using GPS/GLONASS-capable receivers measuring C/A and P-codes, and carrier phase. Fourteen survey markers were chosen in central Connecticut to serve as reference markers for the study. These markers had varying degrees of sky obstruction due to overhanging tree canopies. Sky obstruction was measured by photographing the sky with a 35mm reflex camera fitted with a hemispherical lens. The negative was scanned and the image mapped using an equal- area projection to remove the distortion caused by the lens. The resulting digital image was thresholded to produce a black-and-white image in which a count of the black pixels is a measure of sky-area obstruction. The locations of the markers were determined independently before the study. During the study, each marker was occupied for four 20-minute sessions over the period of one week in mid-July, 1999. The location of the study markers produced relatively long baselines, as compared with similar studies. We compared the accuracy of GPS-only vs. GPS&GLONASS as a function of sky obstruction. Based on our results, GLONASS observations did not improve or degrade the accuracy of the position measurements. There is a loss of 2mm of accuracy per percent of sky obstruction for both GPS only and GPS&GLONASS.

Minimizing the Price of Tranquility: How to Discourage Scotland's Secession from the United Kingdom

What some view as overly-generous funding of the Scottish parliament results from Scotland.s credible threat to secede from the United Kingdom. Scotland is shown to benefit from a second mover advantage in a non-cooperative sequential game over the allocation of public funds. Various reform proposals are criticized for not recognizing that reform of Scottish government finances must be consistent with Scotland.s credible threat. Fiscal autonomy -- in which the Scottish parliament finances a much greater proportion of its spending from Scottish-sourced taxes, is demonstrated to be a viable reform within the existing political context and, in some circumstances, could remove Scotland.s second mover advantage. We also use a cooperative bargaining game model to demonstrate that an Australian style grants commission would not be a viable reform in the British context.

Intergenerational Conflict and the Political Economy of School Spending

In this paper we use survey data to examine support among voters from different age cohorts for public school spending. The survey asked potential voters in California how they intended to vote on two initiatives, one a statewide initiative that would increase spending on public schools throughout the state and the other a local initiative that would increase spending only in the respondent's local school district. We find that older voters without children generally oppose increases in state spending but are much more willing to support local spending. We examine two explanations for this voting pattern, namely the capitalization of local spending into housing values and intergenerational altruism. Our results do not strongly favor one explanation over the other. Consequently, we conclude that both factors (capitalization and intergenerational altruism) probably play important roles in sustaining support among older voters for local school spending.

Who's in Charge in the Inner City? The Conflict Between Efficiency and Equity in the Design of a Metropolitan Area

A circular metropolitan area consists of an inner city and a suburb. Households sort over the two jurisdictions based on public service levels and their costs of commuting to the metropolitan center. Using numerical simulations, we show (1) there typically exist two equilibria: one in which the poor form the majority in the inner city and the other in which the rich form the majority in the inner city; (2) there is an efficiency vs. equity trade-off as to which equilibrium is preferred; and (3) if the inner city contains only poor households, equity favors expanding the inner city to include rich households.