Holding periods and investment performance: analysing UK office returns 1983-2003

Drawing on a unique database of office properties constructed for Gerald Eve by IPD, this paper examines the holding periods of individual office properties sold between 1983 and 2003. It quantifies the holding periods of sold properties and examines the relationship between the holding period and investment performance. Across the range of holding periods, excess returns (performance relative to the market) are evenly distributed. There are as many winners as there are losers. The distribution of excess returns over different holding periods is widely spread with the risk of under-performance greater over short holding periods. Over the longer term, excess performance is confined to a narrow range and individual returns are more likely to perform in line with the market as a whole

Confidence assessment in the teaching of basic science

A scheme is described for including information about confidence in the computer‐based assessment of students. After each answer, students declare a confidence level of 1, 2, or 3. If the answer is correct, then this is the mark awarded. If not, marks of 0, ‐2, or ‐6 are awarded Students do well on this scheme if they can discriminate between when they are sure of correct answers and when they are partly guessing. In self‐assessment, students are trained to reflect on their reasoning, and to develop the skills of correct confidence judgement. The task of writing tests is simplified, since it becomes less important to ask complex questions. Simple direct questions discriminate better between students than they do with ordinary marking. Good students answer correctly with high confidence, while weak students moderate their confidence level if they know they are uncertain, or else lose heavily when they make mistakes. Preliminary data are presented from self‐assessment trials amongst medical students

Capturing UK real estate volitility

Volatility, or the variability of the underlying asset, is one of the key fundamental components of property derivative pricing and in the application of real option models in development analysis. There has been relatively little work on volatility in real terms of its application to property derivatives and the real options analysis. Most research on volatility stems from investment performance (Nathakumaran & Newell (1995), Brown & Matysiak 2000, Booth & Matysiak 2001). Historic standard deviation is often used as a proxy for volatility and there has been a reliance on indices, which are subject to valuation smoothing effects. Transaction prices are considered to be more volatile than the traditional standard deviations of appraisal based indices. This could lead, arguably, to inefficiencies and mis-pricing, particularly if it is also accepted that changes evolve randomly over time and where future volatility and not an ex-post measure is the key (Sing 1998). If history does not repeat, or provides an unreliable measure, then estimating model based (implied) volatility is an alternative approach (Patel & Sing 2000). This paper is the first of two that employ alternative approaches to calculating and capturing volatility in UK real estate for the purposes of applying the measure to derivative pricing and real option models. It draws on a uniquely constructed IPD/Gerald Eve transactions database, containing over 21,000 properties over the period 1983-2005. In this first paper the magnitude of historic amplification associated with asset returns by sector and geographic spread is looked at. In the subsequent paper the focus will be upon model based (implied) volatility

Heating and cooling system

A heating and cooling apparatus capable of cyclic heating and cooling of a test specimen undergoing fatigue testing is discussed. Cryogenic fluid is passed through a block clamped to the speciment to cool the block and the specimen. Heating cartridges penetrate the block to heat the block and the specimen to very hot temperaures. Control apparatus is provided to alternatively activate the cooling and heating modes to effect cyclic heating and cooling between very hot and very cold temperatures. The block is constructed of minimal mass to facilitate the rapid temperature changes

High Resolution Mapping in support of UNCLOS Article 76: Seeing the seafloor with new eyes

Since 2003, the Center for Coastal & Ocean Mapping/Joint Hydrographic Center at the University of New Hampshire (UNH) has been conducting multibeam mapping of many U.S. continental margins in areas where there is a potential for an extended continental shelf as defined under Article 76 of the United Nations Convention on the Law of the Sea. UNH was directed by Congress, through funding by the National Oceanic & Atmospheric Administration, to map the bathymetry in areas in the Arctic Ocean, Bering Sea, Gulf of Alaska, Northwest Atlantic, northern Gulf of Mexico, the Northern Mariana Islands, Kingman Reef and Palmyra Atoll (Fig. 1). The purpose of these surveys is to accurately locate the 2500-m isobath and to collect the bathymetry data required to eventually determine the location of the maximum change in gradient on Figure 1. Locations and year of bathymetry mapping (yellow areas) for U.S. UNCLOS concerns. the continental rises. A total area of about 862,000 km2 has been completed; approximately 250,000 km2 remains to be mapped. The area between the ~1000 and ~4800-m isobaths has been mapped on each of the completed margins. The mapping has been conducted with multibeam echosounders (MBES) that typically collect soundings with a spacing of ~50 m or less in the focused water depths. After each area is mapped, the data are gridded at 100-m spatial resolution although higher resolution is possible in the shallower regions. The depth precision achieved on all of the cruises has been \u3c1% of the water depth and typically has been \u3c0.5% of the water depth, based on cross-line comparisons. Navigation on all of the cruises has been acquired with inertial-aided DGPS using commercial differential corrections that provide 2 position accuracies much better than ±5 m. All of the MBES systems used produce acoustic backscatter as well as bathymetry but the backscatter quality varies among systems and conditions. Table 1 is a summary of the mapping completed and of areas yet to be mapped for bathymetry. The data are all processed at sea by UNH personnel during their collection and the data, grids and views of the processed data are posted on the worldwide web soon after completion of each area. The data, grids and images can be viewed and downloaded at http://ccom.unh.edu/law_of_the_sea.html

Timing performance of phased-locked loops in optical pulse position modulation communication systems

An optical digital communication system requires that an accurate clock signal be available at the receiver for proper synchronization with the transmitted signal. Phase synchronization is especially critical in M-ary pulse position modulation (PPM) systems where the optimum decision scheme is an energy detector which compares the energy in each of M time slots to decide which of M possible words was sent. Timing errors cause energy spillover into adjacent time slots (a form of intersymbol interference) so that only a portion of the signal energy may be attributed to the correct time slot. This effect decreases the effective signal, increases the effective noise, and increases the probability of error. A timing subsystem for a satellite-to-satellite optical PPM communication link is simulated. The receiver employs direct photodetection, preprocessing of the detected signal, and a phase-locked loop for timing synchronization. The variance of the relative phase error is examined under varying signal strength conditions as an indication of loop performance, and simulation results are compared to theoretical calculations

AN ECONOMIC EVALUATION OF THE COLORADO RIVER BASIN SALINITY CONTROL PROGRAM

Dissolved salts (salinity) adversely affect numerous urban and agricultural users of Colorado River water in California and Arizona. Congress in 1974 authorized a major salinity control program. Studies of general economic benefits from salinity abatement and the cost per unit of salinity reduction expected from specific proposed projects have been developed by the responsible federal agencies, but no project-by-project evaluation has been published. We find a conceptual basis for a substantial downward revision of prospective economic benefits of salinity abatement. Revised benefits are compared with estimated costs, and only for five of the nineteen projects do economic benefits appear to exceed costs.Resource /Energy Economics and Policy,

Energy Efficency In Housing: An Evaluation Of The Importance Of Increased Wall Thickness

In April 2002 revisions to Part L of the Building Regulations were introduced, to improve the energy efficiency of UK buildings. For many housing schemes using traditional masonry cavity walls this may result in an increased cavity width and a consequent increase in the dwelling footprint. The potential impact that this may have on site utilisation, particularly in the light of planning guidance aimed at increasing site densities, has raised concern within the development community. Developers argue that even minor increases in wall thickness may reduce the number of dwellings on sites, thereby reducing overall profitability. This paper analyses these concerns by investigating the impact of increased wall thickness in the context of two developments constructed in the late 1990s. The existing site layouts were analysed under different footprint assumptions and an assessment made of the capacity of the layout to accommodate footprint increases. The theoretical analysis demonstrates that dwelling numbers are unlikely to be reduced as a result of the standards introduced in 2002. It is only when anticipated future improved standards are applied that dwelling numbers may be affected. However, the paper demonstrates also that dwelling loss is not inevitable and that it is perfectly possible to produce very low energy housing, while still achieving densities in line with planning requirements and with no reduction in the overall quality of a scheme. In the end it is not a matter of wall thickness but of good site layout and good house type design