Regulating housing vacancies away? The paradoxical effects of mismatch

Policy makers agree that vacant houses are undesirable. Moreover the existence of empty houses is used as an argument for allocating less land for new construction. So higher vacancy rates tend to trigger tighter restrictions on the supply of land. Such tighter restrictions lead to higher prices and, because of the incentives this creates for occupying housing, to lower housing vacancies (‘opportunity cost effect’). There is, however, a second effect ignored by planners: more restrictive planning policies impede the matching process in housing markets so leading to higher vacancies (‘mismatch effect’). Which of these two forces dominates is an empirical question. This is our focus here. Addressing potential reverse causation and other endogeneity concerns, we use a unique panel data set on land use regulation for 350 Local Authorities in England from 1981 to 2011. Our results show that tighter local planning constraints increase local housing vacancy rates, suggesting that the mismatch effect dominates. A one standard deviation increase in local regulatory restrictiveness causes the average local vacancy rate to increase by about 0.9 percentage points (23 percent). The results are economically meaningful and show that pointing to the existence of vacant houses as a reason for being more restrictive in allocating land for housing is counterproductive

You cannot regulate empty houses away

Posted by Christian Hilber (SERC & LSE), Paul Cheshire (SERC & LSE) and Hans Koster (VU Amsterdam) “Almost 57,000 homes in London stand empty…” writes David Smith in the Guardian on May 4th. This he claims is a significant cause of London’s housing problem and the “Key to this is tackling buy-to-leave investing.” The answer to this ‘problem’ is for the mayor to refuse planning permission and for Boroughs ”…to introduce planning restrictions …to prohibit the deliberate practice of letting properties lie empty.“ This is not a view unique to David Smith. For example, the well-known architect Lord Rogers in arguing against the desirability of permitting offices to be converted to housing to help with London’s housing shortage noted: “Why should we rush to convert office blocks when we already have three-quarters of a million homes in England lying empty.

A direct method for analyzing the nonlinear vehicle–structure interaction

This article presents an accurate, efficient and stable algorithm to analyze the nonlinear vertical vehicle-structure interaction. The governing equilibrium equations of the vehicle and structure are complemented with additional constraint equations that relate the displacements of the vehicle with the corresponding displacements of the structure. These equations form a single system, with displacements and contact forces as unknowns, that is solved using an optimized block factorization algorithm. Due to the nonlinear nature of contact, an incremental formulation based on the Newton method is adopted. The vehicles, track and structure are modeled using finite elements to take into account all the significant deformations. The numerical example presented clearly demonstrates the accuracy and computational efficiency of the proposed method

The development of a new accountability measurement framework and tool for global health initiatives

The Global Strategy for Women's Children's and Adolescents' Health emphasizes accountability as essential to ensure that decision-makers have the information required to meet the health needs of their populations and stresses the importance of tracking resources, results, and rights to see 'what works, what needs improvement and what requires increased attention'. However, results from accountability initiatives are mixed and there is a lack of broadly applicable, validated tools for planning, monitoring and evaluating accountability interventions. This article documents an effort to transform accountability markers-including political will, leadership and the monitor-review-act cycle-into a measurement tool that can be used prospectively or retrospectively to plan, monitor and evaluate accountability initiatives. It describes the development process behind the tool including the literature review, framework development and subsequent building of the measurement tool itself. It also examines feedback on the tool from a panel of global experts and the results of a pilot test conducted in Bauchi and Gombe states in Nigeria. The results demonstrate that the tool is an effective aid for accountability initiatives to reflect on their own progress and provides a useful structure for future planning, monitoring and evaluation. The tool can be applied and adapted to other accountability mechanisms working in global health

A Finite Element Computation of the Gravitational Radiation emitted by a Point-like object orbiting a Non-rotating Black Hole

The description of extreme-mass-ratio binary systems in the inspiral phase is a challenging problem in gravitational wave physics with significant relevance for the space interferometer LISA. The main difficulty lies in the evaluation of the effects of the small body's gravitational field on itself. To that end, an accurate computation of the perturbations produced by the small body with respect the background geometry of the large object, a massive black hole, is required. In this paper we present a new computational approach based on Finite Element Methods to solve the master equations describing perturbations of non-rotating black holes due to an orbiting point-like object. The numerical computations are carried out in the time domain by using evolution algorithms for wave-type equations. We show the accuracy of the method by comparing our calculations with previous results in the literature. Finally, we discuss the relevance of this method for achieving accurate descriptions of extreme-mass-ratio binaries.Comment: RevTeX 4. 18 pages, 8 figure

Dynamic behaviour analysis of an english-bond masonry prototype using a homogenized-based discrete FE model

Full Finite Element strategies (the so called micro- and macro- models) are still nowadays the most used ones for the study of large masonry structures. However, macro-modelling still lacks accuracy at a meso-scale in terms of damage localization. On the other hand, micro-models are rather computational demanding and require a cumbersome modelling stage. Thus, homogenization-based frameworks give considerable advantages. Moreover, the study of English bond masonry appears to be disregarded in comparison to the running bond one. On this behalf, a two-step procedure based on homogenization theory is herein presented for the dynamic study of English-bond masonry structures. The presented homogenization approach uses two models at a micro-scale: (i) a plane-stress FE discretization within the concepts of Kirchhoff-Love plate theory; and (ii) a three-dimensional micro-model accounting with the mortar joint discontinuity existent at the thickness direction. Bricks are meshed with elastic elements with linear interpolation and joints are reduced to interfaces which obey to the nonlinear behaviour described by the so-called combined cracking-shearing-crushing model. The procedure allows obtaining homogenized bending moment/torque curvature relationships to be used at a structural level within a FE discrete model implemented in a commercial code. The model relies in rigid quadrilateral elements interconnected by homogenized bending/torque nonlinear springs. The framework is used to study the dynamic behaviour of an English-bond masonry wall benchmark. A macroscopic strategy is also considered to enrich the study. The numerical results are compared with the experimental data and a good agreement has been found.FCT (Portuguese Foundation for Science and Technology), within ISISE, scholarship SFRH/BD/95086/2013. This work was also partly financed by FEDER funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT – Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-00763