Now showing 1 - 10 of 41
  • Publication
    Direct Standard Errors for Regressions with Spatially Autocorrelated Residuals
    (University College Dublin. School of Economics, 2020-03)
    Regressions using data with known locations are increasingly used in empirical economics, and several standard error corrections are available to deal with the fact that their residuals tend to be spatially correlated. Unfortunately, different corrections commonly return significance levels that vary by several orders of magnitude, leaving the researcher uncertain as to which, if any, is valid. This paper proposes instead an extremely fast and simple procedure to derive standard errors directly from the spatial correlation structure of regression residuals. Importantly, because the estimated covariance matrix gives optimal weights to predict each residual as a linear combination of all residuals, the reliability of these standard errors is self-checking by construction. The approach extends immediately to instrumental variables, and balanced and unbalanced panels, as well as a wide class of nonlinear models. A step by step guide to estimating these standard errors is given in the accompanying tutorials.
  • Publication
    Developing rotten institutions
    (University College Dublin. School of Economics, 2005-08)
    This paper models corruption as optimal parasitism in organizations where teams of agents are weakly restrained by principals. Each agent takes on part of the role of principal, choosing how much to invest in policing to repress corruption in others and how rapaciously to act when unpoliced opportunities arise. This simple model incorporates most of the factors stressed in empirical analyses of corruption, and gives rise to a wide variety of equilibria. Allow income to co-evolve with corruption, we show how adding corruption to a textbook exogenous growth model leads to a Lucas paradox. When income and corruption affect each other suffciently strongly, economies converge to two corner equilibria despite diminishing returns to capital: a rich, clean corner and a poor, corrupt one; a pattern that appears to characterize international data. This paper is part of the International Trade and Investment Programme of the Geary Institute at UCD.
  • Publication
    Living standards and mortality since the Middle Ages
    (University College Dublin. School of Economics, 2010-09) ;
    Existing studies find little connection between living standards and mortality in England, but go back only to the sixteenth century. Using new data on inheritances, we extend estimates of mortality back to the mid-thirteenth century and find, by contrast, that deaths from unfree tenants to the nobility were strongly affected by harvests. Looking at a large sample of parishes after 1540, we find that the positive check had weakened considerably by 1650 even though real wages were falling, but persisted in London for another century despite its higher wages. In both cases the disappearance of the positive check coincided with the introduction of systematic poor relief, suggesting that government action played a role in breaking the link between harvest failure and mass mortality.
  • Publication
    The Irish credit bubble
    (University College Dublin. School of Economics, 2009-12-21)
  • Publication
    Agricultural output, calories and living standards in England before and during the Industrial Revolution
    (University College Dublin. School of Economics, 2012-04) ;
    This paper surveys the results of four recent, separate attempts at estimating agricultural output and food availability in England and Wales at points between the Middle Ages and the Industrial Revolution. It highlights their contrasting implications for trends in economic growth and nutritional status over time. It also offers some suggestions aimed at narrowing gaps between the evidence and how it has been interpreted.
  • Publication
    A Note on the Size Distribution of Irish Mortgages
    (University College Dublin. School of Economics, 2011-08)
    Using Department of Environment data on number of mortgages by size category we find that the Weibull distribution accurately models the distribution of loans under €300,000 but severely underestimates the number of larger loans. We therefore use a a Pareto distribution for loans above this level. We estimate that from 2006 to 2008 there were fewer than 2,000 loans over €1 million with total value of €3 billion; and that there were 11,000 loans over €500,000 with estimated value of €9 billion. While the number of people taking out these mortgages is unknown, the conjecture that the largest 10,000 mortgage borrowers owe around €10 billion, largely for buy to let mortgages, does not appear implausible given these results. More tentatively, an ecological inference procedure suggests that interest only mortgages went almost exclusively to property investors.
  • Publication
    The Preventive Check in Medieval and Pre-industrial England
    (University College Dublin. School of Economics, 2011-05) ;
    England’s post-Reformation demographic regime has been characterized as 'low pressure'. Yet the evidence hitherto for the presence of a preventive check, defined as the short-run response of marriage and births to variations in living standards, is rather weak. New evidence in this paper strengthens the case for the preventive check in both medieval and early modern England. We invoke manorial data to argue the case for a preventive check on marriages in the middle ages. Our analysis of the post-1540 period, based on parish-level rather than aggregate data, finds evidence for a preventive check on marriages and births.
  • Publication
    Understanding Persistence
    (University College Dublin. School of Economics, 2020-09)
    A large literature on persistence finds that many modern outcomes strongly reflect characteristics of the same places in the distant past. These studies typically combine unusually high t statistics with severe spatial autocorrelation in residuals, suggesting that some findings may be artefacts of underestimating standard errors or of fitting spatial trends. For 25 studies in leading journals, I apply three basic robustness checks against spatial trends and find that effect sizes typically fall by over half, leaving most well known results insignificant at conventional levels. Turning to standard errors, there is currently no data-driven method for selecting an appropriate HAC spatial kernel. The paper proposes a simple procedure where a kernel with a highly flexible functional form is estimated by maximum likelihood. After correction, standard errors tend to rise substantially for cross sectional studies but to fall for panels. Overall, credible identification strategies tend to perform no better than naive regressions. Although the focus here is on historical persistence, the methods apply to regressions using spatial data more generally.
  • Publication
    Ready for Revolution? The English Economy before 1800
    (University College Dublin. School of Economics, 2014-11) ;
    Sustained economic growth in England can be traced back to the early seventeenth century. That earlier growth, albeit modest, both generated and was sustained by a demographic regime that entailed relatively high wages, and by an increasing endowment of human capital in the form of a relatively adaptable and skilled labour force. Healthier and savvier English workers were better equipped to profit from the technological possibilities available to them, and to build on them. Technological change and economic growth stemmed from such human capital rather than Boserupian forces. They were the product of England’s resource endowment and its institutions.
  • Publication
    Living standards and plague in London, 1560–1665
    (University College Dublin. School of Economics, 2013-07) ; ;
    We use individual records of 920,000 burials and 630,000 baptisms to reconstruct the spatial and temporal patterns of birth and death in London from 1560 to 1665, a period dominated by recurrent plague. The plagues of 1563, 1603, 1625, and 1665 appear of roughly equal magnitude, with deaths running at five to six times their usual rate, but the impact on wealthier central parishes falls markedly through time. Tracking the weekly spread of plague before 1665 we find a consistent pattern of elevated mortality spreading from the same northern suburbs. Looking at the seasonal pattern of mortality, we find that the characteristic autumn spike associated with plague continued into the early 1700s. Given that individual cases of plague and typhus are frequently indistinguishable, claims that plague suddenly vanished after 1665 should be treated with caution. Natural increase improved as smaller plagues disappeared after 1590, but fewer than half of those born survived childhood.