Frameworks for evaluating macroeconomic policies

This thesis brings together the three chapters that together form my PhD thesis. As indicated by the title, Frameworks for Evaluating Macroeconomic Policies, the common theme linking the three is a focus on the development of modeling frameworks that can be used for the evaluation of Macroeconomic policies. Ways in which these models can be compared with each other and with the data are recurrent themes. The first chapter How to Model Money? Racing Monetary Frameworks against the Quantity Theory of Money is about finding frameworks for evaluating monetary policies. Currently three main approaches exist: CashinAdvance, New Keynesian, and SearchMoney. Using empirical facts on the Quantity Theory of Money as a yardstick we compare these three frameworks. It results that all three frameworks are display the Quantity Theory of Money over the longrun, as in the data. But all three frameworks display way too much of the Quantity Theory of Money over the shortrun. The race thus ends in a draw, but one illustrative of the strengths and weaknesses of all three frameworks. The results suggest that better modeling of other causes of inflation, and of heterogeneity, are important to improving monetary models. The second chapter Evaluating a FlatTax Reform is a quantitative modelling of a flattax reform for the US. The modeling focuses on replicating the details of current US taxation and inequality. This later is important as the effects on inequality of such a tax reform are one of the main arguments given against it. The third chapter Estimation of BewleyHuggettAiyagari Models: Theory and Implementation present inprogress work developing theory relevant to simulated moment and simulated likelihood estimation of a class of heterogeneous agent models. Theory focuses on developing the required assumptions directly from model fundamentals, and from accounting for the dependence of the estimation on numerical solution and simulation of the models. Attention is also given to implementation of the estimators, in particular which algorithms work computationally. The three chapters are presented here in the form of three separate articles. However the common thread of developing frameworks for the evaluation of macroeconomic policies is clearly evident throughout. I hope they may be of interest to the readerHow to model money? : racing monetary frameworks against the quantity theory of money. Evaluating a flat-tax reform. Estimation of Bewley-Huggett-Aiyagari models : theory and implementationPresidente: Manuel Santos; Vocal: David Domeij; Secretario: Matthias Kredle

Chronic disease outcomes after severe acute malnutrition in Malawian children (ChroSAM): a cohort study

Background Tackling severe acute malnutrition (SAM) is a global health priority. Heightened risk of non-communicable diseases (NCD) in children exposed to SAM at around 2 years of age is plausible in view of previously described consequences of other early nutritional insults. By applying developmental origins of health and disease (DOHaD) theory to this group, we aimed to explore the long-term eff ects of SAM. Methods We followed up 352 Malawian children (median age 9·3 years) who were still alive following SAM inpatient treatment between July 12, 2006, and March 7, 2007, (median age 24 months) and compared them with 217 sibling controls and 184 age-and-sex matched community controls. Our outcomes of interest were anthropometry, body composition, lung function, physical capacity (hand grip, step test, and physical activity), and blood markers of NCD risk. For comparisons of all outcomes, we used multivariable linear regression, adjusted for age, sex, HIV status, and socioeconomic status. We also adjusted for puberty in the body composition regression model. Findings Compared with controls, children who had survived SAM had lower height-for-age Z scores (adjusted diff erence vs community controls 0·4, 95% CI 0·6 to 0·2, p=0·001; adjusted diff erence vs sibling controls 0·2, 0·0 to 0·4, p=0·04), although they showed evidence of catch-up growth. These children also had shorter leg length (adjusted diff erence vs community controls 2·0 cm, 1·0 to 3·0, p<0·0001; adjusted diff erence vs sibling controls 1·4 cm, 0·5 to 2·3, p=0·002), smaller mid-upper arm circumference (adjusted diff erence vs community controls 5·6 mm, 1·9 to 9·4, p=0·001; adjusted diff erence vs sibling controls 5·7 mm, 2·3 to 9·1, p=0·02), calf circumference (adjusted diff erence vs community controls 0·49 cm, 0·1 to 0·9, p=0·01; adjusted diff erence vs sibling controls 0·62 cm, 0·2 to 1·0, p=0·001), and hip circumference (adjusted diff erence vs community controls 1·56 cm, 0·5 to 2·7, p=0·01; adjusted diff erence vs sibling controls 1·83 cm, 0·8 to 2·8, p<0·0001), and less lean mass (adjusted diff erence vs community controls –24·5, –43 to –5·5, p=0·01; adjusted diff erence vs sibling controls –11·5, –29 to –6, p=0·19) than did either sibling or community controls. Survivors of SAM had functional defi cits consisting of weaker hand grip (adjusted diff erence vs community controls –1·7 kg, 95% CI –2·4 to –0·9, p<0·0001; adjusted diff erence vs sibling controls 1·01 kg, 0·3 to 1·7, p=0·005,)) and fewer minutes completed of an exercise test (sibling odds ratio [OR] 1·59, 95% CI 1·0 to 2·5, p=0·04; community OR 1·59, 95% CI 1·0 to 2·5, p=0·05). We did not detect signifi cant diff erences between cases and controls in terms of lung function, lipid profi le, glucose tolerance, glycated haemoglobin A1c, salivary cortisol, sitting height, and head circumference. Interpretation Our results suggest that SAM has long-term adverse eff ects. Survivors show patterns of so-called thrifty growth, which is associated with future cardiovascular and metabolic disease. The evidence of catch-up growth and largely preserved cardiometabolic and pulmonary functions suggest the potential for near-full rehabilitation. Future follow-up should try to establish the eff ects of puberty and later dietary or social transitions on these parameters, as well as explore how best to optimise recovery and quality of life for survivors

Evaluation of modelled spatially distributed predictions of soil erosion by water versus field-based assessments

Policy makers concerned about soil erosion and its impacts need good quality information on which to base their decisions. There is a trend toward using erosion models to aid such decision making. Such models are based on data obtained from experimental plots. The theoretical results need to be compared with information gained from monitoring erosion in the field to assess if theory accords with reality. Data from the Minimum Information Requirement version of the Water Erosion Prediction Project model (MIRSED) are compared to information gained from field monitoring over a 5-year period (1982–1986) in 11 localities widely spread throughout England and Wales. Two of the localities, Gwent and Shropshire, are examined in detail. The model seriously over predicts erosion, both in amount and extent. Also, the statistical distributions of the data values are different. The model predicts erosion will happen where it does not. The reasons why the two assessments of erosion differ greatly are explored. This comparison shows there is an urgent need to develop models which incorporate information gained from field-based observations. Until better models are devised, policy makers and decision takers should treat the results of modelling exercises with great caution

A New NO-Releasing Nanoformulation for the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a chronicand progressive disease which continues to carry an unacceptablyhigh mortality and morbidity. The nitric oxide (NO) pathwayhas been implicated in the pathophysiology and progressionof the disease. Its extremely short half-life and systemiceffects have hampered the clinical use of NO in PAH. In anattempt to circumvent these major limitations, we have developeda new NO-nanomedicine formulation. The formulationwas based on hydrogel-like polymeric composite NO-releasingnanoparticles (NO-RP). The kinetics of NO release fromthe NO-RP showed a peak at about 120 min followed by asustained release for over 8 h. The NO-RP did not affect theviability or inflammation responses of endothelial cells. TheNO-RP produced concentration-dependent relaxations of pulmonaryarteries in mice with PAH induced by hypoxia. Inconclusion, NO-RP drugs could considerably enhance thetherapeutic potential of NO therapy for PAH

Health on the Move (HOME) Study: Using a smartphone app to explore the health and wellbeing of migrants in the United Kingdom.

Background/Aim: We have a limited understanding of the broader determinants of health of international migrants and how these change over time since migration to the United Kingdom (UK). To address this knowledge gap, we aim to conduct a prospective cohort study with data acquisition via a smartphone application (app). In this pilot study, we aim to 1) determine the feasibility of the use of an app for data collection in international migrants, 2) optimise app engagement by quantifying the impact of specific design features on the completion rates of survey questionnaires and on study retention, 3) gather preliminary profile health status data, to begin to examine how risk factors for health are distributed among migrants. Methods: We will recruit 275 participants through a social media campaign and through third sector organisations that work with or support migrants in the UK. Following consent and registration, data will be collected via surveys. To optimise app engagement and study retention, we will quantify the impact of specific design features (i.e. the frequency of survey requests, the time of day for app notifications, the frequency of notifications, and the wording of notifications) via micro-randomised process evaluations. The primary outcome for this study is survey completion rates with numerator as the number of surveys completed and denominator as the total number of available surveys. Secondary outcomes are study retention rates and ratings of interest after app usage. Ethics and dissemination: We have obtained approval to use consented patient identifiable data from the University College London Ethics Committee. Improving engagement with the app and gathering preliminary health profile data will help us identify accessibility and usability issues and other barriers to app and study engagement prior to moving to a larger study

Prenatal Vitamin D Supplementation and Child Respiratory Health: A Randomised Controlled Trial

PMCID: PMC3691177This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited