Three Puzzles on Mathematics, Computation, and Games

In this lecture I will talk about three mathematical puzzles involving mathematics and computation that have preoccupied me over the years. The first puzzle is to understand the amazing success of the simplex algorithm for linear programming. The second puzzle is about errors made when votes are counted during elections. The third puzzle is: are quantum computers possible?Comment: ICM 2018 plenary lecture, Rio de Janeiro, 36 pages, 7 Figure

The cultural, ethnic and linguistic classification of populations and neighbourhoods using personal names

There are growing needs to understand the nature and detailed composition of ethnicgroups in today?s increasingly multicultural societies. Ethnicity classifications areoften hotly contested, but still greater problems arise from the quality and availabilityof classifications, with knock on consequences for our ability meaningfully tosubdivide populations. Name analysis and classification has been proposed as oneefficient method of achieving such subdivisions in the absence of ethnicity data, andmay be especially pertinent to public health and demographic applications. However,previous approaches to name analysis have been designed to identify one or a smallnumber of ethnic minorities, and not complete populations.This working paper presents a new methodology to classify the UK population andneighbourhoods into groups of common origin using surnames and forenames. Itproposes a new ontology of ethnicity that combines some of its multidimensionalfacets; language, religion, geographical region, and culture. It uses data collected atvery fine temporal and spatial scales, and made available, subject to safeguards, at thelevel of the individual. Such individuals are classified into 185 independentlyassigned categories of Cultural Ethnic and Linguistic (CEL) groups, based on theprobable origins of names. We include a justification for the need of classifyingethnicity, a proposed CEL taxonomy, a description of how the CEL classification wasbuilt and applied, a preliminary external validation, and some examples of current andpotential applications

Political economy and life course patterns: the heterogeneity of occupational, family and household trajectories of young spaniards

We explore the strong linkages between macro changes and the dynamics of educational, occupational, family, and residential careers of young Spanish adults born between 1945 and 1974. We review theory and evidence on macro factors: changes in the welfare system, centrality of the family as a service provider, and the changing role of women. We outline some hypotheses of how life course trajectories, and their heterogeneity, change across cohorts. We build data on sequences of states using FFS. In our analysis, we find an increase in the discontinuity of careers and of the heterogeneity among cohort members, especially for employment. Women´s careers are becoming more similar to those of men. Family and household formation is postponed, with a limited spread of post-nuclear family forms.

An ontology of ethnicity based upon personal names: with implications for neighbourhood profiling

Understanding of the nature and detailed composition of ethnic groups remains key to a vast swathe of social science and human natural science. Yet ethnic origin is not easy to define, much less measure, and ascribing ethnic origins is one of the most contested and unstable research concepts of the last decade - not only in the social sciences, but also in human biology and medicine. As a result, much research remains hamstrung by the quality and availability of ethnicity classifications, constraining the meaningful subdivision of populations. This PhD thesis develops an alternative ontology of ethnicity, using personal names to ascribe population ethnicity, at very fine geographical levels, and using a very detailed typology of ethnic groups optimised for the UK population. The outcome is an improved methodology for classifying population registers, as well as small areas, into cultural, ethnic and linguistic groups (CEL). This in turn makes possible the creation of much more detailed, frequently updatable representations of the ethnic kaleidoscope of UK cities, and can be further applied to other countries. The thesis includes a review of the literature on ethnicity measurement and name analysis, and their applications in ethnic inequalities and geographical research. It presents the development of the new name to ethnicity classification methodology using both a heuristic and an automated and integrated approach. It is based on the UK Electoral Register as well as several health registers in London. Furthermore, a validation of the proposed name-based classification using different datasets is offered, as well as examples of applications in profiling neighbourhoods by ethnicity, in particular the measurement of residential segregation in London. The main study area is London, UK

The Development of Political Institutions

While the literature on “new institutionalism” explains the stability of institutional arrangements within countries and the divergence of paths of institutional development between countries, Federico Ferrara takes a “historical institutionalist” approach to theorize dynamic processes of institutional reproduction, institutional decay, and institutional change in explaining the development of political institutions. Ferrara synthesizes “power-based” or “power-distributional” explanations and “ideas-based” “legitimation explanations.” He specifies the psychological “microfoundations” of processes of institutional development, drawing heavily from the findings of experimental psychology to ensure that the explanation is grounded in clear and realistic assumptions regarding human motivation, cognition, and behavior. Aside from being of interest to scholars and graduate students in political science and other social-scientific disciplines whose research concentrates on the genesis of political institutions, their evolution over time, and their impact on the stability of political order and the quality of governance, the book will be required reading in graduate courses and seminars in comparative politics where the study of institutions and their development ranks among the subfield’s most important subjects

Assessing significance in a Markov chain without mixing

We present a new statistical test to detect that a presented state of a reversible Markov chain was not chosen from a stationary distribution. In particular, given a value function for the states of the Markov chain, we would like to demonstrate rigorously that the presented state is an outlier with respect to the values, by establishing a $p$-value for observations we make about the state under the null hypothesis that it was chosen uniformly at random. A simple heuristic used in practice is to sample ranks of states from long random trajectories on the Markov chain, and compare these to the rank of the presented state; if the presented state is a $0.1\%$-outlier compared to the sampled ranks (i.e., its rank is in the bottom $0.1\%$ of sampled ranks) then this should correspond to a $p$-value of $0.001$. This test is not rigorous, however, without good bounds on the mixing time of the Markov chain, as one must argue that the observed states on the trajectory approximate the stationary distribution. Our test is the following: given the presented state in the Markov chain, take a random walk from the presented state for any number of steps. We prove that observing that the presented state is an $\varepsilon$-outlier on the walk is significant at $p=\sqrt {2\varepsilon}$, under the null hypothesis that the state was chosen from a stationary distribution. Our result assumes nothing about the structure of the Markov chain beyond reversibility, and we construct examples to show that significance at $p\approx\sqrt \varepsilon$ is essentially best possible in general. We illustrate the use of our test with a potential application to the rigorous detection of gerrymandering in Congressional districtings.Comment: 15 pages, 3 figure

Development, A question of Opportunity. A critique of the 2006 World Development Report, Equity and Development

The World Bank’s World Development Report 2006 addresses Equity and Development. It defines equity as respect for equal opportunities combined with the avoidance of absolute deprivation. Even though justice theories have long been interested in equity (given that equality of opportunity is one of the recognised values of Western society), it has hitherto remained a marginal issue in development economics. Our critique presents a detailed analysis of this report in the light of recent economic studies on this subject and endeavours to place it in the context of the evolution of World Bank thinking and policies. The first part illustrates the wealth of this concept, with its downside being that it is hard to accurately define. The second part demonstrates the gap between the prospects opened up by the enlargement of the development goals beyond poverty reduction and the report’s policy recommendations, which are generally an extension of the World Bank’s traditional analyses. The future of the equity concept for development policy-making could be closely dependent on the development community’s ability to take on board both all its complexity and wealth.

Evaluation of community-level interventions to increase early initiation of antenatal care in pregnancy: protocol for the Community REACH study, a cluster randomised controlled trial with integrated process and economic evaluations

BACKGROUND: The provision of high-quality maternity services is a priority for reducing inequalities in health outcomes for mothers and infants. Best practice includes women having their initial antenatal appointment within the first trimester of pregnancy in order to provide screening and support for healthy lifestyles, well-being and self-care in pregnancy. Previous research has identified inequalities in access to antenatal care, yet there is little evidence on interventions to improve early initiation of antenatal care. The Community REACH trial will assess the effectiveness and cost-effectiveness of engaging communities in the co-production and delivery of an intervention that addresses this issue. METHODS/DESIGN: The study design is a matched cluster randomised controlled trial with integrated process and economic evaluations. The unit of randomisation is electoral ward. The intervention will be delivered in 10 wards; 10 comparator wards will have normal practice. The primary outcome is the proportion of pregnant women attending their antenatal booking appointment by the 12th completed week of pregnancy. This and a number of secondary outcomes will be assessed for cohorts of women (n = approximately 1450 per arm) who give birth 2-7 and 8-13 months after intervention delivery completion in the included wards, using routinely collected maternity data. Eight hospitals commissioned to provide maternity services in six NHS trusts in north and east London and Essex have been recruited to the study. These trusts will provide anonymised routine data for randomisation and outcomes analysis. The process evaluation will examine intervention implementation, acceptability, reach and possible causal pathways. The economic evaluation will use a cost-consequences analysis and decision model to evaluate the intervention. Targeted community engagement in the research process was a priority. DISCUSSION: Community REACH aims to increase early initiation of antenatal care using an intervention that is co-produced and delivered by local communities. This pragmatic cluster randomised controlled trial, with integrated process and economic evaluation, aims to rigorously assess the effectiveness of this public health intervention, which is particularly complex due to the required combination of standardisation with local flexibility. It will also answer questions about scalability and generalisability. TRIAL REGISTRATION: ISRCTN registry: registration number 63066975 . Registered on 18 August 2015