Using Multi-Source Data to Assess the Dynamics of Socioeconomic Development in Africa

Frequent and rapid spatially explicit assessment of socioeconomic development is critical for achieving the Sustainable Development Goals (SDGs) at both national and global levels. In the past decades, scientists have proposed many methods for monitoring human activities on the Earth’s surface on various spatiotemporal scales using Defense Meteorological Satellite Program Operational Line System (DMSP-OLS) nighttime lights (NTL) data. However, the DMSP-OLS NTL data and the associated processing methods have limited their reliability and applicability for systematic measuring and mapping of socioeconomic development. This research utilizes Visible Infrared Imaging Radiometer Suite (VIIRS) NTL and the Isolation Forest (iForest) machine learning algorithm for more intelligent data processing to capture human activities. I use machine learning and NTL data to map gross domestic product (GDP) at 1 km2. I then use these data products to derive inequality indexes like GINI coefficients and 20:20 ratios at nationally aggregate levels. I have also conducted a case study based on agricultural production information to estimate subnational GDP in Uganda. This flexible approach processes the data in an unsupervised manner on various spatial scales. Assessments show that this method produces accurate sub-national GDP data for mapping and monitoring human development uniformly in Uganda and across the globe

Nighttime Lights as a Proxy for Economic Performance of Regions

Studying and managing regional economic development in the current globalization era demands prompt, reliable, and comparable estimates for a region’s economic performance. Night-time lights (NTL) emitted from residential areas, entertainment places, industrial facilities, etc., and captured by satellites have become an increasingly recognized proxy for on-ground human activities. Compared to traditional indicators supplied by statistical offices, NTLs may have several advantages. First, NTL data are available all over the world, providing researchers and official bodies with the opportunity to obtain estimates even for regions with extremely poor reporting practices. Second, in contrast to non-standardized traditional reporting procedures, the unified NTL data remove the problem of inter-regional comparability. Finally, NTL data are currently globally available on a daily basis, which makes it possible to obtain these estimates promptly. In this book, we provide the reader with the contributions demonstrating the potential and efficiency of using NTL data as a proxy for the performance of regions

Evidence from Satellite Nighttime Lights

학위논문(박사) -- 서울대학교대학원 : 사회과학대학 경제학부, 2021.8. 곽노준.This dissertation investigates the status and the determinants of regional economic performance in North Korea, overcoming data limitations of regional research on the North Korean economy using nighttime light data and geospatial data. The first chapter estimates regional level GDP per capita, assessing the regional economic inequality of North Korea at the county level using nighttime light as a proxy for economic level. The research calculates base gross regional domestic product (GRDP) per capita based on urbanization rates and Bank of Korea’s GDP estimates and derives nighttime light-based GRDP per capita based on the relationship between base GRDP per capita and nighttime light. It also assesses the inequality of North Korean regions at the county level, revealing severe county-level inequality within the province, representing 87% of the total inequality, whereas most previous studies have focused on between-province inequality. In the second chapter, the determinants of regional economic performance in the Kim Jong-un era are analyzed using nighttime light as a proxy for economic performance, revealing that market size and involvement in trade, measured as proximity to trade hubs, contribute to higher nighttime light, while industries do not appear to have a significant effect. Sanctions are shown to significantly reduce nighttime light overall, but the magnitude of the impact is highly divergent across regions. The damage of sanctions is greater in regions with large markets or near trade hubs. In contrast, regions near major wholesale markets appear to better cope with sanctions, although the aggregate effect of sanctions on the region is negative. In the final chapter, the channel of trade effect on regional economies is investigated for the period of recovery from the “Arduous March,” 2001–2016. Three hypotheses of export-led growth, import-led growth, and marketization channel are examined. Historical data from the Japanese colonial era are used as instrumental variables to manage the endogeneity problem of the market. The results indicate that resource export and growth of market in response to trade are the main channels through which sanctions affect regional economies. Conversely, input import does not affect regional economies through any industry. The findings imply that North Korea’s economic recovery from the Arduous March was mainly the result of resource export and market expansion.본 논문은 북한의 시군 단위 지역경제의 현황 및 결정요인을 분석한다. 자료의 부재로 북한의 지역경제 연구는 매우 미흡한 실정이었으나, 기존에 사용되지 않았던 위성 야간조도 및 지리정보라는 새로운 자료를 활용하여 시장, 무역, 산업, 대북경제 제재가 지역경제에 미치는 영향을 실증적으로 분석한다. 첫 번째 연구에서는 김정은 정권 하 북한의 시군 단위 1인당 GRDP를 추정하고 불평등 수준을 평가한다. 북한의 GDP를 도시인구 비중에 비례하여 각 지역별로 배분한 후, 이와 야간조도 간의 관계를 도출하여 1인당 GRDP 를 추정한다. 또한 이를 바탕으로 지니계수 및 일반화된 엔트로피 지수를 도출해 북한의 불평등 추세를 분석하고 불평등 분해를 실시한다. 분석 결과 북한의 1인당 GRDP에는 지역간 상당한 격차가 있었으며, 도 단위에서는 평양대비 56-71%의 수준을 보였다. 그러나 불평등 분해 결과 도 단위의 격차보다 동일 도 내 시·군 간 격차에 따른 불평등이 약 87%를 차지하여 시·군 단위의 지역경제 연구가 매우 중요한 것으로 나타냈다. 두 번째 연구에서는 시장, 무역, 산업을 중심으로 김정은 정권 하 북한 지역 경제 수준의 결정요인과 대북제재가 지역경제에 영향을 분석한다. 이를 위하여 2013-2019년 야간조도 수준을 지역별 경제 수준의 대리변수로 사용하며, 일 부 지역에서 야간조도 값이 관측되지 않는 좌측중도절단(Left censoring) 문제가 발생함에 따라 OLS와 함께 토빗 모형을 사용한다. 분석 결과 시장 규모와 무역 중심지 접근성이 북한 지역경제수준에 긍정적 영향을 미치는 것으로 나타났으며, 산업변수의 영향력은 유의하게 나타나지 않았다. 한편, 대북제재는 북한의 지역 야간조도를 평균적으로 5.4% 감소시키며 특히 시장 활동이 활발하고 무역접근성이 높은 지역에 더 큰 피해를 입히는 것으로 나타났다. 한편, 제재 하에서 도매시장으로의 접근성이 높은 지역은 상대적으로 제재의 효과가 상쇄되는 것으로 나타났는데, 이는 제재 하에서 북한의 국내유통망이 상대적으로 중요해지고 한정된 자원이 도매시장으로 먼저 집중되기 때문인 것으로 해석된다. 세 번째 연구에서는 두 가지 종류의 야간조도 자료를 결합하여 2001-2016년 무역이 지역경제에 영향을 미치는 경로를 분석한다. 북한의 무역 자료는 연간 시계열만 존재하며 북한의 지역단위 변수들은 시간에 대해 불변하므로 무역변수와 지역변수 간의 교차항을 통하여 무역이 어떠한 경제적 특성을 가진 지역에서 더 큰 영향을 미치는지 분석함으로써 수출주도 성장, 수입주도 성장 및 시장화 촉진의 세 가지 가설을 검증한다. 이 때, 시장 변수에 내생성이 존재할 수 있으므로 일제강점기의 지역별 시장 및 기차역 개수를 시장의 도구변수로 사용하여 이를 해결한다. 분석 결과 수입주도 성장은 유효하지 않았으며, 수출의 경우 광업이 발달한 지역에 더 큰 긍정적 영향을 미치는 것으로 나타났다. 또한 수출과 수입 모두 시장의 규모가 큰 지역에 더 큰 긍정적 영향을 미치는 것으로 나타나 무역이 시장의 성장을 촉진하고, 시장이 지역경제를 성장시키는 긍정적 외부효과가 중요한 역할을 한 것으로 나타났다. 수출의 시장을 통한 영향은 시장 정책과 무관하였으나 수입의 경우 친시장 정책이 심화될수록 긍정적 외부효과가 강화되었다. 이상의 결과는 종합적으로 2000년대 이후 및 김정은 정권 하에서 북한 지역경제 성장의 주요 동력은 시장과 무역 및 그 둘 간의 상호작용임을 보여준다. 김정은 정권하는 물론 고난의 행군 이후 북한 경제의 회복기에도 지역별 시장 발전 수준 및 무역 참여도가 지역 경제수준에 큰 영향을 미쳤다. 또한 2017년 이후의 UN 안보리 대북제재가 북한경제에 부정적 영향을 미쳤으며, 특히 북한의 핵심 성장동력인 시장과 무역에 큰 피해를 입히므로 상당한 실효성을 가짐을 시사한다.Introduction 1 Chapter 1. Estimation of North Korean Regional GDP in 2012-2019 Using Nighttime Light Data 5 1. Introduction 5 2. Nighttime Light Data 8 2.1. Introduction 8 2.2. Features of Energy Use in North Korea 10 2.3. Nighttime Light and Welfare Level 13 3. Method and Data 18 3.1. Methodology 18 3.2. Data 21 4. Results 22 4.1. Estimation of GRDP per capita 22 4.2. Regional Disparity of North Korea 29 5. Conclusions 32 Chapter 2. Determinants of the North Korean Regional Economy and the Effect of Sanctions in the Kim Jong-un Era 34 1. Introduction 34 2. Data and Method 37 2.1. Data 37 2.2. Descriptive Statistics 43 2.3. Methodology 47 3. Results 49 3.1. The Determinants of Regional Economic Growth 49 3.2. The Effect of Sanctions 52 3.3. Transmission Channels of the Sanction Effects 54 3.4. Robustness Check 61 4. Conclusions 70 Chapter 3. The effect of trade on the North Korea Economy: Analysis of the Channel 72 1. Introduction 72 2. Method and Data 75 2.1. Hypothesis 75 2.2. Regression model 77 2.3. Data 79 3. Results 86 3.1. Export-Led Growth 86 3.2. Import-Led Growth 89 3.3. Marketization Channel 91 4. Conclusion 99 Concluding Remarks 100 Appendix 102 Reference 107 국문초록 114박

Aladdin\u27s Magic Lamp: Developing Methods for Calibration and Geolocation Accuracy Assessment of the DMSP OLS

Nighttime satellite imagery from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) has a unique capability to observe nocturnal light emissions from sources including cities, wild fires, and gas flares. Data from the DMSP OLS is used in a wide range of studies including mapping urban areas, estimating informal economies, and estimating urban populations. Given the extensive and increasing list of applications a repeatable method for assessing geolocation accuracy, performing inter-calibration, and defining the minimum detectable brightness would be beneficial. An array of portable lights was designed and taken to multiple field sites known to have no other light sources. The lights were operated during nighttime overpasses by the DMSP OLS and observed in the imagery. A first estimate of the minimum detectable brightness is presented based on the field experiments conducted. An assessment of the geolocation accuracy was performed by measuring the distance between the GPS measured location of the lights and the observed location in the imagery. A systematic shift was observed and the mean distance was measured at 2.9km. A method for in situ radiance calibration of the DMSP OLS using a ground based light source as an active target is presented. The wattage of light used by the active target strongly correlates with the signal measured by the DMSP OLS. This approach can be used to enhance our ability to make inter-temporal and inter-satellite comparisons of DMSP OLS imagery. Exploring the possibility of establishing a permanent active target for the calibration of nocturnal imaging systems is recommended. The methods used to assess the minimum detectable brightness, assess the geolocation accuracy, and build inter-calibration models lay the ground work for assessing the energy expended on light emitted into the sky at night. An estimate of the total energy consumed to light the night sky globally is presented

A new evaluation of the role of urbanization to warming at various spatial scales: Evidence from the Guangdong‐Hong Kong‐Macao Region, China

The urbanization impacts on Surface Air Temperature (SAT) change in the Guangdong‐Hong Kong‐Macao region (GHMR) from 1979 to 2018 are examined using homogeneous surface observations, reanalysis, and remote sensing. Results show that the warming due to urbanization tends to be smaller or insignificant as the spatial scale increases. The urbanization contribution to the local warming can reach as high as 50% in the center of each metropolis, remains high (~25%) in the Greater Bay Area (GBA), and decreases to about 10% in the whole GHMR. The warming in GHMR is nearly uniform throughout the day, and therefore the observed trend of the Diurnal Temperature Range (DTR) is not statistically significant. However, the urbanization contribution exhibits distinct seasonal variations, large in summer and autumn while smaller in winter and spring

Observing the Effects of Diversity on Performance in Ugandan Primary Schools

The goal of all firms is to improve efficiency and performance, and previous literature suggests that diversity among teammates is a mechanism to improve productivity. This research uniquely extends previous understandings of horizontal and vertical diversity by examining school performance metrics as an important indicator of economic outcomes. Using data from the Centre for the Study of African Economies(CSAE) at the University of Oxford, I analyze vertical and horizontal diversity and its effects on teacher groups within Ugandan primary schools. Overall, my results suggest a minimally significant, but positive effect of gender and ethnic diversity on student performance outcomes. My findings contradict existing research, which may be in part due to the difference in work environments that my study utilizes for analysis

Papers on institutional quality and economic development in African regions

This thesis examines the relationship between institutional quality and regional economic development in African countries. It analyses three elements of institutional quality: the impact of institutional quality on economic development, the drivers of poor institutional quality, and interventions that can be adopted to improve institutional quality. The first paper of this PhD, published in the Journal of Development Studies and co-authored with Neil Lee and Andrés Rodríguez-Pose, examines the relationship between sub-national government quality and economic development across 356 regions in 22 African countries. We create a novel index of sub-national government quality using Afrobarometer survey data, and we use high resolution night-time satellite images as a proxy for economic activity. We find that a reduction in sub-national government quality causes decreases in regional economic activity. In the second paper, I examine one of the drivers of sub-national government quality in African regions – armed conflict. I find that armed conflict leads to a deterioration in sub-national government quality. Contrary to the existing literature which suggests that armed conflict leads to a loss of government legitimacy, I find that this occurs because sub-national governments divert resources away from delivering services and towards crisis response. As a result, I find that armed conflict does not lead to a reduction in national government quality as national governments possess much greater resources. Therefore, national governments are able to respond to crises without significantly reducing the quality of service delivery. The third paper, co-authored with Neil Lee, examines the impact of national government quality on spatial inequality within African provinces. We create, for the first time, an index of within-province inequality using high resolution satellite imagery. We find that national government quality is just as important as differences in geographical endowments in driving spatial inequality within provinces. This is primarily because national governments in African countries have a history of city-specific favouritism – i.e. creating policies that benefit a particular city (typically due to corruption, nepotism or clientelism). This city-specific favouritism does not spill-over and benefit the wider province. Instead, it creates and exacerbates inequality within provinces

Industrial Growth in Sub-Saharan Africa: Evidence from Machine Learning with Insights from Nightlight Satellite Images

This study uses nightlight time data and machine learning techniques to predict industrial development in Africa. The results provide the first evidence on how machine learning techniques and nightlight data can be used to predict economic development in places where subnational data are missing or not precise. Taken together, the research confirms four groups of important determinants of industrial growth: natural resources, agriculture growth, institutions, and manufacturing imports. Our findings indicate that Africa should follow a more multisector approach for development, putting natural resources and agriculture productivity growth at the forefront

Detecting spatial pattern of inequality from remote sensing

Spatial inequalities across the globe are not easy to detect and satellite data have shown to be of use in this task. Earth Observation (EO) data combined with other information sources can provide complementary information to those derived from traditional methods. This research shows patterns of inequalities emerging by combining global night lights measured from Earth Observation, population density and built-up in 2015. The focus of the paper is to describe the spatial patterns that emerge by combing the three variables. This work focuses on processing EO data to derive information products, and in combining built-up- and population density with nighttime emission. The built-up surface was derived entirely from remote sensing archives using artificial intelligence and pattern recognition techniques. The built-up was combined with population census data to derive population density. Also the nighttime emission data were available from EO satellite sensors. The three layers are subsequently combined as three colour compositions based on the three primary colours (i.e. red green and blue) to display the “human settlement spatial pattern” maps. These GHSL nightlights provide insights in inequalities across the globe. Many patterns seem to be associated with countries income. Typically, high income countries are very well lit at night, low income countries are poorly lit at night. All larger cities of the world are lit at night, those in low-income countries are often less well lit than cites in high-income countries. There are also important differences in nightlights emission in conflict areas, or along borders of countries. This report provides a selected number of patterns that are described at the regional, national and local scale. However, in depth analysis would be required to assess more precisely that relation between wealth access to energy and countries GDP, for example. This work also addresses regional inequality in GHSL nightlights in Slovakia. The country was selected to address the deprivation of the Roma minority community. The work aims to relate the information from the GHSL nightlights with that collected from field survey and census information conducted at the national level. Socio-economic data available at subnational level was correlated with nightlight. The analysis shows that despite the potential of GHSL nightlights in identifying deprived areas, the measurement scale of satellite derived nightlights at 375 x 375 m and 750 x 750 m pixel size is too coarse to capture the inequalities of deprived communities that occur at finer scale. In addition, in the European context the gradient of inequality is not strong enough to produce strong evidence. Although there is a specific pattern of GHSL nightlights in settlements with high Roma presence, this cannot be used to identify such areas among the others. This work is part of the exploratory data analysis conducted within the GHSL team. The exploratory analysis will be followed by more quantitative assessments that will be available in future work.JRC.E.1-Disaster Risk Managemen