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Jeffrey D. Michler

Publications and source records attributed to Jeffrey D. Michler.

11 recordsLinked to original sources

The uses (and misuses) of Earth Observation data for weather and vegetation analysis

Integrating gridded Earth observation and weather data into impact evaluations holds great promise. These data allow researchers to capture environmental context, external shocks, and intervention outcomes (e.g., land cover change and agricultural production) that surveys might miss due to spatial or temporal data collection constraints. However, with great power comes great responsibility: The growing ease with which researchers can extract and analyze time series from these datasets can obscure complex geospatial and measurement issues affecting the magnitude, direction, and interpretation of impact estimates. This chapter highlights common challenges associated with the use of weather, vegetation, and extreme event data in the context of geospatial impact evaluation, while providing practical guidance and resources to help researchers judiciously use and avoid misusing these datasets.

physics.soc-ph

Treatment Geometry and Causal Identification with Earth Observation Data

A central task in conducting impact evaluations is determining who or what was exposed to a treatment, when, and to what degree. These questions can be especially complex in geospatial settings, where many reasonable definitions of exposure may exist. This chapter introduces treatment geometry as a core concept in geospatial impact evaluation (GIE): the spatial and temporal footprint of a treatment as represented in data. How this footprint is defined shapes identification strategies and the credibility of causal inference. Drawing on cases spanning the air pollution, wildfire, forest policy, infrastructure, pest, and food security literature, the chapter provides practical guidance on navigating key tradeoffs (including spatial resolution, temporal alignment, spillovers, and boundary uncertainty) that arise when translating real-world interventions into analyzable data. Rather than prescribing a single best approach, the chapter equips researchers with a framework for diagnosing which geometry decisions may matter most in their context, closing with synthesis questions to help readers navigate these decisions.

econ.EM

Impact Evaluations in Data Poor Settings: The Case of Stress-Tolerant Rice Varieties in Bangladesh

New technologies are sometimes introduced at times or in places that lack the necessary data to conduct a well-identified impact evaluation. We develop a methodology that combines Earth observation (EO) data and advances in machine learning with administrative and survey data so as to allow researchers to conduct impact evaluations when traditional economic data is missing. To demonstrate our method, we study stress tolerant rice varieties (STRVs) first introduced to Bangladesh 15 years ago. Using EO data on rice production and flooding for the entire country, spanning two decades, we find evidence of STRV effectiveness. We highlight how the nature of the technology, which is only effective under a specific set of circumstances, creates a Goldilocks Problem that EO data is particularly well suited to addressing. Our findings speak to the promises and challenges of using EO data to conduct impact evaluations in data poor settings.

econ.GN

Food Without Fire: Nutritional and Environmental Impacts from a Solar Stove Field Experiment

Population pressure is speeding the rate of deforestation in Sub-Saharan Africa, increasing the cost of biomass cooking fuel, which over 80 percent of the population relies upon. Higher energy input costs for meal preparation command a larger portion of household spending which in turn induces families to focus their diet on quick cooking staples. We use a field experiment in Zambia to investigate the impact of solar cook stoves on meal preparation choices and expenditures on biomass fuel. Participants kept a detailed food diary recording every ingredient and fuel source used in preparing every dish at every meal for every day during the six weeks of the experiment. This produces a data set of 93,606 ingredients used in the preparation of 30,314 dishes. While treated households used the solar stoves to prepare around 40 percent of their dishes, the solar stove treatment did not significantly increase measures of nutritional diversity nor did treated households increase the number of dishes per meal or reduce the number of meals they skipped. However, treated households significantly reduced the amount of time and money spent on obtaining fuel for cooking. These results suggest that solar stoves, while not changing a household's dietary composition, does relax cooking fuel constraints, allowing households to prepare more meals by reducing the share of household expenditure that goes to meal preparation.

econ.GN

The Mismeasure of Weather: Using Remotely Sensed Earth Observation Data in Economic Context

The availability of weather data from remotely sensed Earth observation (EO) data has reduced the cost of including weather variables in econometric models. Weather variables are common instrumental variables used to predict economic outcomes and serve as an input into modelling crop yields for rainfed agriculture. The use of EO data in econometric applications has only recently been met with a critical assessment of the suitability and quality of this data in economics. We quantify the significance and magnitude of the effect of measurement error in EO data in the context of smallholder agricultural productivity. We find that different measurement methods from different EO sources: findings are not robust to the choice of EO dataset and outcomes are not simply affine transformations of one another. This begs caution on the part of researchers using these data and suggests that robustness checks should include testing alternative sources of EO data.

econ.GN

Coping or Hoping? Livelihood Diversification and Food Insecurity in the COVID-19 Pandemic

We examine the impact of livelihood diversification on food insecurity amid the COVID-19 pandemic. Our analysis uses household panel data from Ethiopia, Malawi, and Nigeria in which the first round was collected immediately prior to the pandemic and extends through multiple rounds of monthly data collection during the pandemic. Using this pre- and post-outbreak data, and guided by a pre-analysis plan, we estimate the causal effect of livelihood diversification on food insecurity. Our results do not support the hypothesis that livelihood diversification boosts household resilience. Though income diversification may serve as an effective coping mechanism for small-scale shocks, we find that for a disaster on the scale of the pandemic this strategy is not effective. Policymakers looking to prepare for the increased occurrence of large-scale disasters will need to grapple with the fact that coping strategies that gave people hope in the past may fail them as they try to cope with the future.

econ.GN

Privacy Protection, Measurement Error, and the Integration of Remote Sensing and Socioeconomic Survey Data

When publishing socioeconomic survey data, survey programs implement a variety of statistical methods designed to preserve privacy but which come at the cost of distorting the data. We explore the extent to which spatial anonymization methods to preserve privacy in the large-scale surveys supported by the World Bank Living Standards Measurement Study - Integrated Surveys on Agriculture (LSMS-ISA) introduce measurement error in econometric estimates when that survey data is integrated with remote sensing weather data. Guided by a pre-analysis plan, we produce 90 linked weather-household datasets that vary by the spatial anonymization method and the remote sensing weather product. By varying the data along with the econometric model we quantify the magnitude and significance of measurement error coming from the loss of accuracy that results from protect privacy measures. We find that spatial anonymization techniques currently in general use have, on average, limited to no impact on estimates of the relationship between weather and agricultural productivity. However, the degree to which spatial anonymization introduces mismeasurement is a function of which remote sensing weather product is used in the analysis. We conclude that care must be taken in choosing a remote sensing weather product when looking to integrate it with publicly available survey data.

econ.GN

Estimating the Impact of Weather on Agriculture

This paper quantifies the significance and magnitude of the effect of measurement error in remote sensing weather data in the analysis of smallholder agricultural productivity. The analysis leverages 17 rounds of nationally-representative, panel household survey data from six countries in Sub-Saharan Africa. These data are spatially-linked with a range of geospatial weather data sources and related metrics. We provide systematic evidence on measurement error introduced by 1) different methods used to obfuscate the exact GPS coordinates of households, 2) different metrics used to quantify precipitation and temperature, and 3) different remote sensing measurement technologies. First, we find no discernible effect of measurement error introduced by different obfuscation methods. Second, we find that simple weather metrics, such as total seasonal rainfall and mean daily temperature, outperform more complex metrics, such as deviations in rainfall from the long-run average or growing degree days, in a broad range of settings. Finally, we find substantial amounts of measurement error based on remote sensing product. In extreme cases, data drawn from different remote sensing products result in opposite signs for coefficients on weather metrics, meaning that precipitation or temperature draw from one product purportedly increases crop output while the same metrics drawn from a different product purportedly reduces crop output. We conclude with a set of six best practices for researchers looking to combine remote sensing weather data with socioeconomic survey data.

econ.GN

Recent Developments in Inference: Practicalities for Applied Economics

We provide a review of recent developments in the calculation of standard errors and test statistics for statistical inference. While much of the focus of the last two decades in economics has been on generating unbiased coefficients, recent years has seen a variety of advancements in correcting for non-standard standard errors. We synthesize these recent advances in addressing challenges to conventional inference, like heteroskedasticity, clustering, serial correlation, and testing multiple hypotheses. We also discuss recent advancements in numerical methods, such as the bootstrap, wild bootstrap, and randomization inference. We make three specific recommendations. First, applied economists need to clearly articulate the challenges to statistical inference that are present in data as well as the source of those challenges. Second, modern computing power and statistical software means that applied economists have no excuse for not correctly calculating their standard errors and test statistics. Third, because complicated sampling strategies and research designs make it difficult to work out the correct formula for standard errors and test statistics, we believe that in the applied economics profession it should become standard practice to rely on asymptotic refinements to the distribution of an estimator or test statistic via bootstrapping. Throughout, we reference built-in and user-written Stata commands that allow one to quickly calculate accurate standard errors and relevant test statistics.

econ.EM

Differentiation in a Two-Dimensional Market with Endogenous Sequential Entry

Previous research on two-dimensional extensions of Hotelling's location game has argued that spatial competition leads to maximum differentiation in one dimensions and minimum differentiation in the other dimension. We expand on existing models to allow for endogenous entry into the market. We find that competition may lead to the min/max finding of previous work but also may lead to maximum differentiation in both dimensions. The critical issue in determining the degree of differentiation is if existing firms are seeking to deter entry of a new firm or to maximizing profits within an existing, stable market.

econ.GN

Risk, Agricultural Production, and Weather Index Insurance in Village India

We investigate the sources of variability in agricultural production and their relative importance in the context of weather index insurance for smallholder farmers in India. Using parcel-level panel data, multilevel modeling, and Bayesian methods we measure how large a role seasonal variation in weather plays in explaining yield variance. Seasonal variation in weather accounts for 19-20 percent of total variance in crop yields. Motivated by this result, we derive pricing and payout schedules for actuarially fair index insurance. These calculations shed light on the low uptake rates of index insurance and provide direction for designing more suitable index insurance.

econ.GN