The 2014-2015 Legionnaires' disease (LD) outbreak in Genesee County, MI, and the outbreak resolution in 2016 coincided with changes in the source of drinking water to Flint's municipal water system. Following the switch in water supply from Detroit to Flint River water, the odds of a Flint resident presenting with LD increased 6.3-fold (95% CI: 2.5, 14.0). This risk subsided following boil water advisories, likely due to residents avoiding water, and returned to historically normal levels with the switch back in water supply. During the crisis, as the concentration of free chlorine in water delivered to Flint residents decreased, their risk of acquiring LD increased. When the average weekly chlorine level in a census tract was <0.5 mg/L or <0.2 mg/L, the odds of an LD case presenting from a Flint neighborhood increased by a factor of 2.9 (95% CI: 1.4, 6.3) or 3.9 (95% CI: 1.8, 8.7), respectively. During the switch, the risk of a Flint neighborhood having a case of LD increased by 80% per 1 mg/L decrease in free chlorine, as calculated from the extensive variation in chlorine observed. In communities adjacent to Flint, the probability of LD occurring increased with the flow of commuters into Flint. Together, the results support the hypothesis that a system-wide proliferation of legionellae was responsible for the LD outbreak in Genesee County, MI.

Economists have sought to identify institutions which might fill the gap in household access to credit arising from rationing by formal lenders. Credit unions have been identified as institutions which might use informational and monitoring advantages to fill that gap. Using information on household perceptions of their access to credit, this article analyses the impact of certain credit unions on the access to credit of households in Guatemala. Regression results indicate that credit unions serve markets unserved by formal lenders and that information on household perceptions of their access to credit is important in making inferences about lender lending activities.

Central place theory describes an orderly hierarchy of places, with particular retail services developing for lower-ordered places as they reach a threshold. Yet it is likely that nearby areas could serve simultaneously as a source of demand and a source of competing supply for retail stores in a place. This paper contributes to the understanding of local economic development by modeling and estimating the geographic interdependence between a place and its neighboring areas. The simultaneous equation Tobit results suggest that such geographical interdependence exists for most retail industries, with spatial competition on the supply side being particularly important. Copyright 2002 Blackwell Publishers Inc.

Simon Kuznets hypothesized that inequality in a country's distribution of income worsens in the early stages of its economic development and that the inequality improves as the country reaches higher stages of development (the 'inverted U hypothesis'). Empirical support for the inverted U hypothesis has been mixed. In testing Kuznets hypothesis, analysts have specified a variety of parametric forms for the relationship between inequality and development, including a quadratic form (a second-degree polynomial). Using data on income distributions on Native American reservations in the USA, the present analysis indicates that non-parametric estimates of the relationship can inform a parametric analysis. Specifically, while a regression with a second-degree polynomial finds mixed support for the hypothesis, the non-parametric analysis suggests the presence of such an inverse relationship. Indeed, the non-parametric form suggests that a polynomial of greater degree might better capture the relationship between economic development and income inequality. Hypothesis testing supports estimating a fourth-degree polynomial rather than a second-degree polynomial. All terms in the fourth-degree polynomial are statistically significant and the estimated coefficients support the Kuznets hypothesis. These regression results counsel caution in testing the inverted U hypothesis by estimating only parametric forms which produce strictly concave functions.

Mushinski and Weiler (2002) updated a vein of rural economic geography literature by estimating empirically the importance for retail development of geographic interdependencies between places and their neighboring areas. This note extends interpretation of their empirical results by considering the influence of neighboring areas and establishments on retail thresholds in a place, and the policy and economic development implications of their results. This note discusses the nature of spatial competition and considers how retail establishments might act as regional base industries, absorbing shopping flows from outlying residents in a fashion similar to traditional export industries. Moreover, it signals that understanding geographic interdependencies is important for economic development planning, and suggests there may be merit in more regional coordination of retail firm recruitment in relatively small and/or isolated rural areas.