Security trading now fragments into more than ten almost identical stock exchanges in the United States. We show that discrete pricing is one economic force that prevents the consolidation of trading volume. The uniform one-cent tick size (minimum price variation), imposed by the SEC's Rule 612, leads to more dispersed trading for lower priced securities. When a security reverse splits, its price increases and relative tick size (one cent divided by the price) decreases. We find that reverse splits consolidate trading of securities, using securities with identical underlying fundamentals that do not reverse split as the control group.

Rainfall measures may be imperfect proxies for floods, given factors such as upstream water balance, proximity to rivers, and topography. We check the robustness of flooding-migration relationships by combining nationally-representative survey data with measures of flooding derived from weather stations, gridded products, and remote sensing tools. Linear probability models reveal that extreme flooding is negatively associated with out-migration. Rainfall-based proxies produce results qualitatively similar to those using the satellite-based measure of inundation, but only the latter is able to discern non-monotonic effects throughout the distribution. Moreover, estimates differ widely across areas, suggesting that households respond differently to rainfall and flooding.