This dissertation comprises three essays that investigate how grocery prices shape market outcomes, retailer behavior, and households in the United States. Across these essays, I examine grocery prices as a primary economic mechanism by which policy shocks, firm incentives, and household constraints are transmitted along the food value chain. The first essay examines the incidence of county-level grocery sales taxes on retail food prices, food retail worker earnings, and farmgate milk prices (an upstream farm output price measure) from 2010 to 2019. Using a newly assembled panel of county grocery tax rates merged with NielsenIQ Homescan transaction data, I estimate the pass- through of grocery taxes to consumer food prices across a broad range of products. I document substantial tax over-shifting: on average, a grocery tax that generates one dollar of tax revenue raises tax-inclusive food prices by about $1.44. The burden is especially large for lower-income households, shoppers at discount and dollar stores, and buyers of perishable staple products such as fluid milk. I then use farmgate milk prices as a tractable upstream case to test whether grocery tax incidence extends beyond retail markets, motivated by the especially strong over-shifting observed for fluid milk. I find that the higher retail margins implied by this over-shifting are not associated with higher earnings for food retail workers or higher farmgate milk prices, suggesting that the gains do not flow upstream to workers or farmers. The second essay explores how local retail food prices affect the volume of food donations from grocery retailers to food pantries. Combining transaction-level donation records from a regional food bank with category-specific food price measures, I estimate how changes in food prices shape retailers’ donation behavior. The results show a negative relationship between food prices and donated pounds: when food prices are higher, retailers donate less food. This pattern is consistent with the idea that food donations respond not only to charitable motives, but also to market incentives that affect the opportunity cost of donating rather than selling near-expiry inventory. Additional analyses show that this relationship is robust across a range of specifications. The third essay exploits linked administrative records from SNAP and food pantry systems, together with a locally constructed grocery price index derived from Circana retail scanner data, to estimate how local grocery price fluctuations shape households’ joint use of public and private food assistance in upstate New York. Higher local grocery prices are associated with more pantry use, slightly higher SNAP participation, and faster within-month SNAP benefit exhaustion. However, the implied changes in household behavior at observed rates of price growth are small in absolute terms. The results suggest that short-run grocery price fluctuations move food assistance use in the expected direction, but are not, on their own, a dominant driver of household behavior in this setting. These essays provide a unified perspective on the economic role of grocery prices in the United States. By tracing the incidence of price shocks through retail competition, private charitable supply, and public food assistance programs, this dissertation underscores the pivotal role of grocery pricing in mediating the relationship between market forces and the welfare of vulnerable populations. More broadly, the dissertation highlights grocery prices as an important link connecting food markets, redistribution, and household well-being.