Espinosa's research combines theoretical approaches and qualitative methodologies from sociology and the humanities to study the intersection of migration, arts and culture from a transnational perspective.

Before earning his doctoral degree in sociology from Northwestern University, Espinosa conducted ethnographic work with Mexican families in both sending communities and in the United States for the Mexican Migration Project. He also worked as an ethnographer for projects that gave him the opportunity to explore the life and struggles of gay men, lesbians and intravenous drug users (Medical College of Wisconsin) and poor Latinx families on welfare (University of California, Los Angeles). Espinosa directed a project for the Heartland Alliance for Human Rights and Human Needs that helped empower immigrant grassroots organizations in Chicago. His research led to the publication of a policy report that hometown associations used to reach institutions that supported community development in Mexico.

Espinosa's first book, El Dilema del retorno (El Colegio de Michoacán), analyzes the gender negotiations over the dilemma of settlement and return to study how both gender and community identity are embedded in cultural practices within transnational social contexts. His second book, Martín Ramírez: Framing his Life and Art (University of Texas Press), is a thick reconstruction of the singular yet paradigmatic trajectory of an undocumented Mexican migrant and self-taught artist who produced all his artwork inside a California psychiatric institution during the 1950s. Besides exploring the intersection of art and migration, Espinosa analyzes the politics of artist recognition and commodification of works produced by marginalized creators in order to illuminate how hierarchies and artistic singularity are reproduced in the contemporary art world.

His most recent project on representations of migrant suffering is based on ethnographic work conducted with undocumented migrants from Central America in transit through Mexico. Performances of Suffering in Latin American Migration: Heroes, Martyrs and Saints (forthcoming Palgrave Macmillan) is a collaborative project with Ohio State performance studies scholar Ana Elena Puga that combines historical, sociological analysis and a theater/performance studies lens to understand how migrant suffering is framed and staged (by migrants, activists, artists and advocates) in order to claim human rights for undocumented migrants.

In the curatorial field, Espiniosa's work on the intersection of arts and migration has given him the opportunity to participate in exhibitions and art catalogues that promote the artistic work produced by migrants, Latinx artists and contemporary artists impacted by migrant suffering.