They are ubiquitous in many of our communities and an integral part of our Los Angeles and national economy. On a daily basis, day laborers, or jornaleros as they’re known in Spanish, gather by the thousands in public markets to search for temporary employment in the construction, moving and landscaping industries.

But extreme groups such as the Minutemen vigilantes have unfairly targeted them as their cause celebre, even though detailed conditions of their work were relatively unknown until last week when several colleagues and I released the findings from the first national study of day labor.

We spoke to over 2,600 workers in 20 states, 139 cities, and 250 hiring sites to obtain a national perspective on this market. During our travels, we confirmed that the distribution of day labor is expansive. Besides Los Angeles and New York, we found day laborers in suburban and rural communities in places like Las Vegas; Atlanta; Raleigh-Durham, N.C., and the Washington, D.C., region. Jornaleros are searching for work where robust economies in housing construction demand on-the-spot, for-hire workers.

Jornaleros assist residential construction contractors and homeowners with ready labor to offset a crewmember who may have called in sick, to transition from one work site to another, or to simply keep labor costs down.

Clearly, the growth of day labor across the United States is driven by labor demand, and while the length of any given assignment is short, usually one day, most jornaleros are able to string together enough assignments to allow them to earn an income, albeit at a level below poverty. Coupled with relatively poor pay are labor violations, which are an all-too-common occurrence in the day-labor market. Wage theft contributes significantly to the meager earnings that day laborers already make with nearly half of all jornaleros reporting nonpayment or underpayment for work they completed in the two months prior to being surveyed.

Day laborers also experience a high incidence of workplace injury. One in five has suffered an injury while on the job and as a result, about two-thirds of these men have missed work. To be sure, day laborers face potentially dangerous work because many are employed in the construction industry which itself has high rates of work-related injury. However, these rates are so high that the inescapable conclusion is that jornaleros are hired to undertake some of the most dangerous jobs at worksites where there is little, if any, meaningful enforcement of health and safety laws.

In many ways, day labor is a paradox. It is both connected and disconnected to the mainstream economy. For example, many day laborers are marginalized and in a vulnerable position because up to 75 percent lack documents, yet are in dire need of earning an income to support themselves and their families. As a result, many day laborers find themselves exposed to the vagaries of a labor market that is rife with violations of basic labor standards, hallmarks of the wider informal economy of which it is a part. At the same time, the day-labor market provides limited pathways for workers to enter the formal, mainstream economy, usually in construction but also in moving and in manufacturing.

The top policy priority is clear: safeguarding, improving and enforcing labor standards in the day labor market, which fills a critical demand from businesses in Los Angeles and elsewhere.

From our study, we learned that worker centers (such as the newly opened one in Burbank) have emerged as the most comprehensive response to the workplace abuses that day laborers endure, as well as to address community tensions that have arisen as a result of workers gathering near residential areas. Fundamental to their value is the ability of worker centers to intervene on both the demand and supply sides of the day-labor market. On the demand side, worker centers monitor the actions of employers, increase the transparency of the hiring process and provide an institutional foundation for holding employers accountable for workplace abuses. On the supply side, they organize and normalize the hiring of day laborers, monitor worker quality and provide opportunities for worker incorporation into the mainstream economy through employment assistance and, in some cases, skills training.

The contributions of worker centers go beyond the day-labor market itself. In the communities in which day laborers work and live, these centers participate as key stakeholders in the resolution of neighborhood conflicts over day labor. Day-labor worker centers deserve our support, not the unfair and emotionally laden criticism of the minutemen and other vigilante groups.

*Abel Valenzuela Jr. is Director of the Center for the Study of Urban Poverty at the University of California, Los Angeles.