Employers wishing to file an application for alien labor certification (a PERM process) may always consider obtaining more than one opinion about legal issues.
There are so many unresolved questions of law involved in immigration cases, that different minds can easily reach different conclusions.
Consider that a PERM application and residency application involve several different bodies of administrative rules -- the Department of Labor, the USCIS, and often the Department of State (for processing at the U.S. Consulate Abroad).
One of the problems that frequently arises is that government agencies do not use the same standard. For example, with reference to H-1B petitions, the USCIS has a standard to determine education and experience equivalencies for Bachelor's Degree which allows a substitution of experience for one year of college education, using the formula 3-1 (three years of experience equal one year of college education), however the DOL uses a standard of Specific Vocational Preparation that allows 1-1 (each year of specific vocational preparation is equal to the other, regardless of whether the preparation is education, training or experience.
Another difference between H-1B petitions and PERM is that the H-1B petitions are fashioned to bring a specific alien to work in the U.S. for a limited period of time, and the Employer must prove that the alien has a Bachelor's Degree or higher, and will work in an occupation that requires the attainment of a Bachelor's Degree. Additional qualifications, such as language skills, supervisory experience, or knowledge of specialized technology are up to the discretion of the employer. However, when applying for PERM, employer preferences are not permitted and must be justified by business necessity or other forms of documentary evidence.
Questions also abound regarding preference classifications. The DOL process for PERM labor certifications is not coordinated with the DHS preference classification system. In the past, discrepancies have been noted in the treatment of issues such as degree requirements, equivalencies vaguely stated (where employer lists "or equivalent" without further clarification), special requirements and conditions, details regarding training, part-time vs. full-time employment, names and places of employment documenting alien's experience, incomplete or partially completed histories of employment, and others.
Experience with alien employment certification will certainly vary depending on the region or state in which the employer or the employer's attorney has had prior experience. Prevailing Wage Determinations are now done by the U.S. Department of Labor, but until 2010 they were done by the State Workforce Agencies in a widely diverse manner, so that the determination of wage levels or ranges would be entirely different. I remember a case where an Economist filed in one state (requiring only a Bachelor's Degree) resulting in a Wage Level One (the lowest age), and a substantially similar application filed in another state resulted in Wage Level Four )the highest wage)!
Availability of US labor also varies from state to state and from region to region. In some parts of the U.S., there is a scarcity of labor to fill specific jobs (even in these difficult times) while in other areas workers are readily available.
Complex legal, ethical and evidentiary issues also confuse employers due to the fact that the Department of Labor often uses a "totality of the circumstances" approach to weigh documentary evidence, while the USCIS tends to use more bright line tests based on precedent decisions. Many employers and attorneys do not even realize that the DOL decisions, enunciated by the Board of Alien Labor Certification Appeals, are not precedent decisions at all, since DOL has never instituted a system of precedent decisions with its Administrative Law Judges.
The DOL also seems to have more unpredictability than the USCIS, not only for the lack of precedent decisions, but because the entire PERM process is controlled in an environment designed to protect US workers, while the USCIS regulations are intended to provide benefits and opportunities for aliens to enter the U.S. to study, work and reside side-by-side with U.S. citizens.
All in all, even the most experienced employers and legal representatives can have different opinions about labor certification issues, and the best remedy is to consider more than one opinion when preparing to file a PERM case.