This study evaluates consideration to allow shipments of Argentine fresh lemons into the United States. Besides providing analysis of an on-going and still disputed systems approach, this case was viewed as a relevant test for feasibility of a prototype analytical tool that links economic and risk assessment for SPS measures. Political economy and empirical assessment shows that despite some apparent similarities among systems approach policies, the idiosyncratic nature of SPS issues limits application of a common quantitative method for such policies. Assessment within context of the lemon case reveals important lessons with respect to economic analysis. Scientific debate is likely to be more contentious and sustained in cases where the political stakes are greater, thus a priori economic evaluation is likely to be the most limited in those cases where it could prove the most valuable. Results highlight transitions in the political reality of WTO SPS agreement applications. Movement away from specificity in risk assessment limits common understanding and further assessment of regulatory policies. The dynamics of the lemon case shifted attention to credibility of domestic, as well as foreign, institutions. Confidence between regulatory agencies is important, but does not compensate for public trust.