This study considers the market of potatoes in Amazonas, Peru from an informal production sector to a more formal retail-marketing sector. I consider and challenge current understandings that attempt to model formal/informal markets sectors. Those include state involvement in economic processes, wage structure and social security mechanisms, and size and organizational techniques. As, well I suggest that the method of transfer would be a useful addition to the work that attempts to model and define formal and informal economic sectors. I do so because of the importance of trust in economic exchange. In this study, these four models are reframed in terms of hypotheses to see which can most systematically explain increased formality along the market channel from production to retail marketing. I find that only two can. Those are state involvement and method of transfer and trust. Research methods include open-ended interviews (n=25) and participant observation.