Basically, I think this statement from a commenter, which Roger endorses, is nonsense:
Think of it this way. With a centralized labor market, the real wage is pinned down by the intersection of labor demand and supply. With search, the labor market need not clear: the labor supply FOC is missing, and we need to add something else to close the model. One thing to add is an explicit bargaining model that effectively pins down the wage. An alternative is to say that output is demand-determined, and that the wage is the marginal product of labor at the demand determined level of output. Then firms are on their labor demand curve, but workers are not on their labor supply curve (but the beauty of search - unemployed workers will take a job at any positive wage).Roger's model is internally consistent and coherent. In equilibrium everyone is optimizing. There is no notion of output being "demand determined" or some people being on demand curves while others are off supply curves. That language did not help me. It just made me confused. Roger may think it helps him, but I think not.
Roger's model is very nice, as it can capture the essence of Keynes (new or old) in a very simple and clean way. It is a bit of a chicken model though.