This paper and its sequel consist of a series of models or examples, each trying to explain the possibility of non-Walrasian wage rates and involuntary unemployment equilibrium. In recent years there have been many attempts to explain the possibility of equilibrium wages at non-market clearing levels with involuntary unemployment. There are the wage efficiency models (Yellen, I984), contract models, bargaining models (e.g. Shaked and Sutton, I984) to name but a few. The common feature of these models and the ones I shall discuss is that involuntary unemployment (for a certain range) does not lead any agent to change his behaviour. My models as in the works of Lindbeck and Snower (I985, I986) are based on the distinction between insiders and outsiders. In my models, however, workers and firms live for more than one period, and as a result they may follow norms which are not in their short-term interest but are rational in the longrun. I shall model the labour market in a repeated game framework. The literature on repeated games in recent years has shown that in general there are a large number of equilibria (see Fudenberg and Maskin, I986). A major application of repeated games has been to the industrial organisation literature, where it has been shown that many types of behaviour on the part of firms (e.g. collusion, predatory pricing) can be supported as equilibria of the game (see Fudenberg and Tirole, I984). My models, which are applications of the repeated game to the problems of insiders and outsiders, also contain many equilibria. The Walras-ian outcome is one of the possible resulting equilibria; there are also others. The equilibria that I shall discuss, however, are those which may help us to understand some stylised facts and at the same time generate non-Walrasian outcomes. I shall try to show that, for some levels of unemployment, each insider may rationally choose strategies which deter firms from trying to push the wages down and/ or deter unemployed from under-cutting. In this paper, I shall define insider's as those who follow the norm. If an insider deviates from the norm, he loses his insider position. The firm(s) agree(s) to pay higher wages than the market clearing rate because the insiders threaten to go on strike if the firm tries to force down the wages of any one of them and there are not enough unemployed workers to replace all insiders. Moreover, the threat of each insider turns out to be credible because, if he does not follow the norm, he will lose his insider status and will not be protected by other insiders in the next period and thus will be at the mercy of the firm. Therefore, in this paper the non-Walrasian outcomes are the result of the firm