Wage Indexation and Discretionary Monetary Policy
构建模型分析工资指数化对通胀和福利的影响，发现指数化既有降低通胀成本（推高通胀）又有陡化菲利普斯曲线（抑制通胀）的双重效应，净效果需通过结构模型确定。
Since the early 1970's, both academic researchers and policymakers have devoted considerable attention to the macroeconomic effects of wage indexation. However, these two groups have focused on different effects. Starting with Jo Anna Gray (1976) and Stanley Fischer (1977a), formal models emphasize the role of indexation in stabilizing or destabilizing output. In contrast, informal policy discussions usually focus on the allegation that indexation is inflationary (e.g., Arthur Okun, 1971; Mario Simonsen, 1983; Eliana Cardoso and Rudiger Dornbusch, 1987). To reduce this gap, this paper presents a model of the effects of indexation on inflation and asks whether indexation raises economic welfare when these effects are taken into account. Until recently it was difficult to formalize the argument that indexation is inflationary, because economists lacked models of the sources of inflation. This paper applies the insight of Robert Barro and David Gordon (1983a) that, with discretionary policy, the employment gains from surprise inflation tempt the monetary authority to create positive trend inflation. As stressed by Fischer and Lawrence Summers (1989), policies that reduce the costs of inflation, such as indexation, cause Barro-Gordon policymakers to choose higher inflation. Indeed, inflation can rise so much that welfare falls despite greater protection against inflation. This effect is appealing because it captures the common argument that indexation weakens policymakers' will to fight inflation.1 This is not the end of the story, however, because wage indexation has a second effect: it reduces the employment effects of surprise inflation. That is, unlike most policies to reduce the costs of inflation, such as indexation of interest rates, wage indexation steepens the Phillips curve. In the BarroGordon model, a steeper Phillips curve reduces the temptation to inflate and hence reduces equilibrium inflation. Since indexation has one inflationary effect (lower costs of inflation) and one anti-inflationary effect (a steeper Phillips curve), the net effect appears ambiguous. Even if the net effect on inflation is determined, the welfare effect may remain unclear: if inflation rises, the welfare loss might or might not be outweighed by the lower cost of a given amount of inflation.2 These ambiguities cannot be resolved with the Barro-Gordon model alone, because the Phillips curve and the effect of inflation on welfare are ad hoc. It is plausible that indexation affects these relations, but the relative strengths of the effects are unclear. Resolving the ambiguities requires a more structural model in which the effects of indexation are derived, rather than assumed. This paper studies such a model; specifically, we use a model of staggered wagesetting based on Gray (1976), Fischer (1977a, b), and John Taylor (1980). The degree of indexation is an explicit parameter, and so we can derive its net effects on inflation and welfare. Section I of this paper presents our basic model and derives equilibrium inflation in