というNBER論文(原題は「Who Set Your Wage?」)をデビッド・カード(David Card)が上げている。内容は今年1/8のAEA会長講演で話したもので、以下はその要旨。

I discuss the recent literature that has led to new interest in the idea of monopsonistic wage setting. Building on advances in search theory and in models of differentiated products, researchers have used a number of different strategies to identify the elasticity of firm-specific labor supply. A growing consensus is that firms have some wage-setting power, though many questions remain about the sources of that power.


In the textbook model of labor markets – synthesized by Hicks (1932) – product and factor markets are perfectly competitive and wages are equated to marginal products. Just one year after Hicks, Robinson (1933) developed an alternative framework for understanding firm‐specific wage setting and coined the term “monopsony”. The book attracted a lot of attention, and at least some labor economists were enthusiastic. Reynolds (1946, p. 390) wrote that the concept of an upward‐sloping supply curve of labor to the firm “… has made its way rapidly into the textbooks and seems well on its way to being generally accepted as a substitute for the horizontal supply curve of earlier days”. But Reynolds’ prediction was premature. By the 1960s the concept of monopsony had been relegated to discussions of company towns. Indeed, in the preface to the second edition to her book, Robinson (1969) observed: “All this had no effect. Perfect competition, supply and demand… and marginal products still reign supreme in orthodox teaching.”
At the risk of following too closely in Reynolds’ footsteps, in this paper I will try to make the case that the time has come to recognize that many – or even most – firms have some wage‐setting power. Such a shift was made with respect to firm’s price‐setting power many decades ago. Economists now routinely accept that the prices of products like gasoline, breakfast cereal, and ketchup are set with some degree of market power, even in on‐line markets. In the past few years we may have reached a tipping point for a similar transition in labor economics, driven by the combination of new (or at least post‐1930) theoretical perspectives, newly available data sources, and accumulating evidence on several different fronts.
ヒックス(1932*1)がまとめた労働市場の教科書モデルでは、製品と要素の市場は完全に競争的で、賃金は限界生産力と等しくなる。ヒックスのちょうど1年後、ロビンソン(1933*2)は企業固有の賃金設定を理解するための別の枠組みを構築し、「買い手独占」という用語を作り出した。同書は大いに注目を集め、少なくとも一部の労働経済学者は熱狂した。レイノルズ(1946、p. 390*3)は、企業における労働の右上がりの供給曲線の概念は「…急速に教科書に普及し、以前の水平の供給曲線の代わりとして順調に一般に受け入れられる過程にあるように思われる」と書いた。しかしレイノルズの予測は早計だった。1960年代までに買い手独占の概念は企業城下町に関する議論に限られるようになっていた。実際、ロビンソン(1969)は第二版の序説で、「これらすべては効果がなかった。完全競争、需給…および限界生産力は依然として正統派の授業において君臨していた」と述べた。