Is Unemployment a Macroeconomic Problem
通过类比机场闲置时间，分析失业的微观特征，如闲置时长分布和人口集中度，探讨失业是否应被视为宏观经济问题。
Rather than start directly on the sensitive issue of the economic role of unemployment, I would like to spend some time first on a parallel question of rather less social importance, and then draw some analogies to the problem of unemployment. The phenomenon I will examine is the time people spend idle at airports. Ultimately, I will compare the analysis of idle airport time with the analysis of idle time in the labor market. In any airport at any time, numerous people are waiting for something to happen. These people are not doing anything particularly constructive with their time-they are waiting because they arrived early, because their planes have been delayed, or because they are in a queue for the next available flight. An observer who knew nothing about the purpose of an airport would be puzzled by the chronic idleness of most of the people there. The observer might gather data on airport idleness along the following lines. At any given time, 0.2 percent of the population is idle at the airport. The idle population turns over frequentlythe median duration of a spell at the airport is 35 minutes. But long spells account for the bulk of idleness-half of all idleness occurs in the course of spells which will last 5 hours or more. Airport idleness is highly concentrated in the population. In a given year, three-quarters of the population are never idle at the airport; 5 percent of the population incurs half of all idleness. A predictable seasonal pattern is apparent-idleness reaches sharp peaks at Thanksgiving, Christmas, and Easter, plus a broad peak in the summer. Were it quantitatively more significant, airport idleness would be a social issue. The airport idle are not usually engaged in useful activities. Few of them spend time trying to locate earlier flights, nor do many of them try to accelerate their movement by offering to pay a higher fare. A surprisingly large fraction do nothing more than sit. The opportunity cost of time spend idle at the airport is essentially zero, it would appear.