How Policy Shapes Competition: Early Railroad Foundings in Massachusetts
研究了三种政策（公共资本化、支持卡特尔、反垄断）对市场竞争和新企业创立的影响，通过分析1825-1922年马萨诸塞州铁路创立数据，发现公共资本化增加创立数量，支持卡特尔政策也增加创立数量，而反垄断政策则抑制创立。
To examine the effects of policy on markets and competition we outline hypotheses about the effects of three common policy regimes--public capitalization, pro-cartel, and antitrust--on competition and the founding of new firms. Analyses of Massachusetts railroad foundings between 1825 and 1922 show that public capitalization raises the number of foundings by increasing available resources, pro-cartel policies raise the number of foundings by dampening competition from incumbents, and antitrust depresses foundings by stimulating competition. Ecological factors only show the expected effects once policy is controlled. Industrial organization factors show no net effects. We argue that public policy establishes the ground rules of competition and thus creates varieties of market behavior.