Lockdowns vesus contact tracing

Mulligan, Murphy, and Topel* have a thoughtful policy piece on "Some basic economics of COVID-19 policy." It combines a number of economic concepts (e.g., fixed costs versus marginal costs, option value, externalities, capital depreciation (physical and human)). Essentially, it compares the relative strengths of the policy alternatives of Large-Scale Social Distancing (LSSD) versus Screen, Test, Trace and Quarantine (STTQ). From their summary:

Our analysis indicates that the features of a cost-effective strategy will depend on both current circumstances and how we expect the pandemic to play out. Some elements are common, such as the desire to use STTQ rather than LSSD when infection rates are low, and shifting the incidence of disease away from the most vulnerable. These apply whether the objective is to buy time, manage the progression of the disease, or limit the long-run impact of a pandemic that will run its course. The key difference in terms of the optimal strategy is whether our focus is on keeping the disease contained. If the objective is to buy time, then our analysis favors early and aggressive intervention. This minimizes the overall impact and allows for strong but scalable measures via STTQ. In contrast, limiting the cumulative cost of a pandemic that will ultimately run its course argues for aggressive policies later, when they will have the biggest impact on the peak load problem for the health-care system and when they will have the greatest impact on the ultimate number infected. Given the desire to protect the most vulnerable, this objective can even argue for allowing faster transmission to those that are less vulnerable, which further limits the burden on the vulnerable and also reduces the burden on the health-care system. Finally, the objective of long-run containment calls for an effective STTQ strategy applied early to keep the overall infection level low. Starting early lowers overall costs and lowers cumulative infections under the long-term containment strategy.

*I was Bob Topel's RA over a quarter century ago.