My PhD thesis consists of 4 papers that analyse uncertainty, specifically trade policy uncertainty, by examining its best measurement and its impacts on firms’ international and domestic operations.

The first paper, “Improving the Trade Policy Uncertainty Index”, studies how best to measure trade policy uncertainty. I show that Baker et al.’s (2016) and Caldara et al.’s (2020) newspaper-based Trade Policy Uncertainty (TPU) indices misclassify and omit a substantial number of articles. I use a new set of search terms to construct an improved TPU index for the U.S. from 1987 to 2023 and provide a detailed mapping between major trade policy events in the U.S. and the new index.

The second paper, “The Effects of Trade Policy Uncertainty on Exporters and Multinational Firms”, is a theoretical paper examining the effects of trade policy uncertainty on the entry and exit of exporters and multinational enterprises (MNEs) in foreign markets. In this paper, I use a two-country DSGE model, where export and MNE continuation costs are lower than entry costs, to analyse the macroeconomic effects of a shock to trade policy uncertainty.

In the third paper, “Panic at the Costco: Buffer Stock under Uncertainty”, I build a Small Open Economy model where a distributor keeps buffer stock inventories for the household and producers, and inventory is driven by a preference shifter that depends on the available stock à la Görtz et al. (2022).

The fourth paper, “The Volatility of Economic Policy Uncertainty”, is joint work with Prof. Paul Kattuman, where we analyze the volatility of uncertainty, measured using Baker et al.’s (2016) newspaper-based Economic Policy Uncertainty index, in a T-GARCH framework. We then examine the spillovers in both the level and volatility of economic policy uncertainty across countries from 1997 to 2023.