This dissertation investigates the economic impact of global accounting harmonization. Particularly I focus on its influence on macro level cross-border M&A investments. I posit that mandatory IFRS adoption lowers the systemic information noise embedded in countries' accounting standards. This reduces the associated information processing costs and enhances the economic role accounting standards play on cross-border M&A flows. After mandatory IFRS adoption, a 1% increase in accounting standards disparity suppresses bilateral M&A flows by around 2%; decrease in accounting standards disparity helps promote bilateral M&A flows when paired countries' governance infrastructure gap is relatively wider. I do not find these associations significant prior to mandatory IFRS adoption. Overall, this dissertation documents an evolving economic role accounting standards play on bilateral cross-border M&A flows, and supports International Accounting Standards Board's advocacy in adopting a uniform set of accounting standards globally. Moreover, it further analyses the current adoption demand for IFRS from the U.S. firms.