As Tax Day approaches, many Americans will be making investment decisions for retirement. Conventional wisdom holds that young investors in lower income brackets benefit the most from investing in post-tax retirement vehicles such as Roth IRAs, while older, wealthier investors benefit from tax-deferred investment in accounts like traditional 401(k) plans and IRAs. New research from the University of Missouri reveals the best investment strategy for most individuals isn’t one or the other—it’s both.