Three Essays on Parsimony and Scientific Approaches to Decision-Making

Entrepreneurs instinctively add—features, market segments, hypotheses—yet cognitive research shows that people systematically overlook value-creating subtractions. This dissertation advances the thesis that causal and parsimonious theories of value are a powerful driver of venture performance. Three complementary studies underpin the argument. Chapter I reports a field randomized controlled trial with 254 Italian founders: theory-based training raises the likelihood of subtractive changes by 20.7 percentage points over control and accelerates first revenues. Chapter II develops a formal model that endogenizes optimal theory complexity: under bounded rationality and correlated cues, entrepreneurs balance the marginal informational value of adding new factors and their additional cognitive cost, formalizing the concept of parsimonious theorizing. Chapter III pools eight field RCTs covering 1,556 startups in eight countries: ventures trained to craft lean causal theories grow sales 1.3x-1.7× faster and terminate unviable projects sooner than both evidence-only and control groups. Together, the papers integrate the subtraction neglect bias from psychology with the theory-based view of strategy, demonstrating that parsimony is a rational, generalizable, and managerially actionable pathway to superior entrepreneurial outcomes. Beyond scholarly contributions, the findings guide accelerators and investors: teach founders to articulate novel causal theories, encourage the removal of superfluous features, and monitor subtraction as an early indicator of disciplined opportunity pursuit.