Since Schumpeter's 1942 classic treatise Capitalism, Socialism, and Democracy, there have been dozens of academic writings on the relationship between firm size and innovative capacity. While most scholars agree on the positive relationship, it is also clear that deep caveats exist. Whether or not a firm is innovative or inventive has a lot to do with size, but also the industry to which the firm belongs, the firm's degree of productivity, and overall R&D "intensity" (a measure of R&D as a percent of spending or sales). Moreover, the measurement used within these studies matters as well (fixed vs. random effects, etc.). One thing is evident though, tech companies these days are investing an increasingly higher amount of dollars into R&D irrespective of downturns in their overall revenues.
The second critical issue I consider is whether or not R&D spending directly correlates with innovation. It may seem obvious that for a firm to ponder, produce, and perfect technological innovations, they must invest R&D dollars. However, to what degree does investment stimulate innovative thinking and what about the quality of that thinking? As reflected upon in the article, Steve Jobs pushed back against the consensus opinion that R&D dollars spent clearly leads to innovation. It is a matter of perspective. If a firm wishes to see R&D investment through to commercialization, the correlation will be very clear. But, can zero R&D dollars spent still result in creative, inventive, and innovative thinking? The answer is unequivocally yes.