and Pharmacia in 2003, can occur through 20 or more years, but this presentation provides an alternative view of our performance that is used by management to internally assess business performance. We believe the elimination of amortization attributable to acquired intangible assets provides management and investors an alternative view of our business results by trying to provide a degree of parity to internally developed intangible assets for which research and development costs previously have been expensed.

However, a completely accurate comparison of internally developed intangible assets and acquired intangible assets cannot be achieved through Adjusted income. This component of Adjusted income is derived solely from the impacts of the items listed in the first paragraph of this section. We have not factored in the impacts of any other differences in experience that might have occurred if we had discovered and developed those intangible assets on our own, and this approach does not intend to be representative of the results that would have occurred in those circumstances. For example, our research and development costs in total, and in the periods presented, may have been different; our speed to commercialization and resulting sales, if any, may have been different; or our costs to manufacture may have been different. In addition, our marketing efforts may have been received differently by our customers. As such, in total, there can be no assurance that our Adjusted income amounts would have been the same as presented had we discovered and developed the acquired intangible assets.

Acquisition-Related Costs

Adjusted income is calculated prior to considering transaction, integration, restructuring and additional depreciation costs associated with business combinations because these costs are unique to each transaction and represent costs that were incurred to restructure and integrate two businesses as a result of the acquisition decision. For additional clarity, only transaction costs, additional depreciation and restructuring and integration activities that are associated with a business combination or a net-asset acquisition are included in acquisition-related costs. We have made no adjustments for the resulting synergies.

We believe that viewing income prior to considering these charges provides investors with a useful additional perspective because the significant costs incurred in a business combination result primarily from the need to eliminate duplicate assets, activities or employees––a natural result of acquiring a fully integrated set of activities. For this reason, we believe that the costs incurred to convert disparate systems, to close duplicative facilities or to eliminate duplicate positions (for example, in the context of a business combination) can be viewed differently from those costs incurred in other, more normal, business contexts.

The integration and restructuring costs associated with a business combination may occur over several years, with the more significant impacts ending within three years of the transaction. Because of the need for certain external approvals for some actions, the span of time needed