Based on the information provided, it can be inferred that Reaganomics had a complex impact on the American economy. Specifically, the statement that "Reaganomics initially caused a recession but ultimately contributed to economic growth" suggests that while there were short-term negative effects, the policies eventually led to a recovery and positive economic outcomes.
The other statements, such as "Reaganomics immediately led to a period of sustained economic growth" and "Reaganomics had no significant impact on the economy," contradict the notion of an initial recession, while the statement about increased government spending needs further context, as Reagan's policies often involved tax cuts rather than significant increases in spending.
In summary, the most accurate inference is that Reaganomics faced initial challenges leading to a recession but ultimately played a role in facilitating economic growth.