Presidents like to take credit for good economic performance. If there are lags in policies, explain why presidents may not deserve all the credits (or blame) for economic policies.

First, President's don't deserve all of the credit from economic booms since the framework for that growth was likely set before they even got into office. A policy enacted in one administration may not begin to impart real change until the next. Also, Presidential policy is arguably not a major factor in macroeconomic trends. I would suggest that the natural cyclical trends in the economy and policies put forth by the Fed are much more influential on economic health.