I describe household behavior in boom and bust economic cycles with a particular focus on the recent financial crisis. The behaviors are motivated by cognitive limitations and psychological bias. In boom times, households’ extrapolation bias and groupthink lead to chasing and extending asset bubbles (like tech stocks and real estate). Increasing use of debt spurs the economy and eventually overburdens households. In bust times, the biases and fear lead to selling previously popular assets at low prices. Households generally respond to bust times by spending less, repaying debt and saving more, which drags on an already slow economy. In addition, households influence businesses and governments into actions during the cycle. In the recent boom, predatory lenders preyed on cognitive limitations and biases of subprime borrowers to sell them high cost mortgages that they would not be able to repay. Another contributing factor is that during boom times, household attention is not focused on financial regulation. This is when business influences the political process and laws are enacted to loosen market regulation. These changes may extend the boom period into bubble territory. During bust times, public outcry influences politicians to tighten business regulation, likely inhibiting the economic rebound. Thus, household behavior plays an important role in economic boom/bust cycles.