Hey sorry, I didn't dispute the credit bit - the real value of debt does increase and assets like houses decrease in value meaning debt cannot be backed by the same collateral - so you need to further explain why credit becomes more expensive (not just deflationary expectations as it is unrealistic to expect deflation to continuously occur without government intervention.)
In the essay, I only disputed the spending bit; however I don't fully agree with the spending in the long-term - here's why.
Consumers will spend more in the short term as there is no way of knowing that deflation will continue and won't delay purchases. However if for some reason they knew that deflation would continue, short-term or long-term spending increase is dependant on a few variables including price elasticity of goods and services, current global and domestic economic conditions, interest rates. In saying that, deflation creates unemployment, which will constrict economic growth levels and decrease national income over a period of time, and thus decrease consumption in the long term.
This is a classic case of theory versus reality, in theory what oliver mentioned is correct, that deflation will lead to reductions in consumption in the short term, however in practice there is no way of knowing prices wont be low even further, so they won't delay purcahses. Although it might be relevant to mention the few variables, it would be a good idea to consider things in certeris paribus, otherwise there would be no way to write any economics essay.!
for more on deflation, just look at what happened to japan!