The NY Post says that they’ve found a correlation between economic growth and same store sales at Walmart. Their theory is that as the economy improves, people run away from the big blue box.

Bentonville, Ark.-based chain is likely to post, for the first time in its history, four straight quarters of same-store sales drops. Coincidentally, the S&P 500 Index is up in each of those quarters.

It’s an odd relationship America has had recently with the low-price titan.

Research by The Post shows that in all but two of the last 13 quarters, Wal-Mart’s US same-store sales dropped whenever the S&P showed a gain — and vice versa.

The latest decline in same-store sales must be particularly frustrating for the chain’s executives — including Bill Simon, the head of US stores — because it is coming after the chain poured $1.17 billion into its massive “Save Money, Live Better” advertising campaign in the last three months of 2009 alone.

As marts rise, Wal-Mart’s US stores fall [NYP]

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.