Most investors are likely familiar with key economic indicators such as the Conference Board’s Index of Leading Economic Indicators, the University of Michigan’s consumer sentiment survey, and the monthly jobs report, among others.

But there are a number of unconventional indicators that garner less attention. For instance, The Economist publishes a Big Mac Index to compare global currency valuations according to what McDonald’s famous hamburger fetches in different countries. There’s also the Hemline Index, which posits that hemlines rise during boom times, while modesty prevails during downturns.

Although some alternative indicators are of dubious value or have ultimately been disproved, most have at least a kernel of truth to them. And over the years, I’ve discovered an alternative indicator of my own.

Each month, we interview several fund managers for our recurring features, including “Insider’s Edge” and “Across the Street.” But it’s rare to simply ring a portfolio manager and have a chat right then. Instead, the time it takes to coordinate an interview is dependent upon numerous factors, such as the time of year, where we are in the economic cycle, and the severity of the latest financial or economic crisis.

On average, there’s a lag of about three days between making initial contact with a fund company and getting a fund manager on the phone. In the summer, this process can take as long as a week, as fund managers, like most other folks, take time off for the traditional summer vacation. During a severe crisis, such as the Great Recession of 2008-09, we were often granted access to fund managers on the very same day in which we initiated contact, because they were eager to make their case to anxious investors. During more typical corrections, we’re usually able to get fund managers on the phone by the next day.

While setting up interviews this month, I was struck by the fact that I ran into the typical seasonal issues—a number of managers were already on vacation or making their plans to get away.

Although my indicator is purely anecdotal, the consensus among fund managers seems to be “enjoy your summer.” The European debt crisis may still be simmering, the US economy may be weakening, and the emerging markets may be in the midst of a slowdown, but that doesn’t mean you should cancel your summer vacation.