Robert Half Inc. (NYSE:RHI) shareholders that were waiting for something to happen have been dealt a blow with a 26% share price drop in the last month. For any long-term shareholders, the last month ends a year to forget by locking in a 63% share price decline.

Even after such a large drop in price, you could still be forgiven for feeling indifferent about Robert Half's P/E ratio of 16.4x, since the median price-to-earnings (or "P/E") ratio in the United States is also close to 18x. While this might not raise any eyebrows, if the P/E ratio is not justified investors could be missing out on a potential opportunity or ignoring looming disappointment.

Robert Half hasn't been tracking well recently as its declining earnings compare poorly to other companies, which have seen some growth on average. One possibility is that the P/E is moderate because investors think this poor earnings performance will turn around. If not, then existing shareholders may be a little nervous about the viability of the share price.

If you'd like to see what analysts are forecasting going forward, you should check out our free report on Robert Half.

What Are Growth Metrics Telling Us About The P/E?

There's an inherent assumption that a company should be matching the market for P/E ratios like Robert Half's to be considered reasonable.

If we review the last year of earnings, dishearteningly the company's profits fell to the tune of 44%. The last three years don't look nice either as the company has shrunk EPS by 75% in aggregate. Accordingly, shareholders would have felt downbeat about the medium-term rates of earnings growth.

Looking ahead now, EPS is anticipated to climb by 8.7% during the coming year according to the eight analysts following the company. With the market predicted to deliver 15% growth , the company is positioned for a weaker earnings result.

In light of this, it's curious that Robert Half's P/E sits in line with the majority of other companies. Apparently many investors in the company are less bearish than analysts indicate and aren't willing to let go of their stock right now. Maintaining these prices will be difficult to achieve as this level of earnings growth is likely to weigh down the shares eventually.

What We Can Learn From Robert Half's P/E?

With its share price falling into a hole, the P/E for Robert Half looks quite average now. We'd say the price-to-earnings ratio's power isn't primarily as a valuation instrument but rather to gauge current investor sentiment and future expectations.

Our examination of Robert Half's analyst forecasts revealed that its inferior earnings outlook isn't impacting its P/E as much as we would have predicted. Right now we are uncomfortable with the P/E as the predicted future earnings aren't likely to support a more positive sentiment for long. This places shareholders' investments at risk and potential investors in danger of paying an unnecessary premium.

Of course, you might find a fantastic investment by looking at a few good candidates. So take a peek at this free list of companies with a strong growth track record, trading on a low P/E.

This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.