Image source: LendingMemo, republished under CC BY 2.0.

U.S. stocks are kicking off the week little changed, with the S&P 500 (SNPINDEX: ^GSPC) and the Dow Jones Industrial Average (DJINDICES: ^DJI) (DJINDICES: $INDU) down 0.09% and 0.04%, respectively, at 12:09 p.m. ET.

If you're a serious investor, even if you're a pure stock picker, it's always interesting to keep an eye on factors that impact the stock market. As a direct cash return on stock investments, dividends are one such factor that is hardly incidental.

And here's an observation regarding dividends that doesn't appear to be incidental, either: In the first quarter, the S&P 500's cash dividends per share fell relative to the previous quarter, breaking a seven-quarter streak of record dividends for the index.

A closer look at the data from S&P Dow Jones Indices suggests the decline could well be more than a statistical blip. Indeed, since the fourth quarter of 2000, the trailing-12-month dividend payout ratio has only been higher than it is currently (43.6% at the first quarter) during five quarters spanning the second half of 2008 through the third quarter of 2009.

(The dividend payout ratio is here defined as S&P 500 cash dividends per share divided by the S&P 500's operating earnings per share.)

That period was significant: As the financial crisis took hold, the payout ratio spiraled higher, more than doubling, as earnings collapsed faster than companies were willing to reduce or eliminate their dividends (in 2008, the S&P 500's cash dividends per share were nearly twice its as-reported earnings!).

Furthermore, those dividends anchor the S&P 500's valuation and, therefore, its potential price appreciation. In a period of historically low interest rates, investors are not pooh-poohing the cash yield on the index and appear to be unwilling to jeopardize that yield by pushing stock prices up faster than the rate at which dividends are growing.

The dividend yield is equal to the ratio of dividends to the value of the index; an index that is rising faster than dividends implies a declining dividend yield.

In fact, since the start of 2014, the dividend yield has been trending upwards; it currently stands at 2.19%. If interest rates stay at rock-bottom levels, we can expect investors' inclination toward dividends to remain undimmed. Under that scenario, only rising dividends can produce further price gains in the index.

With the payout ratio at a high level, rising dividends, would, in turn, require rising earnings (that sounds reasonable enough -- dividends are paid out of earnings).

Conclusions: This analysis suggests that the S&P 500 may struggle to post any appreciable gains in the near term as the energy and materials sectors continue to struggle through the brutal bear market in commodities markets. There is one ace in the hole, however, that could help mitigate this process: Financials. Indeed, some of the largest weightings in the sector, including Citigroup and Bank of America have yet to achieve normalized dividend payout ratios/dividend payout yields.