So far in 2013 the Dow Jones Industrial Average (DJI) is up 15.1%. This could suggest challenges ahead as the second half of the year commences – as any further gains could put into question the sustainability of double-digit returns. In the absence of high interest rates, income-paying stocks become an increasingly attractive investment. [Read more from Kapitall on the Dow Jones here.] On the Dow Jones, four companies with the highest dividend yield might still attract investors. Note that telecom companies pay the highest yield, while pharmaceuticals are the most expensive when the Price to Sales ratio is used: AT&T (T) has a forward yield of 5.07%. The company was added to Goldman Sachs’ list of favorite dividend investments with unusually high volatility. AT&T had wanted to build a position in Telefonica (TEF), a Spanish telecom firm, but ultimately did not recevie the blessing of the Spanish government. The company's prepaid plans have seen b etter network access, and 4G support was given to the GoPhone plans. This should give customers more options and greater value for service. Click on the images below to see performance data and ratings over time. Data sourced from Zacks Investment Research.Verizon Communications (VZ) is also on Goldman Sachs’ dividend list. Shares pay a dividend that yields 4.1%. Verizon Wireless completed the rollout of 4G LTE, and claims the service is now available to 95% of the U.S. population. The company is reportedly entering the Canadian markets to grow. For a bid of around $700 million, Verizon is offering to buy Wind Mobile. The Canadian market is in need for greater competition, as consumers often have to sign up for a 3-year plan before smartphones are subsidized at a reasonable price. In the pharmaceutical space, Johnson & Johnson (JNJ) offers a dividend yielding 3.1%. JNJ broke past a long time range of around $70 at the beginning of 2013: But recent developments among some of the company's prescription drugs have not brought good news. In early June, the company issued a recall for 32 million packages of Cilest, a birth control pill. Two of the hormones were released more slowly than it was supposed to. Razadyne, which is used to treat Alzheimer’s, could have the side benefit of reducing the risk of heart attacks and death. The other pharmaceutical stock on our radar is Pfizer (PFE), and the company's shares have a dividend that yields 3.4%. Currently, the company is buying back $10 billion in shares. This is on top of the $3.9 billion that remains under the current buyback plan.