BOSTON ( TheStreet Ratings) -- When I last provided a review of the TheStreet Ratings' quantitative equity model on April 18, the S&P 500 Index stood at 1,305 and investors were starting to show signs of worry about the economy.

Standard & Poor's had also just put the U.S.'s AAA rating on a "negative" outlook, sending the stock market down by more than 2%, with the implication that the country's stellar rating was falling as debt was rising.

At the time, I noted that our model remained bullish, rating 37% of the 6,000 stocks we cover a "buy," up from 20% at the beginning of 2010. With the S&P 500 down 3.7% since then, the model has become even more bullish, with 40% (as of June 22) now rated "buy."

As I pointed out in another recent article, stocks are cheap on a price-to-earnings basis, with the S&P 500 trading at just 13 times 2011 estimates. So what does the model like? I took a look at its favorite industries, and scouted for what might have changed since the April review.

In the table below, I've listed the top 10 industries that have shown improved ratings since the last check on April 13.

Next to each industry, I listed the percentage of "buys," "holds" and "sells" along with a buy-sell ratio to gauge the level of bullishness. The last column compares this measure to last month. For example, while the model is somewhat neutral on paper and forest-products stocks, the ratings have improved since April, as three moved from "sell" to "buy."

I've broken down each industry to give some insight into what the model likes:

Household Products:

Of the 13 stocks in the industry, the model rates 11 (or 85%) "buy," a 46% improvement in the overall bullishness rating (%buy-%sell) from April 13.

Highest-Rated Stock: Church & Dwight ( CHD) -- Rating: A+

What's Changed?: Central Garden and Pet ( CENT) upgraded to "buy" from "hold," Ocean Bio Chem ( OBCI), upgraded to "buy" from "hold."

Paper and Forest Products:

Of the 20 stocks in the industry, the model rates nine (or 45%) "buy," a 30% improvement in bullishness (%buy-%sell) from April 13.

Highest-Rated Stock: Pope Resources ( POPE) -- Rating: B

What's Changed?: Pope Resources ( POPE), upgraded to "buy" from "hold," International Paper ( IP), upgraded to "buy" from "hold."

Trading Companies and Distributors:

Of the 33 stocks in the industry, the model rates 23 (or 70%) "buy," a 22% improvement in bullishness (%buy-%sell) from April 13.

Highest-Rated Stock: Grainger ( GWW) -- Rating: A+

What's Changed?: Houston Wire and Cable ( HWCC), upgraded to "buy" from "hold," Interline Brands ( IBI), upgraded to "buy" from "hold."

Auto Components:

Of the 37 stocks in the industry, the model rates 15 (or 41%) "buy," a 22% improvement in bullishness (%buy-%sell) from April 13. It's still an overall neutral.

Highest-Rated Stock: Motorcar Parts of America ( MPAA) -- Rating: A-

What's Changed?: Tenneco ( TEN) upgraded to "buy" from "hold," Standard Motor Products ( SMP), upgraded to "buy" from "hold."

Aerospace and Defense:

Of the 65 stocks in the industry, the model rates 39 (or 60%) "buy," a 20% improvement in bullishness (%buy-%sell) from April 13.

Highest-Rated Stock: Triumph Group ( TGI) -- Rating: A+

What's Changed?: Hexcel ( HXL), upgraded to "buy" from "hold," Triumph ( TGI), rating raised to A+ from B.

Containers and Packaging:

Of the 21 stocks in the industry, the model rates 14 (or 67%) "buy," a 20% improvement in bullishness (%buy-%sell) from April 13.

Highest-Rated Stock: Greif ( GEF) -- Rating: A-

What's Changed?: Owens-Illinois ( OI), upgraded to "buy" from "hold," MOD-PAC Corp. ( MPAC), upgraded to "buy" from "hold."

Building Products:

Of the 28 stocks in the industry, the model rates seven (or 25%) "buy," a 19% improvement in bullishness (%buy-%sell) from April 13. Still, it's an overall negative.

Highest-Rated Stock: Simpson Manufacturing ( SSD) -- Rating: A+

What's Changed?: Armstrong World Industries ( AWI), upgraded to "buy" from "hold," Owens Corning ( OC), upgraded to "buy" from "hold."

Energy Equipment and Services:

Of the 70 stocks in the industry, the model rates 28 (or 40%) "buy," an 18% improvement in bullishness (%buy-%sell) from April 13.

Highest-Rated Stock: Core Laboratories ( CLB) -- Rating: A

What's Changed?: Diamond Offshore ( DO), upgraded to "buy" from "hold."

Machinery:

Of the 132 stocks in the industry, the model rates 70 (or 53%) "buy," a 16% improvement in bullishness (%buy-%sell) from April 13.

Highest-Rated Stock: IDEX ( IEX) -- Rating: A

What's Changed?: Illinois Tool Works ( ITW), upgraded to "buy" from "hold," Met-Pro ( MPR), upgraded to "buy" from "hold."

Hotels, Restaurants and Leisure:

Of the 117 stocks in the industry, the model rates 50 (or 43%) "buy," a 16% improvement in bullishness (%buy-%sell) from April 13.

Highest-Rated Stock: McDonald's ( MCD) -- Rating: A+

What's Changed?: Wyndham Worldwide ( WYN), upgraded to "buy" from "hold," Red Robin Gourmet Burgers ( RRGB), upgraded to "buy" from "hold."
Equity research manager Chris Stuart, CFA, joined TheStreet Ratings after working as a senior investment analyst with Merrill Lynch covering small-cap equity and alternative investment strategies. Prior to that, Stuart worked for One Beacon Insurance as an actuarial analyst and at H&R Block as a financial adviser. Stuart earned his bachelor's degree in finance from the University of Massachusetts, Amherst. He holds a Chartered Financial Analyst (CFA) designation and is a member of the Boston Security Analysts Society (BSAS) and the CFA Institute.