Charles Schwab Chief Investment Strategist Liz Ann Sonders says she thinks the recent economic slowdown doesn’t signal the coming of another recession, and says she remains optimistic on stocks and the economy over the longer term.

“We remain of the view that this slowdown is a soft patch, not a sign of an impending second recession (the dreaded ‘double-dip’),” Sonders writes in recent commentary on Schwab’s web site. She says temporary factors, including the impact of the Japan disaster on the global supply chain, rising oil prices, and bad weather, have contributed to the market’s and economy’s malaise in the past couple months. She says we’re “not out of the woods” yet, but adds that the “volatility and weakness we’re experiencing is the norm following a severe financial crisis”.

Sonders says risks for the economy include a further and steeper decline in housing than what’s expected; a harder-than-expected landing for China’s economy; a weaker-than-expected job market; and troubles in the Eurozone and Middle East. But she says there are also hopeful signs. Among them: The supply-chain issues in Japan are improving more quickly than expected, and companies are indicating a willingness to spend more on capital expenditures and hiring.

Sonders also provides some interesting data on how the current low investor sentiment is a bullish sign for long-term stock returns. In the short-term, she says she wouldn’t be surprised to see further declines in the market. “But longer term, our optimism is not meaningfully dented,” she says. “More than half of the S&P 500’s stocks are now oversold and setting up for bounces, at least. Stocks are trading at a low 13 multiple on 2011’s expected earnings, which do not appear to be pie-in-the-sky.”