Impact investing aims to generate both a positive social and/or environmental impact and a financial return. Yet as this inchoate and still-evolving field slowly gains traction, there's a philosophical debate about whether pursuing one of those goals might come at the expense of the other.

It's an issue raised in a survey released late last year by the Global Impact Investing Network (GIIN) and J.P. Morgan that captured the views of 52 organizations and fund managers engaged in impact investing, including members of GIIN's Investors' Council comprising some of the heavyweights in impact investing circles. Among other things, it asked respondents their views on returns, risk and impact measurement practices, and their general take on this market.

One of the questions posed to survey participants whether they felt a trade-off between financial returns and the project's intended impact is necessary when making impact investments. Sixty percent said no; 40% said yes.

And in response to a corollary question on whether they'd sacrifice financial returns for greater impact, 62% of investors said yes versus 38% who said no. In that vein, 46% of respondents say they try to balance both aims, while 54% said they optimize one while setting either an impact floor or a financial floor on their investment.

But that doesn't mean impact investors are willing to shell out large sums of money just for the sake of doing good.

"Impact investors are incredibly diverse in their motivations and goals for their investments," says Amit Bouri, director of strategy and development at GIIN, a New York City-based non-profit group focused on growing the scale and effectiveness of impact investing. "But all impact investors are very focused on returns."

Those return expectations can vary depending on the types of issues, geographies and communities targeted by particular impact investments. But in general, he notes, impact investors require at least market rate returns.

"These market rate returns would be what you would expect from a conventional investment of a similar type," Bouri says.

Impact investments can come in different shapes and sizes--equity, loans or providing guarantees to facilitate third-party investment. They can promote economic growth, deliver products and services to underserved population or tackle environmental issues.

As for their primary investment objective, 58% of survey respondents said social causes were their top priority, while 8% said they pursued a strictly environmental objective. Thirty-four percent said they equally pursue both aims.

In assessing this nascent industry, survey participants said the top challenge to growth was its lack of a track record. The next major challenges were shortage of quality investment opportunities and inadequate impact measurement practices. Other potential growth obstacles cited include lack of common vernacular for talking about impact investing, few exit opportunities and insufficient collaboration among investors.

The general consensus among respondents (75%) was that impact investing is in its infancy and still growing. Another 19% believe it's about to take off, while the remaining 6% said it's a lot of talk but not much action. Bouri says that latter number doesn't surprise him.

"It echoes our perspective on where the market is," he notes, adding that despite the tangible actions and momentum generated by impact investments, it's an area that's still far from reaching its potential.

"Some respondents felt the talk was too far ahead of the activity," Bouri says. "But it's encouraging that a greater number of people feel it's about to take off."