Preposition for use of "proxy" as an adjective

I would like to say that some thing A is used as a proxy for another thing B. How would I express this with "proxy" as an adjective?

To me,

A is proxy to B and less expensive.

sounds more natural than

A is proxy for B and less expensive.

Are to and for both fine, is only one of them correct, or is neither correct?

Thanks

Solution 1:

A is a proxy for B and less expensive.

The interest rate is a proxy for the cost of credit, and the real effective exchange rate is a proxy for relative prices. Lawrence Pelzer, New Developments in Macroeconomics Research (2006)

If social class is a proxy for how we live, each SES indicator is a proxy for a somewhat different dimension of that life. Proceedings of the 1993 Public Health Conference on Records and Statistics; Toward the Year 2000

Proxy is noun (and a verb), but you can use it attributively as a modifier.

A common solution is to do a proxy vote, which means that you assign another person to vote in your place. Jennifer Reuting; Limited Liability Companies For Dummies (2008)

For example, according to officials at one company we interviewed, if a proxy vote is to be cast not in accordance with the plan's guidelines, then the vote is decided by the plan's proxy committee ... GAO; Pension Plans

Charles Bridges had sued the stockholder committee for libel, complaining that the proxy letter had falsely charged that his management was incompetent and that the company had deceived shareholders about the company's finances. Diana B. Henriques; The White Sharks of Wall Street (2001)

On a practical note, there are 83 observations for which the time between the board date and the proxy date exceeds 60 days, and 1 observation with a 290 days difference between the board and proxy dates. J. Choi and S. Dow; Institutional Approach to Global Corporate Governance (2008)