Governments
usually provide subsidies based on overall adoption targets, such as the number
of cars or solar
panels they would like to see purchased over a period of time. But greentechnologies
are often new products, and no one really knows how many consumers are waiting
to buy them.
Image: MIT News
(January 21, 2016) Governments
often offer subsidies to consumers for clean-technology products, from home
solar panels to electric vehicles. But what are the right levels of subsidy,
and how should they be calculated? As a new paper co-authored by MIT
researchers shows, governments can easily make subsidies too low when they
ignore a basic problem: Consumer demand for these products is usually highly
uncertain.
Indeed, the paper’s analysis suggests this has already
happened in the case of the Chevy Volt, an electric car introduced in 2010 that
suffered slow initial sales before gaining more traction in the marketplace.
“The government will miss their target by a lot when
ignoring demand uncertainty,” says Georgia Perakis, the William F. Pounds
Professor of Management at the MIT Sloan School of Management and a co-author
of the paper.
While discussion of “demand uncertainty” might sound a bit
abstract, it matters. Governments usually provide subsidies based on overall
adoption targets, such as the number of cars or solar panels they would like to
see adopted over a period of time. But green technologies are often new
products, and no one really knows how many consumers are waiting to buy them.
Some models of subsidies assume a steady ratio between the
dollar amount of the subsidy and the total number of cars or solar panels that
will be sold. But as the new paper indicates, that’s not quite the right
approach. Given uncertain markets, subsidy levels don’t correlate steadily with
sales. Instead, it takes relatively high subsidy levels to kick-start a certain
amount of business; then a more gradual increase can help achieve higher sales.