  Decision markets are mechanisms for selecting one among a set of actions
based on forecasts about their consequences. Decision markets that are based on
scoring rules have been proven to offer incentive compatibility analogous to
properly incentivised prediction markets. However, in contrast to prediction
markets, it is unclear how to implement decision markets such that forecasting
is done through the trading of securities. We here propose such a securities
based implementation, and show that it offers the same expected payoff as the
corresponding scoring rules based decision market. The distribution of realised
payoffs, however, might differ. Our analysis expands the knowledge on
forecasting based decision making and provides novel insights for intuitive and
easy-to-use decision market implementations.
