funds. Furthermore, while it may be the case that this positive externality increases the overall levels of investment in the Islamic and Socially responsible funds, the responsiveness to changes in risk and returns (a key feature of our design) remain unaffected.

We now turn to the control and three treatments. As mentioned, each of our conditions carried the same decision structure, with the same risk-returns on the two funds. They varied simply in the type of fund label assigned to fund X (fixed) and fund Y (variable). Table 2 reports the differences between the conditions.

**Table 2: Experimental design**

||**Fund X**|**Fund Y**|**Observations**|
|---|---|---|---|
|**Control**|Traditional|Traditional|61|
|**Treatment 1**|Traditional|Islamic|61|
|**Treatment 2**|Traditional|Sociallyresponsible|61|
|**Treatment 3**|Sociallyresponsible|Islamic|61|

In the experiment, subjects are asked to split the 5,000 token investment, and are informed that they will keep the returns, but return the principle back to the experimenter. This was done to make the earnings salient and to keep the costs of the experiment manageable. Comparing investment in fund Y across treatments allows us to identify the impact of fund type on investor behavior, i.e., the impact of Islamic funds (Treatment 1 vs control) on investor behavior, or the impact of socially responsible funds (Treatment 2 vs control) on investor behavior. Our third treatment is an additional treatment we ran to compare investor behavior in Islamic funds, when the alternative is either traditional or socially responsible (Treatment 1 vs Treatment 3) which then allows us to directly compare the effects of the availability of alternative investments and the degree to which behavior in Islamic investing mimics socially responsible investing. The session is followed by a brief survey measuring gender, age, financial literacy, risk preferences, state of personal finances, experience investing in mutual funds (outside of the experiment), beliefs that the charity was paid in line with the instructions, and the overall clarity of the instructions. We use these variables as controls in the appropriate specifications in the results.

# _Measuring preferences_

We implement a survey and two dictator games that give us additional measures that are used in the analysis. We ask for subject gender; age; and current financial conditions (response to the question “How would you describe the state of your own personal finances these days?”). We also measure subjects understanding of the instructions (which is critical for us as English is a second language, and we communicate a few complex concepts) which is a response to the question “Were the instructions clear?”. Among the subjects, 96% responded with either “Most of the time” (40%) or “Always” (55%), giving us some confidence in the validity of the results. We also ask subjects whether they believed that we would pay the mosque or the charity in line with the instructions (response to the question “To what extent do you agree with the following statement: I am confident that the charity and mosque will be paid in accordance with the instructions.” This is important for low trust environments like Pakistan. Over 90% of our sample reported being moderately confident (29%), very confident (37%) or extremely confident (25%). Previous investment experience is measured using the response to the question “Have you ever invested in a mutual fund?” (only 4.5% - 11 subjects said yes to this question). Table 3 presents these summary statistics.

In addition to the controls above, it is important to measure religious and social preferences as accurately as possible for our purposes. For these we utilize incentivized measures: