Nichel Gonzalez Foto: Psykologiska institutionen/HD

Nichel Gonzalez

Forskare, Postdoktor

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Arbetar vid Psykologiska institutionen
Telefon 08-16 28 79
Besöksadress Frescati hagväg 14
Rum 225
Postadress Psykologiska institutionen 106 91 Stockholm

Om mig


Mitt främsta forskningsområde är beteendeekonomi. För min kommande avhandling undersöker jag hur ränteinformation påverkar långsiktiga investeringsbeslut med fokus på olika individuella strategier. I dessa studier fokuserar jag även på bedömningar av ackumulerat värde som följd av olika räntor.

Jag har även intresserat mig för beslutsfattandeforskning som rör trafik, produktion och medicinska beslut. I denna forskning ligger fokus på systematiska felslut, individuella bedömningsstrategier och justering av egna minnen för att stötta sitt beslut.



  • Beslutsfattande
  • Statistik


I urval från Stockholms universitets publikationsdatabas
  • 2018. Ola Svenson (et al.). Scandinavian Journal of Psychology 59 (2), 127-134

    Cognitive representations of decision problems are dynamic. During and after a decision, evaluations and representations of facts change to support the decision made by a decision maker her- or himself (Svenson, 2003). We investigated post-decision distortion of facts (consolidation). Participants were given vignettes with facts about two terminally ill patients, only one of whom could be given lifesaving surgery. In Study 1, contrary to the prediction, the results showed that facts were distorted after a decision both by participants who were responsible for the decisions themselves and when doctors had made the decision. In Study 2 we investigated the influence of knowledge about expert decisions on a participant's own decision and post-decisional distortion of facts. Facts were significantly more distorted when the participant's decision agreed with an expert's decision than when the participant and expert decisions disagreed. The findings imply that knowledge about experts' decisions can distort memories of facts and therefore may obstruct rational analyses of earlier decisions. This is particularly important when a decision made by a person, who is assumed to be an expert, makes a decision that is biased or wrong.

  • 2018. Ola Svenson, Nichel Gonzalez, Gabriella Eriksson. Judgment and decision making 13 (5), 401-412

    We used correlation and spectral analyses to investigate the cognitive structures and processes producing biased judgments. We used 5 different sets of driving problems to exemplify problems that trigger biases, specifically: (1) underestimation of the impact of occasional slow speeds on mean speed judgments, (2) overestimation of braking capacity after a speed increase, (3) the time saving bias (overestimation of the time saved by increasing a high speed further, and underestimation of time saved when increasing a low speed), (4) underestimation of increase of fatal accident risk when speed is increased, and (5) underestimation of the increase of stopping distance when speed is increased. The results verified the predicted biases. A correlation analysis found no strong links between biases; only accident risk and stopping distance biases were correlated significantly. Spectral analysis of judgments was used to identify different decision rules. Most participants were consistent in their use of a single rule within a problem set with the same bias. The participants used difference, average, weighed average and ratio rules, all producing biased judgments. Among the rules, difference rules were used most frequently across the different biases. We found no personal consistency in the rules used across problem sets. The complexity of rules varied across problem sets for most participants.

  • Avhandling (Dok) Interest to Reinvest
    2018. Nichel Gonzalez (et al.).

    The general aim of this thesis is to contribute to the understanding of how numerical information, such as asset values and interest rates, influences inexperienced investors in their investment decisions. In relation to this, I have investigated the participants’ own understanding of what information they rely on for their own decisions. I have also investigated how their willingness to wait for greater rewards is related to their investment decisions. Importantly, I have distinguished between average behavior (group behavior) and individual behavior in an attempt to better describe how different information is important for different individual investors.

    On the group level the only reliable predictor of investment size was whether there was a gain or a loss during the period before the investment. However, how large the gain or loss was had no, or very limited, influence on investment size. When looking at each investor’s individual decisions, it was revealed that a substantial number of participants actually did rely on information other than only the gain/loss information, for example, the interest rates of forecasted developments of the different investment prospects. Furthermore, a substantial number of participants relied heavily on one of the cues; at least 50% of their investments were explained by the cue relied upon.

    Interestingly, very few participants’ investments were influenced by their own judgments of future asset outcomes. Furthermore, the participants’ willingness to invest in funds with guaranteed gains was used as a proxy for time preference (willingness to wait for greater rewards instead of accepting lesser rewards in the present). Time preference was relevant for investments but it did not relate to judged asset outcomes. This indicates that people may be more influenced by their future-oriented preferences rather than by their future-oriented beliefs (judgments).

    To conclude, these findings suggest that people use a preference-driven simplified strategy for investments and that these strategies differ substantially between individuals. This corroborates the idea about heuristic thinking, meaning that people simplify their decisions in a way that can deviate from normative value-maximizing behavior. For practical application, it is important to note the variety of strategies among individuals. This variety suggests that there is no “one size fits all” solution regarding instructions that can be given to inexperienced investors. The participants’ very limited insight into what information they relied upon is reason for researchers and advisors to understand the individuality in strategies in greater depth.

  • Nichel Gonzalez.

    According to Prospect theory, we judge and decide in relation to a reference point. Furthermore, it has been found that we perceive amounts differently depending on if people are asked about percentages or actual amounts of currency. Therefore, in this study, the effects of response format (amount of SEK or percentage of assets) on long term investment decisions were investigated. I also investigated the relation between investments and subjective judgments of asset accumulations, as well as time preference (the willingness to wait for greater rewards). Average investments were greater followings gains compared to losses, but there was no statistically significant effect of response format. The gain/loss factor was the best predictor of average investments, independent of gain/loss size. Judgments of accumulated assets were weakly related to investments and time preference, but time preference was closely related to investments. I also wanted to know how participants used the information in the problems. Therefore, how important different kinds of information were for each individual participant’s investments was analyzed. This revealed that that it was more common in the currency condition, compared to the percentage condition, to rely heavily on forecasted future interest rates, but also to ignore this information completely. In conclusion, information processing is very diverse and how people are asked to invest can change what information they focus on or ignore.

  • 2017. Nichel Gonzalez. Journal of Behavioral and Experimental Finance 15, 59-65

    This study investigated how accumulating gains and losses, described as annual interest rates, influenced investment behavior. Investments after gains were on average greater than after losses regardless of the gain and loss interest rates. However, greater variance of interest rates gave some weight to that variable for gains but not for losses. We also analyzed the influence from different information cues on each participant’s investments. This revealed that interest rates influenced participants very differently, some invested more with increasing gains, or with increasing losses, while others invested less. This finding explained why interest rate was a weak predictor on the group level. Furthermore, our individual analyses showed an increased sensitivity to interest rates and judged future asset accumulations when the interest rate variance was greater. Finally, subjective reports of the importance of different cues for the participants’ own investments showed only some understanding of the cues influence on the investments.

  • 2014. Nichel Gonzalez, Ola Svenson. Polish Psychological Bulletin 45 (1), 29-35

    Previous research showed that accumulations of capital following stationary interest rates are underestimated byhuman judges. Hyperbolic discounting was suggested as a descriptive and explanatory model for this phenomenon. First,we investigated judged accumulated capital after a period of annual growth and decline. The degree of underestimationincreased with accumulated growth and the results supported hyperbolic discounting as a descriptive model on the grouplevel. However, the hyperbolic model did not apply to the data for one third of the participants. Second, we investigatedhow investment decisions were related to capital accumulation before the investments and to judgments of the possibleoutcomes of the future investments. To our surprise, the participants’ judgments of expected future accumulated capitaldid not add predictive power to predictions based on whether there was growth or decline before the investment decision.Unfortunately this strategy leads to suboptimal investment decisions.

  • 2014. Ola Svenson, Nichel Gonzalez, Gabriella Eriksson. Judgment and decision making 9 (5), 465-478

    Svenson (2011) showed that choices of one of two alternative productivity increases to save production resources (e.g., man-months) were biased. Judgments of resource savings following a speed increase from a low production speed linewere underestimated and following an increase of a high production speed line overestimated. The objective formula for computing savings includes differences between inverse speeds and this is intuitively very problematic for most people.The purpose of the present studies was to explore ways of ameliorating or eliminating the bias. Study 1 was a control study asking participants to increase the production speed of one production line to save the same amount of production resources(man-months) as was saved by a speed increase in a reference line. The increases judged to match the reference alternatives showed the same bias as in the earlier research on choices. In Study 2 the same task and problems were used as in Study 1,but the participants were asked first to judge the resource saving of the reference alternative in a pair of alternatives before they proceeded to the matching task. This weakened the average bias only slightly. In Study 3, the participants were askedto judge the resources saved from each of two successive increases of the same single production line (other than those of the matching task) before they continued to the matching problems. In this way a participant could realize that a secondproduction speed increase from a higher speed (e.g., from 40 to 60 items /man-month) gives less resource savings than the same speed increase from a first lower speed (e.g., from 20 to 40 items/man-month. Following this, the judgments of thesame problems as in the other studies improved and the bias decreased significantly but it did not disappear. To be able to make optimal decisions about productivity increases, people need information about the bias and/or reformulations of the problems.

  • 2012. Ola Svenson, Gabriella Eriksson, Nichel Gonzalez. Accident Analysis and Prevention 45, 487-492

    The purpose of speed limits is to keep driving speed low enough for drivers to be able to pay attention to relevant information and timely execute maneuvers so that the car can be driven in a safe way and stopped in time. If a driver violates a speed limit or drives too fast she or he will not be able to stop as quickly as from a slower speed. We asked participants to imagine that they themselves had driven a car outside a school at a speed of 30 km/h when a child suddenly had rushed into the street. From this speed it was possible to stop the car just in front of the child after braking as quickly and forcefully as possible. We then asked the participants to imagine that they drove the same street at a higher speed of 50 km/h and the child appeared at the same place as before. At what speed would the car hit the child after braking in the same way as before? This kind of problems were presented in three studies and the results showed that the judged speeds of collision were always underestimated in different hypothetical driving context scenarios by judges differing in numerical skills. This indicates an overly optimistic view on the possibilities to reduce speed quickly if the driving speed is too fast, which is an important component of attitudes towards speed limits, their legitimacy and recommended driving speeds. Further implications of the results were discussed last.

Visa alla publikationer av Nichel Gonzalez vid Stockholms universitet

Senast uppdaterad: 19 december 2019

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